EPA9 0 4-R-9 0-001
CUMULATIVE IMPACT ASSESSMENT
IN THE PEARL RIVER BASIN,
MISSISSIPPI AND LOUISIANA
James G. Gosselink, Charles E. Sasser, Lisa A. Creasman,
Susan C. Hamilton, Erick M. Swenson, and Gary P. Shaffer
COASTAL ECOLOGY
INSTITUTE
LSU-CEI-90-03
Coastal Ecology Institute
Center for Wetland Resources • Louisiana State University • Baton Rouge, LA 70803-7503

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EPA9 04-R-90-001
CUMULATIVE IMPACT ASSESSMENT
IN THE PEARL RIVER BASIN,
MISSISSIPPI AND LOUISIANA
James G. Gosselink, Charles E. Sasser, Lisa A. Creasman,
Susan C. Hamilton, Erick M. Swenson, and Gary P. Shaffer
Coastal Ecology Institute
Center for Wetland Resources
Louisiana State University
Baton Rouge, Louisiana 70803-7503
LIBRARY
US EPA Region 4
AFC/9th FL Tower
61 Forsyth St. S.W.
Atlanta, GA 30303-3104
Prepared for
Office of Wetlands Protection
U.S. Environmental Protection Agency
REGION 4
LIBRARY
US EPA Region 4	L
AFC/9th FL Tower
e 61 Forsyth St. S.W.	^ epa.gov
Atlanta, GA 30303-3104
WEB site: http://www.epa.gov/docs/Region4Wet/wetlands.html
LSU-CEI-90-03
November 1990

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DISCLAIMER
The opinions, findings, conclusions, or recommendations expressed in this report
are those of the authors and do not necessarily reflect the views of the Office of Wetlands
Protection, U.S. Environmental Protection Agency.
This report should be cited:
Gosselink J.G., C.E. Sasser, L.A. Creasman, S.C. Hamilton. E.M. Swenson, and
G.P. Shaffer. 1990. Cumulative impact assessment in the Pearl River basin, Mississippi
and Louisiana. Coastal Ecology Institute, Louisiana State University, Baton Rouge.
LSU-CEI-90-03. 260 pp.

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CONTENTS
Page
Acknowledgments 	ix
Conversion Factors and Abbreviations	xi
Abstract		xiii
CHAPTER 1: INTRODUCTION	 1
Background 	 3
The Wetland Resource 	3
Regulatory Jurisdiction 	3
Cumulative Impacts	4
Landscape Ecology and Natural Resource Conservation 	6
Purpose of the Study 	 7
Pearl River Basin: General Description 	8
Location and Size	8
Climate	 12
Landforms and Vegetation 	 12
Geology and Soils	 15
Socioeconomic Development	 15
Population	 15
Employment 	 17
Labor Force and Income	 17
Protected Areas	 20
References 	 23
CHAPTER 2: LAND USE IN THE PEARL RIVER BASIN	 25
Introduction		27
Methods 		27
Description of the Study Area		27
Inshore Study Area		29
Land Use Mapping 			29
Historical Land Use Data 			31
Forest Patch Analysis		31
Stream Edge Habitat		31
Offshore Study Area		31
Results 		31
Inshore Study Area		31
Historical Land Cover Trends 		31
Stream Edge Habitat		33
Forest Patch Analysis		50
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CONTENTS (Continued)
Page
Offshore Study Area	 50
Land Cover	 50
Discussion 	 50
Inshore Study Area	 50 .
Historical Land Cover	 50
Sub-basin Trends	 58
Stream Edge Habitat	 59
Forest Patch Analysis	59
Offshore Study Area		60
References 	 63
CHAPTER 3: HYDROLOGY OF THE PEARL RIVER BASIN	 65
Introduction		67
Hydrology of the Pearl River Basin 		67
The Basin				67
The Offshore Area 		73
Historical Changes		75
Stage and Discharge Analysis		76
The Data Base 		76
Analysis Procedures		82
Results and Discussion		89
Conclusions 		97
- References 		98
CHAPTER 4: WATER QUALITY OF THE PEARL RIVER BASIN,
MISSISSIPPI AND LOUISIANA	 101
Introduction		103
Phosphorus		103
Nitrogen 		104
Materials and Methods		104
Site 			104
Water Quality Data Analyses		107
Nutrient Flux Measurements		107
Results 		108
Water Quality Trends 		108
Basinwide 		108
Turbidity		108
Phosphorus 		112
Nitrogen 		112
Site-Specific Results		112
Nutrient Fluxes 		115
Discussion 		121
Conclusions 		126
References 		128
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CONTENTS (Continued)
Page
CHAPTER 5: FAUNAL DIVERSITY AS AN INDEX IN CUMULATIVE
IMPACT ASSESSMENT-PEARL RIVER BASIN 		131
Introduction		133
Temporal Changes in Bird Species Richness		134
Introduction 		134
Methods 		134
Results 		136
Wading Birds		143
Waterfowl			143
Temporal Changes in Fish and Other Wildlife Species Richness		143
Fisheries 		143
Anadromous Fish			145
Other Wildlife		148
Indicator Species 		149
Endangered and Threatened Species 		149
Discussion and Conclusions 		149
Birds 		151
Fisheries 		154
Indicator and Threatened/Endangered Species		154
References 		155
CHAPTER 6: SUMMARY AND SYNTHESIS		159
Introduction		161
Indices of Landscape Structure and Function		161
Summary of Land Use, Hydrology, Water Quality, and Biota 		164
Land Cover		164
Hydrology		165
Water Quality		166
Biota 		166
Pearl River Basin as an Integrated Landscape 		167
Interaction of Structure and Process 	-		167
Spatial Pattern of Structure and Process 		168
Onshore-Offshore Interactions		172
The Influence of the River on the Estuary 		172
Influence of the Estuary on the Pearl River Basin		176
Development of Goals and Plans		177
Goals 		178
Implementation Strategies		178
References 		184
APPENDIX A: Statistical Analysis of Stage and Discharge Records		187
APPENDIX B: Breeding Bird Surveys, Pearl River Basin 		219
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CONTENTS (Continued
APPENDIX C: Land Cover Classification of Christmas Bird
Survey Sites in the Pearl River Basin	
APPENDIX D: Species List of the Pearl River Basin ....
APPENDIX E: Habitat Preference of Endangered and Thrf
in the Pearl River Basin 	
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ACKNOWLEDGMENTS
The Office of Wetlands Protection, U.S. Environmental Protection Agency,
Washington, D.C., funded the production of this report, under Cooperative Agreement
No. CX8146-01-0 to the Coastal Ecology Institute, Louisiana State University. We thank
the U.S. Geological Survey in Jackson, Mississippi, particularly Mickey Plunkett, for
supplying the daily stage and discharge records used in Chapter 3 in a computer-compatible
format. We thank the same office for allowing us to go through their original data records
to obtain additional data. We thank Fred Keeter of the U.S. Soil Conservation Service in
Jackson, Mississippi, for his time and summary of SCS projects within the Pearl River
basin. We thank Dr. James Cowan, Jr., of Chesapeake Biological Laboratory, University
of Maryland System, who contributed the section on fisheries in Chapter 5. Thanks also to
Sam Droege of the U.S. Fish and Wildlife Service, Maryland, for supplying breeding bird
survey data; Dr. Robert Hamilton of the Louisiana State University School of Forestry,
Wildlife, and Fisheries for bird habitat classifications and critical review; and Kathy Joiner
for assistance with data preparation and statistical analysis.
ix

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CONVERSION FACTORS AND ABBREVIATIONS
Multiply inch -pound units
By
To obtain metric units
inch (in.)
25.4
millimeter (mm)
cubic inch (in3)
16.39
cubic centimeter (cm3)
square inch (in2)
6.452
square centimeter (cm2)
foot (ft)
0.3048
meter (m)
square foot (ft2)
929
square centimeter (cm2)
square foot (ft2)
0.09290
square meter (m2)
cubic foot (ft3)
0.02832
cubic meter (m3
cubic foot per second (ft3/s)
0.02832
cubic meter per second (m3/s)
mile (mi)
1.609
kilometer (km)
square mile (mi2)
2.590
square kilometer (km2)
cubic mile (mi3)
4.168
cubic kilometer (km3)
mile per hour (mi/h)
1.609
kilometer per hour (km/h)
acre
4,047
square meter (m2)
acre
0.4047
hectare
acre-foot (acre -ft)
1,233
cubic meter (m3)
ounce, avoirdupois (oz)
28.35
gram (g)
ounce, fluid (fl. oz)
0.02957
liter (L)
pint (pt)
0.4732
liter (L)
quart (qt)
0.9464
liter (L)
gallon (gal)
3.785
liter (L)
Temperature in degrees Celsius (° C) can be converted to degrees Fahrenheit (°F) as
follows: °F=1.8 x °C +32.
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ABSTRACT
This report is an ecological assessment of the cumulative impacts of human
activities in the 2.5-million-ha Pearl River basin of Mississippi and Louisiana. The
analysis emphasizes landscape-level processes, to match the scale of cumulative impacts.
The first chapter summarizes relevant background material on landscape ecology and
resource conservation, wetlands, and regulatory jurisdiction, and gives a general
description of the basin. The next four chapters analyze land cover and use, hydrology,
water quality, and biota of the basin, with emphasis on changes in the past 20 years in
indicator parameters that reflect basin-level processes. The last chapter summarizes and
integrates material from the preceding five and suggests a possible scenario for managing
the resources of the basin.
Overall the Pearl River basin is in acceptable ecological condition. About two-
thirds of the basin area is forested, and the percentage has remained virtually unchanged
since the 1930s. Most of the rest of the basin is in agricultural production. Stability of
land use is reflected in the stability of hydrographs and rating curves. These have changed
little, if at all, over the period of record. Stream hydrology is driven primarily by rainfall,
infiltration, and evapotranspiration in the watershed. Water quality, as characterized by
total phosphorus concentration, is generally within standards suggested by EPA, that is,
less than 0.1 mg l"1. This reflects the predominance of forest cover and forest-buffered
streams in the watershed. Turbidity and total phosphorus were shown to be independent
of, or to increase only slightly with, streamflow-further evidence that the watershed is not
seriously disturbed. Finally, bird surveys revealed only small changes in composition over
the periods of record at different sites, and these changes were related to small changes in
local land use along the survey transects.
The basin functions as a whole, integrated by the flow of water from the watershed
surfaces across the floodplain wetlands into and down the collecting network of streams
and the Pearl River. An uninterrupted forested bottomland continuum is a key to
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preserving this integrated system, particularly the 40,000-ha swamp forest of the lower
Pearl River. The basin also interacts with the shallow offshore zone, where seawater
salinity is measurably diluted by river water, and river outwelling provides a significant
source of nutrients for aquatic plants and animals. Conversely, the river is a pathway for
inland salt intrusion from the estuary and for upstream migration of marine animals
Based on the ecological analysis we suggest one scenario for the management of the
basin. Management objectives should be directed towards ecological protection and
enhancement of the Pearl River basin. How this can be accomplished is illustrated by one
set of specific goals and by suggestions for strategies to attain these goals. The purpose of
such a basin-level management plan is to provide a framework for the long-term
management of the basin. When local conflicts arise, these goals provide a context that
gives managers a clear vision of the future and a mandate for responsible action.
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CHAPTER 1: INTRODUCTION

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A

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BACKGROUND
This study addresses general issues in environmental planning related to the
cumulative impacts of human activities on the environment, a class of disturbance that
regulatory agencies have found intractable. We introduce the following issues to set the
stage: (1) the loss of wetland resources, (2) the legal and administrative framework for
wetland regulation, (3) the nature of cumulative impacts, and (4) the use of ecological
principles (specifically landscape ecology principles) in environmental planning. We
follow this introduction with a cumulative impact assessment of the Pearl River basin of
Mississippi and Louisiana.
The Wetland Resource
Wetlands are threatened habitats. The U.S. Fish and Wildlife Service (USFWS)
(1981) reported that over half of the estimated 80 million ha of forested wetlands that
existed in the United States at the time of European settlement had been lost or converted to
other uses by 1975, and losses continue at a rate of 160,000-200,000 ha per year. Most
hard hit are the prairie pothole marshes of the north-central United States and the
bottomland hardwood forests of the southeastern states. Only about 30% of the latter
remain, and 23% of the loss has occurred in the last 25 years (Abernethy and Turner
1987).
Regulatory Jurisdiction
The stated objective of the Clean Water Act (CWA) at Section 101 is to "restore and
maintain the chemical, physical and biological integrity of the Nation's waters." In seeking
to meet this objective, the CWA established the Section 404 permit program to regulate
discharges of dredged or fill material in "waters of the United States," which include most
wetlands. Permits are issued by the Secretary of the Army acting through the U.S. Army
Corps of Engineers (USACE). No permit may be issued unless it meets the substantive
environmental criteria contained in the Section 404 (b) (1) Guidelines. The Guidelines
establish regulatory requirements used in the evaluation of proposed discharges and are
promulgated by EPA in conjunction with the USACE. (See 40 CFR, Part 230.)
In practice, the definition of "waters of the United States" has been broadly
interpreted by the courts to include wetlands (US. v. Holland 1975) and specifically most
bottomland hardwood forests (Avoyelles Sportmen's League v. Marsh 1983). Although
"normal" forestry and agricultural practices are statutorily exempt under Sec. 404(f) of the
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CWA, clearing of forested wetlands for conversion to agricultural production is generally a
regulated activity (Avoyelles Sportmen's League v. Marsh 1983; CWA 1988).
Considerable clearing of bottomland hardwood forests took place before the CWA was
passed, that is, before activities in wetlands became regulated. However, for both legal
and technical reasons it has continued to the present It has taken years and a series of
court decisions (Natural Resources Law Institue 1988) to clarify the geographic jurisdiction
of, and the types of activities exempted under, Sec. 404. For example, the U.S. Army
Corps of Engineers (USACE), which jointly administers the Sec. 404 program with the
U.S. Environmental Protection Agency (EPA), agreed to apply nationwide the decision in
Avoyelles Sportsmen's League v. Marsh only as recently as 1984, thus extending Sec. 404
regulatory coverage over most clearing, drainage, and channeling activities of wetlands
(National Wetlands Newsletter 1984). This change was not reflected in the regulations that
guide permit processing until November 1986 (51 Fed. Reg. 1986: 41,206-260; codified at
33 C.F.R, §§ 320-30). For additional information on land clearing activities subject to
Section 404 jurisdiction, see USACE Regulatory Guidance Letter No. 90-5, July 18,1990.
The CWA contains, in addition to permit requirements under Section 404 (b), other
regulatory tools to protect waters of the the United States. Under Section 230.80 of the
404 (b) (1) Guidelines, EPA (with the USACE), can identify wetlands or other waters, in
advance of the permitting process, as possible future disposal sites or as areas generally
unsuitable for disposal site specification. Identification of wetlands under Advance
Identification (ADID) is not a final agency action; applicants must still complete the 404
permitting process. The purpose of ADID is to gather information for better
decisionmaking in the 404 permitting process. Therefore, ADID is a tool for addressing
cumulative impacts and enabling a degree of regional planning. EPA also has authority
under Section 404 (c) to prohibit or restrict the use of waters of the United States for the
discharge of dredged or fill material (EPA's "veto" authority). EPA, as well as the U.S.
Fish and Wildlife Service and National Marine Fisheries Service, have agreements with the
USACE under Section 404 (q) of the CWA, that establish procedures for resolving
disagreements regarding individual Section 404 permit decisions. The Section 404 (q)
process has worked increasingly well as a means to improve decisionmaking and to
establish consistent policy among USACE Districts nationwide.
Cumulative Impacts
An important technical hindrance to protection of wetlands has been the difficulty of
managing the cumulative impacts of incremental clearing of small tracts (Lee and Gosselink
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1988). A cumulative impact is defined in the Council on Environmental Quality (CEQ)
regulations (which implement the National Environmental Protection Act of 1975 ) as:
the impact on the environment which results from the incremental impact of the
action when added to other past, present, and reasonably foreseeable future actions
regardless of what agency (Federal or non-Federal) or person undertakes such other
actions. Cumulative impacts can result from individually minor but collectively
significant actions taking place over a period of time (40 C.F.R., §§ 1508.7 and
1508.8).
The CWA and regulations for implementation of Sec. 404 by both EPA (40
C.F.R., Pan 230) and the USACE (33 U.S.C., Parts 320-330) require consideration of
cumulative impacts, but for a number of reasons (Horak et al. 1983) they are seldom
evaluated in permit review processes.
Conversion of bottomland hardwood forest to agriculture is a typical cumulative
impact. Historically the incremental clearing of 10 to as many as 2,000 ha in an individual
permit has been perceived to have no "significant" ecological impact on a total forest system
of several million hectares, and the cumulative effect of many such permitted activities has
been ignored (Louisiana Wildlife Federation v. York 1985). This failure can be understood
if the present regulatory process is contrasted with the kind of process required for
cumulative impact assessment.
The Sec. 404 permit process focuses on the impact of a proposed activity at an
individual wetland permit site. In contrast, cumulative impacts are landscape-level
phenomena that result from decisions at many individual permit sites (Gosselink and Lee
1987). Hence they are external to the focus of individual permit reviews. In addition the
current permit process is largely reactive; that is, the decision about whether or not to
permit an activity on a site is made in response to a permit request, not in advance of it. If
cumulative impacts are to be managed, decisions regarding individual sites will have to be
governed by earlier decisions made about the allowable extent of modification of the whole
landscape unit.
Thus, cumulative impact management has the potential to change current wetland
regulatory practices in two significant ways: (1) it raises the focus of management from
site-specific to natural landscape units; and (2) it imposes landscape planning on the current
Sec. 404 process, which is largely reactive. As noted earlier, EPA has authority for
planning under the Advance Identification provisions of the CWA (33 U.S.C. (b), §
1344(c); see also 40 C.F.R., §231.1 and § 230.80).
Gosselink and Lee (1987) described a three-part methodology for cumulative
impact assessment and management that incorporates both planning and a landscape-level
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focus: (1) assessment, the characterization of cumulative effects on both ecological
structure and functional ecological processes in a designated landscape unit; (2) goal
setting, agreement by public consensus on environmental goals for the assessment area,
based on the assessment; and (3) implementation, the development of specific plans to
implement the goals based on the landscape structure and function of the assessment area.
The landscape-scale requirement of cumulative impact management is addressed by
choosing boundaries for the assessment unit that encompass an area that is, to the extent
possible, ecologically closed to water and nutrient flows (so that sources external to the
basin can be minimized) and also large enough to satisfy the home range and habitat
requirements of the farthest-ranging animal species of interest (this might be, for example,
the black bear or the Florida panther). The latter requirement ensures that a diverse group
of biota having smaller ranges will also be encompassed in the analysis. The choice of
boundaries is also influenced by such pragmatic considerations as political jurisdiction and
map scales. Gosselink and Lee (1987) recommend boundaries that enclose 1 million ha or
more and that are natural hydrologic watersheds or drainage basins.
To characterize an area this large, the proposed cumulative impact assessment
methodology focuses on a limited number of "landscape indices" that reflect ecological
structure and hydrologic, water quality, and biotic functions. By "landscape indices" we
mean simple, measurable properties that integrate ecological processes over large areas.
For example, a stream water quality record reflects water chemistry conditions in the
watershed above the sample station. Use of long-term data records allows a time-series
analysis of system change.
Landscape Ecology and Natural Resource Conservation
Troll (1950) defined landscape ecology as the study of the physicobiological
relationships that govern the different spatial units of a region. It is that branch of ecology
that deals with large areas and the interaction of parts within these areas. Thus, the
emphasis is on the pattern of the landscape and how pattern influences ecological processes
or functions. Of particular interest in this discussion of cumulative impacts is the study of
island biogeography, a field pioneered by MacArthur and Wilson (1967), and the
application of that knowledge to the design of ecological preserves (Diamond 1975). These
studies are concerned with the size and shape of patches in the landscape, their isolation
from each other, and the influence of these factors on species diversity. Whereas in the
pioneering studies .the patches were islands isolated by water, in applications to natural
preserves the patches studied were forests isolated by grasslands, agricultural fields, or
other human barriers. Diamond (1975) summarized five landscape principles for natural
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reserves: (1) species richness increases with forest area; (2) for a given total forest area,
one large reserve will support more native interior species than two or more smaller ones;
(3) for a given forest area, close disjunct patches will support more species than patches
farther apart; (4) disjunct forest patches connected by strips of protected habitat are
preferable to isolated patches (protected corridors facilitate animal movement between
patches and provide gradual ecotones between similar habitat types); and (5) other things
being equal, a circular-shaped reserve is preferable to a linear one because the former
maximizes dispersal distances within the reserve and minimizes the edge relative to the
interior.
Landscape ecology focuses attention on the interaction of parts in a pattern that
constitues a unified whole. For resource management this means that wetlands cannot be
effectively managed in isolation. They are integral parts of the total landscape, influenced
by upstream and upslope events, and influencing downstream ecosystem components.
Therefore, wedand cumulative impact assessment, as described by Gosselink and Lee
(1987), generally includes an entire drainage unit, without regard to how much of it is
jurisdictional wedand. While subsequent management may, of regulatory necessity, focus
more closely on wetlands, the problems must be understood in a broader context to be
effectively managed.
PURPOSE OF THE STUDY
This report is an ecological characterization of the Pearl River basin. The
characterization is a historical description of the natural renewable resources of the basin
and an assessment of the cumulative effects of any human activites on those resources.
The study follows, in general, the methodology of Gosselink and Lee (1987). Specifically
the objectives are to
1.	describe the structure (land use, land cover) of the basin and its changes
through time.
2.	describe the ecological processes of the basin and their changes through
time, specifically regarding hydrology, water quality, and biota.
3.	describe the relationship between structural and functional elements of the
basin.
4.	describe human activities in the basin and their impact on ecological structure
and function.
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PEARL RIVER BASIN: GENERAL DESCRIPTION
Location and Size
The Pearl River basin lies within the East Gulf Coastal Plain of Mississippi and
Louisiana, and drains an area of 22,688 km2. Ninety percent comprises all or parts of 23
counties in Mississippi; the remainder is in parts of three parishes in southeastern Louisiana
(U.S. Fish and Wildlife Service 1981). The basin is 386 km long and ranges in width
from approximately 10 km near the Gulf of Mexico to 80 km farther upstream (US ACE
1970) (Figure 1-1). The offshore boundary of the basin follows U.S. 90 west to the
Intracoastal Waterway, then south along the Mississippi River Gulf Outlet (MRGO) to the
Chandeleur Island chain. The study area then follows the outer edge of the Chandeleur
Islands northeast to the Mississippi-Louisiana boundary, back northwest, and finally
angles across Mississippi Sound to include marshes east of the mouth of the East Pearl
River (Figure 1-2).
The Pearl, one of Mississippi's major rivers, is formed by the confluence of the
Tallahaga and Nanawaya creeks in Neshoba County. From its headwaters to the formation
of the East and West Pearl rivers west of Picayune, Mississippi, the river flows
approximately 629 km, dividing at this point into two separate drainage systems. The East
and West Pearl flow for 77 and 71 km, respectively, and empty into Lake Borgne,
Mississippi Sound, and the Rigolets, arms of the Gulf of Mexico. Most of the low-water
flow of the East Pearl flows into the West Pearl approximately 47 km above the mouth
(USACE 1970).
The Pearl's principal headwater tributaries are the Yockanookany River and
Lobutcha and Tuscalameta creeks. The Strong River in the middle reach and the Bogue
Chitto in the lower are the only other major tributaries (Figure 1-1). The basin can be
divided hydrologically into the following nine subunits: Upper Pearl River, Yockanookany
River, Pelahatchie Creek, Tuscalameta Creek, Richland Creek, Strong River, Middle Pearl
River, Bogue Chitto River, and Lower Pearl River (from north to south) (U.S. Geological
Survey 1976) (Figure 1-3).
Much of the Pearl River has remained relatively undisturbed. The Louisiana
legislature included the entire West Pearl River in the state natural and scenic rivers system,
attesting to the biological value of the area (Office of State Planning, personal
communication).
There are numerous small lakes in the basin. The only large lake is the Ross Barnett
Reservoir, constructed by the Pearl River Valley Water Supply District in 1964 to provide
municipal and industrial water supply and recreation. Located along the Pearl River just
above Jackson, the reservoir is 29 km long and averages 4 km in width (USFWS 1981).
8

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Rc»8 Barnttt
R«»ervoir
Alabama
rrt*
if MISS.



i M
«
) w

/ 4


J
0	10 20 30 40	.
1	i i i i Kilom«U«
Lek* Pontchartnin
Miititsippi Sound
LaktBorftn*	Figure 1-1.
Location map of
of the Pearl River
basin inshore area.
9

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0	10 20 so Xilomttar*
	1	i	' ¦ ¦ ' «

^ S


-vV
t/.f li • •
i ^
-El,
N
f
Vi
u-
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&
t*~ i—
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«=/


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Richland
Sub-Basin
Yockanookany
Sub-Basin
Pelahatchie
Sub-Basin
( ocktnook
'River
Upper Pearl
Sub-Basin
Strong River
Tuscalameta
Sub-Basin
Middle Pearl
Sub-Basin
Mississippi
Louisiana
Bogue Chitio
Sub-Basin
Bogue Chitio
River

1 River
Lower Pearl
Sub-Basin
Riven
Sub unit boundaries
0	10 20 30 40 Kilometers
	1	I	I	I	I
Figure 1 -3. Hydrologic sub-basins of the Pearl River study area.
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Climate
The climate of the Pearl River basin is determined principally by the huge
continental land mass to the north, the subtropical latitude, and the Gulf of Mexico to the
south. The resultant long, hot summers, mild winters, and heavy rainfall are typical of the
humid subtropics. Annual precipitation in the coastal area averages approximately 163 cm;
the north-central portion receives approximately 132 cm per year (USFWS 1981). Mean
average annual temperature varies from 18° C in the northern portion of the basin to 19° C
in the south. Mean average July temperature is 27° C north and south (USACE 1970).
Landforms and Vegetation
The East Gulf Coastal Plain within which the basin lies is physiographically divided
into the North Central Plateau, Jackson Prairie, Southern Pine Hills, and Coastal Pine
Meadows districts (Figure 1-4). Elevations range from sea level in Coastal Pine Meadows
to nearly 198 m in the North Central Plateau (USACE 1970).
The North Central Plateau can be divided into a wide upland area on the north, cut
by streams into hills and valleys, and a narrower belt to the south called the Buhrstone
Cuesta. Sandy formations underlie the surface at various locations, absorbing and storing
large amounts of groundwater. The North Central Hills gradually descend into the gently
rolling country of the Jackson Prairie, a relatively narrow belt with numerous prairie-like
tracts containing excellent farmland. The relatively smooth topography results from the
weathering of clayey formations. The red and yellow clay uplands of the North Central
Plateau and Jackson Prairie support stands of mixed hardwoods and loblolly and short-leaf
pine; gums, oaks, and hickory characterize the lowlands (USACE 1970).
South of Jackson Prairie lie the sloping uplands of the Southern Pine Hills. This
region is underlain mainly by sandy, porous soils noteworthy for their capacity for storing
large volumes of rainwater, which maintain the substantial flows of the streams in the basin
below Jackson. The larger tributaries of the Pearl cross this upland in wide, flat-bottomed
valleys with 30- to 90-m-deep slopes (USACE 1970). The Southern Pine Hills formerly
supported dense stands of slash and long-leaf pine; however, most of this has been cut for
timber. Reforestation with conifers and some hardwood cultivation are currently major
activities.
Coastal Pine Meadows is a low-lying, district that borders Mississippi Sound, Lake
Borgne, and Lake Pontchartrain. The landscape, generally flat with large tracts of swamp
and marsh, supports mosdy long-leaf and slash pine in the higher portions (USACE 1970);
bottomland hardwood forests of oaks, bald cypress, tupelo, etc., in the low-lying
elevations; and freshwater to brackish marshes nearer the coast.
12

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«
PINE MEADOWS-^Sl

Figure 1 -4. Physiographic regions of the Pearl River basin (from USACE 1970).
13

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EXPLANATION
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aidat Ms	fcnwatO lUMinNly |m«(ff 6«di U U« wutA £>*¦
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-------
Geology and Soils
Geologically the basin is not a contained unit because formations extend beyond
topographic divides into adjoining stream basins (USACE 1970). At the surface,
formations are sedimentary and range from Eocene to Recent They dip southwestward
throughout the northern three-fourths of the basin except where interrupted by structural
features such as the Jackson Dome and other smaller salt domes. In the southern portion
the rate of dip becomes steep as a result of pronounced downwarping toward the
Mississippi River structural trough (USACE 1970). Figure 1-5 illustrates geologic features
of the Pearl River basin.
Sand and clay constitute most of the sedimentary deposits extending from the
northern portion of the basin to the coast; marl, limestone, and glauconitic and lignitdc
material are also present in several locations. The low natural fertility of the forest soils that
generally characterize the basin offsets the effects of the basin's highly productive climate
(USACE 1970).
Socioeconomic Development
The basin was divided into Upper, Middle, and Lower Pearl subareas to facilitate
socioeconomic analysis. These regions reflect groups of counties/parishes strongly related
by watershed factors, water needs, geographical characteristics, and economic activity
(Figure 1-6).
Population
Total population of the basin increased from 127,000 in 1870 to 420,200 in 1930,
and 845,000 in 1970. More recent population trends indicate a large increase in population
in the 1970s to slightly over 1 million in 1980 (U.S. Bureau of the Census 1940-1980)
(Figure 1-7). The urban population more than tripled from 1930 to 1960, increasing from
102,500 to 308,900. Of the urban population increase during this period, 51% resulted
from growth at Jackson, the largest urban center in the basin. Rural nonfarm population
increased 184% from 75,700 in 1930 to 214,900 in 1970. Rural farm population during
this period decreased from 242,000 to 67,000, reflecting the national trend of migration
from rural areas to urban centers and their environs (USACE 1970).
Historically, the population size of the Pearl River basin has fluctuated, except in the
lowermost portion, where sustained growth has occurred since 1870. The agriculture-
dependent Middle Pearl subarea contained nearly one-half of the basin's population in
15

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16

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1870, but only 31% in 1960. The Upper Pearl increased in population after 1920 until
1960; growth accelerated from about 1940.
Total population in the basin is projected to increase to 1,035,922 by 2020
(Maruggi and Fletes 1983; Mississippi Research and Development Center 1986;
Mississippi State University 1986). Urban population growth is expected to continue at a
faster rate than rural nonfarm. Rural farm populations are expected to continue to decline
(USACE 1970).
Employment
Once almost totally dependent on agriculture, the basin's economy is now in a
period of diversified manufacturing and nonagricuiture/nonmant,factoring activity (Figure
1-8). Manufacturing employment increased from 22% in 1960 to 38% in 1985. By 2020,
employment in manufacturing is expected to increase to about 213% over that of 1970.
Clothing, lumber, wood, furniture, pulp and papers, and food-processing industries
provide the major part of employment in manufacturing (USACE 1970).
Although agriculture is still an important segment of the basin's economy, its
relative importance continues to decline as the economy becomes more diversified. The
number of farms decreased from 51,871 in 1939 to 26,773 in 1964, and is projected to
decrease to 14,543 by 2020 (USACE 1970). Principal crops are cotton, corn, oats,
soybeans, and hay. Livestock and livestock products (principally broilers and eggs) are an
integral part of the basin's agricultural economy and are expected to become more important
in the future (USACE 1970).
The area occupied by forests in the basin is considerably larger than the acreage
devoted to all other land uses. Forestry resources have fluctuated only moderately since
1930, and little change is expected in the future. The trend toward conversion of farmlands
to forests has tended to offset the effects of land clearing. Employment in timber-based
manufacturing industries in the basin has steadily increased, growing from 730 in 1930 to
3,800 in 1960. Employment is projected to be 12,000 in 2015 (USACE 1970). Much of
this increase is expected from pine plantings of open areas, inter- and underplantings, stand
conversion, and better management of forest land. A variety of sawmills, wood preserving
plants, veneer plants, and other wood processing industries are located throughout the
basin.
Labor Force and Income
The labor force of the upper subarea of the Pearl River basin increased about 60%
during 1930-1960 (USACE 1970), mainly because of the development of Jackson as a
17

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Percent Change
	r 30
-20
-10
1940-50 1950-60 1960-70 1970-80
Population
1970 1980
Figure 1-7. Population trends for the Pearl River basin (from U.S. Bureau of Census,
1940-80).
18

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Other
Public Admin.
Services
Fin, Ins, R. E.
Trades
Trn, Com, P U
Manufacturing
Construction
Mining
Ag, For & Fish


¦	% 1960
B	% 1970
@	% 1980
~	% 1985
Abbreviations:
Public Admin. = Public Administration,
Fin, Ins, R. E.» Finance, Insurance, & Real Estate,
Trn, Com, P U » Transportation, Communication, & Public Utilities,
Ag, For & Fish - Agriculture , Forest & Fish.
Figure 1 -8 Major sources of personal income during 1960-1985, by percentage, in the
Pearl River basin (from U.S. Bureau of Census 1960-1985).
19

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government-distribution-finance-service center. This subarea also has provided, and is
expected to continue to provide, the greatest personal income advances for the basin.
The labor force in the agriculture-dependent middle subarea declined from 40% of
the study area total in 1930 to 29% in 1960 (USACE 1970). Likewise, the rate of personal
income growth in the middle subarea has declined since 1940. Slow urban growth and
lack of diversified economic development are expected to continue to retard future income
growth in this area.
The labor force in the lower subarea is predicted to multiply more than tenfold
during 1960-2015 (USACE 1970), partly as a result of economic stimuli provided by the
National Aeronautics and Space Administration (NASA) facility near Slidell. Future
personal income growth in the lower subarea, located in the path of rapidly expanding
urban and tourist development between the Mississippi Gulf Coast and New Orleans,
should accelerate at a greater rate than it has in the past. (USACE 1970).
Protected Areas
Protected areas within the Pearl River basin are shown in Figure 1-9. Portions of
two national forests are located in the upper portion of the basin (Bienville and Tombigbee)
and are administered by the U.S. Forest Service for timber production and as habitat for
fish and wildlife species. The Bogue Chitto National Wildlife Refuge encompasses
approximately 40,000 acres of primarily bottomland hardwoods along the Pearl River in
Pearl River County, Mississippi, and St. Tammany and Washington Parishes, Louisiana.
Breton National Wildlife Refuge is located in the Chandeleur Islands.
State wildlife management areas in the basin include Bienville and Caney Creek in
the upper portion of Bienville National Forest; Dancing Waters and Choctaw in the
northeast portion; the Pearl River Waterfowl Refuge and Management Area adjacent to
Ross Barnett Reservoir in Madison County; Marion County Wildlife Management Area
(WMA); Wolf River WMA located in Marion, Lamar, and Pearl River counties (the largest
in the basin at 240,000 acres); the 40,000-acre Pearl River WMA in St Tammany Parish,
Louisiana; and the White Kitchen tract, recendy purchased by the Nature Conservancy.
Several Choctaw Indian reservations are located in the northern portion of the
basin. Three state parks are managed in the upper basin, one in the lower portion. The
Natchez Trace Parkway, administered by the National Park Service, runs through the
western portion of the upper and middle basin from the Choctaw-Attala county line to
Jackson. Coastal marshes encompass approximately 23,000 acres in Mississippi and
Louisiana. At present, none of the coastal marsh in the basin is in state or federal
ownership (USFWS 1981).
20

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TtNK
MISS.




«

n




Indian Reservation
State Park
State Wildlife Management area
National Wildlife Refuge
m National Forest
National Parte
~ White Kitchen Tract
0	10 20 30 40	,
1	i i i i Kilometers
Pearl River
Vhite Kitchen'
Figure 1-9. Protected areas within the Pearl River basin.
21

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Scenic Streams in Louisiana that are protected include Pushepatapa Creek, Bogue
Chitto River, and West Pearl River. Mississippi has no official designation; however,
portions of the Yockanookany River, Strong River, Bogue Chitto River, Magees Creek,
and West and East Hoboolochitto creeks, among others, have been proposed as wild and
scenic streams.
22

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REFERENCES
Abernethy, Y., and R. E. Turner 1987. U.S. forested wetlands: 1940-1980. Bioscience
37(10):721-727.
Avoyelles Sportmen's League v. Marsh. 1983. 715 F.2d 897,903 n. 12, 5th Cir.
Clean Water Act, Section 404(f) (33 U.S.C. § 1344(f) (2)); 33C.F.R. § 323.4 (a) (1) (iii)
(c) (2); 40 C.F.R. § 232. 1988. Sec. 404 program definitions: exempt activities
not requiring 404 permits. Federal Register, Vol. 53, No. 108, 20764-20776.
Diamond, J. M. 1975. The island dilemma: lessons of modern biogeographic studies for
the design of natural reserves. Biological Conservation 7:129-146.
Gosselink, J. G., and L. C. Lee. 1987. Cumulative impact assessment in bottomland
hardwood forests. LSU-CEI-86-09. Center for Wetland Resources, Louisiana
State University, Baton Rouge.
Horak, G. C., E. C. Vlachos, and E. W. Cline. 1983. Fish and wildlife and cumulative
impacts: is there a problem? Prepared for Eastern Energy and Land Use Team,
U.S. Fish and Wildlife Service, by Dynamac Corp., Fort Collins, Colo.
Lee, L. C. and J. G. Gosselink. 1988. Cumulative impacts on wetlands: linking
scientific assessments and regulatory alternatives. Environmental Management
12:591-602.
Louisiana Wildlife Federation v. York. 1985. 761 F. 2d 10044, 5th Cir.
MacArthur, R. H., and E. O. Wilson. 1967. The theory of island biogeography.
Evolution 17:373-387.
Maruggi, V., and R. Fletes. 1983. Population projections to 2000 for Louisiana and its
planning districts, metropolitan areas, and parishes. Series II Report. University
of New Orleans and Louisiana State Planning Office.
Mississippi Research and Development Center. 1986. Handbook of selected data for
Mississippi. Mississippi Research and Development Center, Jackson, Miss.
Mississippi State University, College of Business and Industry. 1986. Mississippi
statistical abstract. Mississippi State.
23

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National Wetlands Newsletter. Mar/Apr. 1984. Re: settlement of National Wildlife
Federation v. Marsh suit.
Natural Resources Law Institute. 1988. A guide to federal wetlands protection under
Section 404 of the Clean Water Act. Anadromous fish law memo 46. Lewis and
Clark Law School, Portland, Oregon.
Troll, C. 1950. Die geographische Landschaft und ihre Erforschung. Studium General
3:163-181.
U.S. Army Corps of Engineers. 1970. Pearl River comprehensive basin study. Vols 1-7.
U.S. Department of the Interior, Federal Water Quality Administration, Atlanta,
Ga
U.S. Bureau of Census. 1940-1980. Census of population. U.S. Department of
Commerce, Washington, D.C.
U.S. Bureau of Census. 1960-1985. County business patterns. U.S. Department of
Commerce, Washington, D.C.
U.S. Fish and Wildlife Service. 1981. A resource inventory of the Pearl River basin,
Mississippi and Louisiana. U.S. Department of the Interior, Fish and Wildlife
Service, Ecological Services, Decatur, Ala.
U.S. Geological Survey. 1972. Map showing effect of geology on minimum streamflow
and water quality, Pearl River basin. Water Supply Paper 1899-M, Plate 2.
U.S. Geological Survey. 1976. Hydrologic unit map. State of Mississippi, 1974. U.S.
Geological Survey, Reston, Va.
U.S. w.Holland. 1974. 373 F. Supp. 665. M.D. Fla.; NRDC v. Callaway. 1975. 392
F. Supp. 685. D.D.C.
24

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CHAPTER 2: LAND USE IN THE PEARL RIVER BASIN
25

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/

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INTRODUCTION
The ecological functions and values of a landscape are related to a large degree to its
land use characteristics. The biotic communities supported and the water quality and flow
characteristics of rivers and streams all can vary depending upon the ratios of the different
land uses practiced in the region.
This chapter, which describes land cover and use characteristics of the Pearl River
basin, is one of four basic units of the overall cumulative impact assessment of the Pearl
River basin. The goal of the chapter is to assess the historical land uses of the Pearl River
basin, document its recent (1987) land use characteristics, and present these data within a
framework that allows the investigation of relationships between land use practices and
their cumulative environmental effect on the basin's water quality, hydrology, and biota.
METHODS
Description of the Study Area
The Pearl River basin is located in south-central Mississippi and a small part of
extreme southeastern Louisiana (Figure 2-1). The Pearl River flows generally from north
to south for about 640 km to the Gulf of Mexico, draining an area of about 2.3 million ha
along its course.
The Pearl River is typical of many streams in the southeastern United States; its low
stream gradient and broad, flat flood plain produces extensive meanders, natural cutoffs,
oxbow lakes, and overflow channels. The flood plain is largely forested with bottomland
hardwoods, bald cypress, and tupelo gum. Unlike most rivers and streams in the
Southeast, the Pearl has escaped extensive modification. What little development has
occurred is in towns and cities along the river, especially in the Jackson and Slidell areas.
The major tributaries of the Pearl River, whose watersheds form subunits (sub-
basins) of the study area, include Lobutcha Creek, Tuscalameta Creek, Yockanookany
River, Strong River, Bogue Chitto River, Richland Creek, and Pelahatchie Creek.
The inshore portion of the study area is bounded on the north by the Tombigbee
River basin (USGS hydrologic unit number 0316), on the east by the Pascagoula River
basin (0317), and on the west by the Mississippi River basin (0804) and several small
streams that drain into Lake Ponchartrain in Louisiana. On the south the offshore area
influenced by discharge from the Pearl River is poorly defined. For this study we included
parts of Mississippi Sound and Lake Borgne and defined the boundaries as follows: U.S.
90 West from the land boundary of the West Pearl River to the Intracoastal Waterway, then
south along the Mississippi River Gulf Outlet (MRGO) to the Chandeleur Islands, the outer
27

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Ross B«rn*tt
Reservoir
Alabama

MISS.




4

«




0	10 20 30 40
	1	I	' ¦ ¦
Kilometers
Mississippi Sound
Lake Pontctortrain
Lake Borgne
Figure 2-1. Location map of the Pearl River basin.
28

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edge of the Chandeleur Island chain northeast to the Mississippi-Louisiana boundary, then
northwest across Mississippi Sound to the mouth of the East Pearl River (Figure 2-2).
Inshore Study Area
Land Use Mapping
All land use mapping and analyses of digital, spatial land cover data for the inshore
zone were performed by the Mississippi Automated Resources Information System
(MARIS). The 1973 land use information was obtained from an existing MARIS digital
data base covering the study area. In the 1973 study land use had been manually
interpreted directly from high-altitude color infrared aerial photography scaled at
1:120,000, then plotted on a film base at 1:24,000 scale. Data were digitized and originally
gridded into 50m x 50m cells, then generalized into 250m x 250m cells for this study.
Landsat-MSS images from a December 1987 overpass covering the study area were
machine classified. Classification judgments were made using 1987 color infrared (CER)
aerial photographs at a scale of 1:60,000 to confirm the machine classification. Data were
stored in 250m x 250m grid cells (6.25 ha/cell) in a geographic information system (GIS)
established for this study.
The following 10 land use categories were mapped for both data bases:
Agriculture
Coniferous Forest
Deciduous Forest
Mixed Forest
Bottomland Hardwood Forest
Forested Wetland (Swamp)
Non-forested Wetland
Urban
Water
Other
any area of cropland, pasture, or grassland
>	80% pine species
>	80% non-pine species
mix of pine and non-pine; neither >80%
described below
forest with standing water
marsh
In the 1973 land use data base, bottomland hardwood (BLH) forests were defined
by overlaying county flood maps produced by the U.S. Department of Housing and Urban
Development (HUD). Bottomland hardwood forests were those areas within which
deciduous forests overlapped the flood zone.
29

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30

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Bottomland hardwood forests were distinguished in two ways in the 1987 data
.base: (1) areas of deciduous forest located exclusively on river bottoms were classified
directly from the Landsat imagery, and (2) deciduous forest coinciding with overlaid
hydric soils were further classified as BLH forests.
Historical Land Use Data
Historical data on forest and agricultural land use by county in the Pearl River basin
were obtained from the U.S. Forest Service (USFS) and U.S. Department of Ariculture
(USDA).
Forest Patch Analysis
Size and frequency of forest patches within the Pearl River basin in 1987 were
determined for each sub-basin. Forest categories included in the analysis were coniferous,
deciduous, mixed, bottomland hardwood, swamp, and total forest.
Stream Edge Habitat
Land uses within a 250-m strip bordering each stream edge of the nine major
tributaries and subregions of the Pearl River were determined from the 1987 land use data
base.
Offshore Study Area
Land use characteristics of the offshore portion of the study area were determined
from the U.S. Fish and Wildlife Services (USFWS) 1956 and 1978 digital data bases
(Wicker 1980), accessed through the Louisiana Department of Natural Resources, Coastal
Management Division (CMD). The data for 1956 were based on interpretations of black-
and-white photographs, and the data for for 1978 on color infrared photographs. Land use
statistics were generated by CMD for the offshore study area for both 1956 and 1978, and
land use change maps were determined for that interval.
RESULTS
Inshore Study Area
Historical Land Cover Trends
USDA data indicate that the area of agricultural land in the Pearl River basin has
remained fairly constant since 1935. In 1935 about 648,000 ha were used for agriculture
and pastureland, about the same as in 1985 (Figure 2-3). Likewise, the areas of upland
forest (1.2 million ha) and of wetland forest (240,000 ha) have remained fairly constant
since the 1960s (Figure 2- 3).
31

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AREA OF AGRICULTURE IN THE PEARL RIVER BASIN
1400
8
X
1930 1940 1950 1960 1970 1980 1990
Year
AREA OF NON-WETLAND FOREST IN THE PEARL RIVER
1400
I
8
1960
1970
1980
1990
Year
AREA OF WETLAND FOREST IN THE PEARL RIVER BASIN
1400
8
X
1 960
1970
1980
1990
Year
Figure 2-3. Area of agriculture and forested land in the Pearl River basin between
1930 and 1985 (USFS, USDA).
32

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In 1973 the Pearl River basin was 61% forested, of which about 49% was upland
forest. Coniferous forest made up 26% of the basin; deciduous and mixed, 23%;
bottomland hardwoods, 10%; and swamp forest, 3%. Agriculture and grassland made up
about 33% of the basin's land area; urban area, about 3%; and water, nonforested wetland
(marsh), and a miscellaneous category combined, a total of less than 3% (Figure 2-4).
Land use statistics from the 1987 data base are similar to those for 1973. Total
forest cover of the entire basin had increased slighdy to about 64%; about 52% of this was
upland forest. Included within the total forest cover were coniferous, 29%; deciduous and
mixed, 23%; bottomland hardwoods, 7%; and swamp forest, 4% (Figure 2-4).
Figures 2-5 through 2-13 present 1973 and 1987 land use statistics for each of the
nine sub-basins of the study area. As seen on the land use maps (Figures 2-14, 2-15),
forest and-agriculture are interspersed throughout the basin, with rather minor variation
from one sub-basin to another.
Agricultural land use decreased in seven of the nine sub-basins. Only in the two
southernmost sub-basins did agricultural land use increase. Coniferous forest cover
increased in six of the nine sub-basins; it decreased in Pelahatchie, Richland Creek, and
Strong sub-basins. Cover by mixed deciduous forests increased in four of the nine sub-
basins, all in the upper basin.
Wedands covered from 8% to 19% of the area within the sub-basins. Most of the
approximately 20,000 ha lost between 1973 and 1987 in the Pearl River basin were in the
northernmost four sub-basins. Overall, loss rates during 1973-1987 ranged from 1% in
the Lower Pearl to 4% in the Upper Pearl and Tuscalameta Creek sub-basins.
Stream Edge Habitat
Land cover adjacent to the stream edges of the Pearl River and its major tributaries
was calculated from the 1987 data base. Of the strip within 250 m of the edges of these
streams 85% was forested; 65% of the stream edge "buffer" was covered by BLH or
swamp forest (21% swamp, 43% BLH). An additional 10% of this land was in
agriculture, 3% urban, 2% marsh, and less than 1% other (Figure 2-16).
Figure 2-17 includes percentages of land use categories within the stream-edge
buffer for all nine tributaries and subregions of the Pearl River. Areas of agricultural land
adjacent to streams varied from a low of 3% along Pelahatchie Creek to 22% along the
Bogue Chitto River. Upland forest stream edge varied from about 7% along the Lower
Pearl River to about 28% along the Bogue Chitto River. Wetland forest edge varied from
about 43% along the Bogue Chitto River to 78% edging the Upper Pearl River. In the
33

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
0	2000 4000 6000 8000 km
PEARL RIVER BASIN
973
1987
1973
1987
Agriculture/grassland	EZ3 Bottomland Forest, Forested Wetland
Coniferous Forest	I	I Nonforested Wetland
Mixed, Deciduous Forest	ES Water, Barren/other, Urban area
Figure 2-4. Land use in the Pearl River basin, 1973 and 1987.
34

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
YOCKANOOKANY RIVER
0 1973
¦ 1987

'////////////////S
'SSS/S///SSS/S/S///S/SS/SS///S///S
'//////////////////////////////////
T
"T
100 200
—I—
300
400
—I—
500
600 km
2%
25%
1973
30%
31%
1987
21%
36%
Agriculture/grassland
Coniferous Forest
Mixed, Deciduous Forest
Y/7/A Bottomland Forest, Forested Wetland
KS Water, Barren/other, Urban area
Figure 2-5. Area and percentage of total sub-basin area for each land use category in the
Yockanookany River sub-basin in 1973 and 1987.
35

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
UPPER PEARL RIVER
H 1973
¦ 1987

/////////////////////-
//////////////////////////////////
500
1000
1500
2000 km
1973
1987
¦I Agriculture/grassland	V///X Bottomland Forest, Forested Wetland
Coniferous Forest	Water, Barren/other, Urban are*
Mixed, Deciduous Foresi
Figure 2-6. Area and percentage of total sub-basin area for each land use category in the
Upper Pearl River sub-basin in 1973 and 1987.
36

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
TUSCALAMETA CREEK
H 1973
¦ 1987
—i	1	1—
100 200
300
—i—
400
—I—
500
600 km
14%
22%
¦I Agriculture/grassland
E2223 Coniferous Forest
HIH Mixed, Deciduous Forest
12222 Bottomland Forest, Forested Wetland
Water, Barren/other, Urban area
Figure 2-7. Area and percentage of total sub-basin area for each land use category in the
Tuscalameta Creek sub-basin in 1973 and 1987.
37

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
PELAHATCHIE CREEK
Q 1973
¦ 1987
/////////////,

S///////////////////////S///////S/////
'/////////////////////////////////////////
—I—
100
200 300
—I—
400
500 600 km
1973
1987
15%
29%
18%
13%
24%
25%
Agriculture/grassland	V7/A Bottomland Forest, Forested Wetland
Coniferous Forest	KSJ Water, Barren/other, Urban area
Mixed, Deciduous Forest
Figure 2-8. Area and percentage of total sub-basin area for each land use category in
Pelahatchie Creek sub-basin in 1973 and 1987.
33

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Urban area
Nonforesied Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland

RICHLAND CREEK
973
987
/////////////////s
y////////////
'/////////////////////.
////////////////////////////////

—I	'—I—1	1	'—I	'	1	1	
100 200 300 400 500 600 km
1973
1987
11%
32%
12%
27%
15%
27%
Agriculture/grassland	V///A Bottomland Forest, Forested Wetland
Coniferous Forest	ES Water, Barren/other, Urban area
Mixed, Deciduous Forest
Figure 2-9. Area and percentage of total sub-basin area for each land use category in the
Richland Creek sub-basin in 1973 and 1987.
39

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Urban area
Nonforested Wetland .
Barren/other g
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
3
MIDDLE PEARL RIVER
B 1973
¦ 1987
//////////////////////
Agriculture/grassland
sao
500
—I—
1000
—I—
1500
2000 km
30%
1973
34%
1987
28%
25%
30%
31%
Agriculture/grassland
Coniferous Forest
Mixed, Deciduous Forest
V//A Bottomland Forest, Forested Wetland
KSJ Water, Barren/other, Urban area
Figure 2-10. Area and percentage of total sub-basin area for each land use category in the
Middle Pearl River sub-basin in 1973 and 1987.
AO

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
STRONG RIVER
B 1973
¦ 1987
////////////////.
wurtA
i
0
—I—
100
200
300
i
400
500 600 km
1973
1987
2%
10%
29%
27%
38%
1%
22%
27%
Agriculture/grassland
Coniferous Forest
2J Mixed, Deciduous Forest
££££1 Bottomland Forest, Forested Wetland
Water, Barren/other, Urban area
Figure 2-11. Area and percentage of total sub-basin area for each land use category in the
Strong River sub-basin in 1973 and 1987.
41

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
BOGUE CHITTO RIVER
B9 1973
¦ 1987
^am

///////////////////S/S//SS/////S////S/S/SS,
—i—
500
—I—
I 000
I—
I 500
2
2000 km
23%
16%
28%
Agriculture/grassland
Coniferous Forest
Mixed, Deciduous Forest
Bottomland Forest, Forested Wetland
ES Water, Barren/other, Urban area
Figure 2-12. Area and percentage of total sub-basin area for each land use category in the
Bogue Chitto River sub-basin in 1973 and 1987.
42

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Urban area
Nonforested Wetland
Barren /other
Water
Forested Wetland
Bottomland Hardwood Forest
Deciduous Forest
Mixed Forest
Coniferous Forest
Agriculture/ grassland
LOWER PEARL RIVER
Q 1973
¦ 1987

1
o
—i—
500
1000
1500
2000 km
1973
1987
Agriculture/grassland	V//A Bottomland Forest, Forested Wetland
Coniferous Forest	I I Nonforested Wetland
Mixed, Deciduous Forest	KSS Water, Barren/other, Urban area
Figure 2-13. Area and percentage of total sub-basin area for each land use category in the
Lower Pearl River sub-basin in 1973 and 1987.
43

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-JXtT-
MW*H*ITI CO
Figure 2-14. Land use map of the Pearl River basin, 1973.
(See Plate 1 in the back pocket.)
44

-------
Figure 2-15. Land use map of the Pearl River basin, 1987.
(See Plate 2 in the back pocket.)
45

-------
¦
Agriculture
B
Coniferous
B
Mixed Forest
m
Deciduous
~
BLH
~
Swamp

Urban
~
Other
~
Marsh
43%
Figure 2-16. Percentage of stream edge bordered by each land use class in the Pearl
River basin, 1987.
46

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Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
10	20
Percentage Agriculture
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
Percentage Bottomland Hardwood Forest
sj
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
Percentage Coniferous Forest
Percentage Deciduous Forest
Figure 2-17. Percentages of land use categories bordering stream edges of the nine
tributaries and subregions of the Pearl River .

-------
Lower Peart
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Peart
Yockanookany
10	20
Percentage Urban
Figure 2-17. Cont'd.

-------
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
4 6 8
Percentage Mixed Forest
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
Percentage Other
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Pearl
Yockanookany
20	40	60
Percentage Swamp
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Upper Peari
Yockanookany
1 0
Percentage Marsh
Figure 2-17. Cont'd.

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Lower Pearl, wetlands bordered approximately 85% of the stream edge, including about
15% marsh. In the Richland Creek sub-basin, 22% of the stream edge was developed.
Forest Patch Analysis
We calculated the sizes and frequency of forest patches within the Pearl River basin
in 1987. Categories included in the analysis were coniferous, deciduous, mixed,
bottomland hardwood, forested wetland, and total forest.
Most forest patches within a forest type (coniferous, deciduous, etc.) in the Pearl
River basin are small, less than 32 ha (Figures 2-18 through 2-22). The largest patch is a
46,000-ha swamp forest (forested wetland) in the Lower Pearl sub-basin.
However, rerunning the forest patch analysis combining all forest types produces a
different picture. There are many small patches, but the greatest areas covered by far are
included within only a few very large patches (Figure 2-23). This is true for all sub-
basins.
Offshore Study Area
Land Cover
In 1956, of the 413,000-ha offshore study area, 81,700 ha was marsh, 19%
brackish or saline, about 1% fresh marsh, 79% water, and the remaining 1% made up of
beach, shrub/scrub, spoil, swamp, forest, developed, or other (Table 2-1).
By 1978, marsh had declined by 14.6% to 69,700 ha. About 17% of the area was
nonfresh marsh, only a trace (< 1%) was fresh marsh, 82% was water, and the remaining
1% was beach, shrub/scrub, spoil, developed, or other (Table 2-1). Most of the marsh lost
had become open water.
DISCUSSION
Inshore Study Area
Historical Land Cover
Before European settlement, the completely forested Pearl River basin was
occupied by several groups of native Americans, but no direct evidence links these groups
to known Indian tribes (U.S. Army Corps of Engineers 1985). Even after European
settlement in other areas of the southeastern United States, the Pearl River basin was not
aggressively settled until after about 1830, when cotton and timber became the major
industries. The Pearl River provided an avenue of transportation of goods, and steamboats
used the river after about 1835. The U.S. Army Corps of Engineers (USACE) began
maintaining the stream channel in 1880 (USACE 1985) and conducted significant snagging
and maintenance operations to improve navigability (see Chapter 3, this report). The
50

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.^cP1

. rfso*5*^^
.AS V
^ V^e
•^eV~ <^°^°
«**
0°® ..<^° .W.\°
,<\v


r\PV
r\ X% . rY\1
-i;!o,^'.c!sV-^

~ oS^" r v>JV
A*

HP'

>-»¦>;>
C^

-------
TOTAL AREA WITHIN EACH PATCH SIZE	PATCH SIZE FREQUENCY
TYPE-FORESTED WETLAND	TYP&FORESTED WETLAND
a	b
AREAL UPPER LIMIT (ha)
Figure 2-19.
Forest patch size and frequency distribution for forested wetlands, 1987. The horizontal axis groups the patches by size
classes on an exponential scale (10^ -^, 10^, etc.). The height of each bar is porportional to the area within each size class
(a) or the number of patches within a size class (b), which is given below each bar.

-------
TOTAL AREA WITHIN EACH PATCH SIZE
TYPE-DECIDUOUS
SUB-BASIN
UPPER PFARL
YOCKANOOKANY
river
pelahatchie
CREEK
PATCH SIZE FREQUENCY
TYPE-DECIDUOUS
b
lower
pearl
AREAL UPPER LIMIT (ha)
Figure 2-20. Forest patch size and frequency distribution for deciduous forests, 1987. The horizontal axis groups the patches by size
classes on an exponential scale (10*-5, 10^, etc.). The height of each bar is porportional to the area within each size class
(a) or the number of patches within a size class (b), which is given below each bar.

-------
TOTAL AREA WITHIN EACH PATCH SIZE
TYPE-MIXED
a
PATCH SIZE FREQUENCY
TYPE-MIXED
b
SUB-BASIN
UPPER PEARL
YOCKANOOKANY
RIVER
Figure 2-21. Forest patch size and frequency distribution for mixed forests, 1987. The horizontal axis groups the patches by size
classes on an exponential scale (10^-^, 10^, etc.). The height of each bar is porportional to the area within each size class
(a) or the number of patches within a size class (b), which is given below each bar.

-------
TOTAL AREA WITHIN EACH PATCH SIZE
TYPE-CONIFEROUS
a
PATCH SIZE FREQUENCY
TYPE-CONIFEROUS
b
I
sun-nAsiN
UPPER PEARL
yockanookany/ a / a / fl / fl
RfVER	/	/	/	/
mmji / BJi.il / un.M / Mil i
PELAHATCHIE
CREEK
TUSCALAMETA
CREEK
<-n
LOWER
pearl
RICHLAND
CREEK
STRONG
RIVER
MIDDLE
PEARL
BOGUE
CHITTO
AREAL UPPER LIMIT (ha)
Figure 2-22. Forest patch size and frequency distribution for coniferous forests, 1987. The horizontal axis groups the patches by size
classes on an exponential scale (10^-5,10^, etc.). The height of each bar is porportional to the area within each size class
(a) or the number of patches within a size class (b), which is given below each bar.

-------
TOTAL AREA WITHIN EACH PATCH SIZE
TYPE-TOTAL FOREST
a
PATCH SIZE FREQUENCY
TYPE-TOTAL FOREST
b
SUB-BASIN
AREAL UPPER LIMIT (ha)
Figure 2-23. Forest patch size and frequency distribution for total forests, 1987. The horizontal axis groups the patches by size classes
on an exponential scale (10l5,10^, etc.). The height of each bar is porportional to the area within each size class (a) or
the number of patches within a size class (b), which is given below each bar.

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Table 2-1. Land use characteristics of the Pearl River basin offshore study area, 1956-1978.
Change	% Change
Category	1956	1978	1956-1978 1956-1978
(ha)	(ha)	(ha)
Water
327,842
339,559
11,717
4
Total marsh
81,670
69,745
-11,925
-15
Fresh marsh
3,458
754
-2,704
-78
Nonfresh marsh
78,212
68,991
-9,220
-12
Intermediate marsh
	
3,443
	
	
Brackish marsh
	
40,206
	
	
Saline marsh
	
25,343
	
	
Forest
285
294
9
3
Swamp forest
746
184
-563
-75
Shrub/scrub
8
1,036
1,028
12,758
Shrub/scrub(spoil)
20
1,428
1,408
6,996
Agriculture/pasture
4
13
9
209
Developed
473
1,162
689
145
Beach
1,097
618
-479
-44
Other
848
332
-516
-61
Totals
412,994
414,371


57

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development of rail transportation caused a decline in river use, and maintenance by the
USACE was abandoned in the early 1900s (USACE 1985).
The earliest statistical records indicate that the area of land under cultivation or used
for pasture fluctuated somewhat from 1930 to 1985, but overall remained fairly constant
(Figure 2-3). Certainly no massive conversion of forest to agriculture has occurred here,
as has been the case in many river basins of the southeastern United States (Gosselink et al.
1989).
Available forest area data cover only the last 30 years, but also show little change.
A small increase in non-wetland forest area is probably due to an increase in pine
plantations in the basin (see below) associated with the reversion of some agricultural fields
to forest. Area of wetland forest stayed about the same during the 30 years (Figure 2-3),
decreasing by about 10,000 ha over that period.
In 1987, total forest cover in the Pearl River basin was about 64%; about 33% of
the basin was in agricultural land (Figure 2-4). About 52% of the forest cover was upland
forest, and 12% wetland forest.
Only relatively small changes in land use occurred over the basin as a whole during
1973-1987. The largest change was a 4% increase in upland forest and an approximately
2% decrease in agricultural land use. Most of the increase in upland forest area was due to
an increase in coniferous forest, which is consistent with other reports of increasing
emphasis on pine plantations in the basin.
Sub-basin Trends
Although general land use trends from 1973 to 1987 across the Pearl River basin as
a whole changed little, the degree of land use change within individual sub-basins varied
more. Land use in several sub-basins changed fairly significantly, although none changed
nearly so drastically as reported in other areas of the country, such as the Tensas basin,
Louisiana, where large-scale clearing of bottomland hardwoods for agriculture took place
over the last several decades (Gosselink et al. 1989).
Figures 2-5 through 2-13 plot land use and percentage change statistics for each of
the nine sub-basins. The results for several are noteworthy. The Bogue Chitto sub-basin
has the highest percentage of land area in agriculture, 45% in 1987, and it is one of only
two sub-basins in which area of agriculture increased between 1973 and 1987 (5%
increase). In the Lower Pearl sub-basin, agricultural land use increased slighdy Oess than
1%) over the interval. The Bogue Chitto sub-basin is also one of two sub-basins where
total forested area .decreased between 1973 and 1987, from 56% to 53% . Forested area in
the Strong River sub-basin decreased from 71% to 69% . It should be emphasized that
58

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these percentage changes in agriculture and forest areas are relatively small, especially
compared to other river basins around the country. They do, however, indicate some
differences in land use practices within the Pearl River basin.
The Richland Creek sub-basin, located in the Jackson, Mississippi, area is the only
sub-basin with significant urban land use, around 20% in both 1973 and 1987.
Interestingly, even in this more developed sub-basin, forest area increased by 6% from
1973 to 1987 (from 48% to 54% of the area).
Stream Edge Habitat
Land in the 250-m strip adjacent to the stream edges of the Pearl River and its
tributaries was mostly forested. Over the whole basin, 85% of the stream edge was forest;
65% of this was classified as swamp and BLH (Figure 2-16).
Individual sub-basins differed somewhat in land use along stream edges (Figure 2-
17). The Upper Pearl River's edges, for example, are only about 7% agricultural and 93%
forested; 78% are swamp and BLR The Bogue Chitto River in the middle basin has more
agricultural land use along the stream edges; 22% is agricultural land use and 72% forest,
of which 43% is swamp and BLH. In general the middle portion of the basin (Richland
Creek, Strong River, Middle Pearl, and Bogue Chitto River) has more agricultural land
along the stream edges and somewhat less swamp and BLH than the upper and lower
regions, though this relationship is not a strong one. The Yockanookany River in the
upper basin, unlike other watersheds in that region (Upper Pearl, Tuscalameta Creek, and
Pelahatchie Creek), has 12% agricultural use along its edges, about the same as the average
for the middle section.
"Forested stream edge is positively correlated with water quality (Lowrance et al.
1983; Peteijohn and Correll 1984), and functions as corridors for wildlife, connecting
forest patches. The exact relationship between the percentage of forest-bordered streams
and water quality has not been defined" (Gosselink and Lee 1989). However, the
percentage of stream edges bordered by forest in the Pearl River basin is probably high
compared to most rivers in the southeastern United States of equal size, and this fact should
be reflected in generally high quality water in the basin.
Forest Patch Analysis
Gosselink et al. (1989) made the following observations about the size, proximity
and continuity of forest patches and their relationships to animal and plant populations: the
diversity of native biota is closely related to both the size of forest patches, and
to their proximity and continuity through forested corridors (Diamond 1975; Soule
59

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and Simberloff 1986). Forest area is also positively related to healthy populations of
forest flora and fauna (Diamond 1975; Freemark and Mirriam 1986). In
particular, large patch size is critical for the survival of large mammals, raptors, and
other species typical of forest interiors (Soule and Wilcox 1980).
In the Pearl River basin, distribution of size classes of forest patches by forest type
includes many small and intermediate patches, and several very large patches (Figures 2-18
through 2-22). Since many forest types adjoin each other, the number of patches is
overestimated in this analysis. Treating each forest type (coniferous, BLH, etc.)
separately results in the maximum apparent fragmentation.
We also analyzed forest patch distribution by combining all forest types. In every
sub-basin most of the forested area is included in only a few patches (Figure 2-23). Each
basin has many small patches; however, the total area covered by small patches is small
relative to the few large ones. Large patches of forest occur in every sub-basin. The
Lower and the Upper Pearl have the largest single forest patches, both in excess of
240,000 ha.
In general, coniferous patches tend to be large and concentrated in the very northern
and southern parts of the basin, with very few in the middle section. Mixed and deciduous
forests constitute many small patches scattered fairly uniformly throughout the basin.
Bottomland forest (BLH and forested wetland) occurs in long, narrow patches bordering
streams. BLH generally occurs more commonly in the upper reaches of the basin; the
swamp (forested wetland) occurs more in the Lower Pearl, below Bogalusa. The largest
patch in the basin is a 46,000-ha swamp forest in the Lower Pearl sub-basin. Other large
BLH patches are located in the Strong River and Pelahatchie sub-basins.
Offshore Study Area
The size of the offshore area influenced by discharge from the Pearl River is not
well documented. For this study we rather arbitrarily defined the offshore region as
encompassing the coastal marshes south of the mouths of the Pearl River, adjacent to Lake
Borgne, south to the MRGO, and east to the Chandeleur Islands. This region covers about
413,000 ha, most of which is open water.
The best land use information available covering this area is the USFWS 1956 and
1978 digital data base (Wicker 1980); 1988 land use coverage is currently being processed
by the USFWS, but is not yet available. The region has two dominant land use categories,
open water and nonfresh marsh. In 1956, open water covered 79% of the area, and
nonfresh marsh, 19%. In 1978, open water covered 82%, and nonfresh marsh, 17%.
60

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Site-specific changes during 1956-1978 included the change of 12,384 ha of marsh
to open water (Table 2-2). Since significant addition of sediments can slow down or
reverse loss of marsh to water, we might expect a gradient of low marsh loss to higher loss
with increasing distance from the Pearl River's mouth, if the influence of sediments
discharged from the Pearl River extends into the marshes of the offshore study area. A
fairly uniform distribution of areas of marsh loss to open water across the study area is
apparent from visual inspection of the plotted maps.
Other land use changes within the offshore study area include the slow, landward
erosion and migration of the Chandeleur Islands. These islands are important to the region
because they provide some degree of protection to the coastal marshes from wave erosion
generated by the prevailing southeasterly winds, and probably more importantly from the
occasional tropical storms that pound the area.
61

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Table 2-2. Site-specific change detection, 1956-1978, for the Pearl River basin offshore
study area.
Change in Categories	Change	% Change*
1956-1978	(ha)	1956-1978
Water to water
243,390
78.53
Marsh to water
12,384
3.00
Land to water
1,504
0.36
Water to marsh
2,861
0.69
Marsh to marsh
66,017
15.99
Land to marsh
862
0.21
Water to land
649
0.16
Marsh to land
3,265
0.79
Land to land
1,116
0.27
* % Change = % of entire offshore study area.
62

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REFERENCES
Diamond, J. M. 1975. The island dilemma: lessons of modern biogeographic studies for
the design of nature reserves. Biological Conservation. 7:129-146.
Freemark, K. E., and H. G. Mirriam. 1986. Importance of area and habitat heterogeneity
to bird assemblages in temperate forest fragments. Biol. Conserv. 36:115-141.
Gosselink, J. G., G. P. Shaffer, L. C. Lee, D. M. Burdick, D. L. Childers, N. Taylor, S.
Hamilton, R. Boumans, D. Cushman, S. Fields, M. Koch, and J. Visser.
1989. Cumulative impact assessment and management in a forested wetland
watershed in the Mississippi River Floodplain. LSU-CEI-90-02. Marine
Sciences Department and Coastal Ecology Institute, Louisiana State University,
Baton Rouge.
Lowrance, R. R., R. L. Todd, and L. E. Asmussen. 1983. Waterbome nutrient budgets
for the riparian zone of an agricultural watershed. Agricultural Economics and
Environment 10:371-384.
Peteijohn, W. T., and D. L. Correll. 1984. Nutrient dynamics in an agricultural
watershed: observations on the role of a riparian forest. Ecology 65(5): 1466-
1475.
Soule, M. E., and D. Simberloff. 1986. What do genetics and ecology tell us about the
design of nature reserves? Biological Conservation 35:19-40.
Soule, M. E., and B. Z. Wilcox, eds. 1980. Conservation biology: an ecological-
evolutionary perspective. Sinauer Associates, Sunderland, Mass.
U.S. Army Corps of Engineers. 1985. Pearl River basin interim report on flood control
and environmental impact statement Vol. 1, report and EIS. Mobile District,
Mobile, Ala.
Wicker, K. M. 1980. Mississippi deltaic plain region ecological characterization: a habitat
mapping study. A user's guide to the habitat maps. Coastal Resources Program,
Louisiana Department of Natural Resources, Baton Rouge.
63

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CHAPTER 3: HYDROLOGY OF THE PEARL RIVER BASIN
65

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INTRODUCTION
This chapter presents the results of the analysis of hydrologic data from the Pearl River
Basin. The data of interest included long-term (~50 year) records of precipitation, river
stages, and discharges. These data were analyzed to determine the long-term, seasonally
adjusted trends. The primary concern was how the hydrologic regime related to both
natural and human-induced factors. Thus the task had two major objectives: to determine
the secular trends (if any) in the records, and to identify the factors that may be controlling
these changes.
In addition to the precipitation, stage, and discharge time-series data, other ancillary
data were also analyzed. These included tabulation of river works projects that may have
impacted the basin and estimates of the impact of the Pearl River on the adjacent offshore
waters.
HYDROLOGY OF THE PEARL RIVER BASIN
The Basin
The Pearl River basin (Figure 3-1) has a drainage area of about 2.3 million hectares and
drains 23 counties in east-central and southern Mississippi and 3 parishes in southeastern
Louisiana. The basin is about 390 km long with a maximum width of about 80 km. The
river splits into two portions, the East Pearl River and the West Pearl River, approximately
72 km from its mouth. The East Pearl River enters into the coastal waters of the Gulf of
Mexico through Lake Borgne. The West Pearl, located in Louisiana, enters the coastal
waters through The Rigolets, a tidal pass of Lake Pontchartrain, and carries a majority of
the flow. The principal tributaries to the river are the Yockanookany River, in the northern
part of the basin, the Strong River in the middle part of the basin, and the Bogue Chitto in
the southern part of the basin. The river is also fed by numerous smaller tributaries
distributed throughout the basin. The lower 70 km of the river are influenced to some
extent by Gulf of Mexico tides via Mississippi Sound and Lake Borgne.
The relationship between drainage basin area and long-term (15+ years) discharge for
the basin is presented in Figure 3-2. Figure 3-3 presents the discharge as a function of
distance from the mouth of the river. The data presented in these figures indicate that the
runoff is uniformly distributed throughout the basin, so that flow gradually increases from
north to south. The runoff data (Figure 3-4), show an increase in runoff/unit surface area
from north to south within the basin. This is a reflection of the rainfall distribution
throughout the basin, which has greater rainfall in the southern parts than in the northern
parts This trend can be seen in Figure 3-5, which presents the mean yearly total
67

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3
Figure 3-1. Map of the Pearl River system, showing the drainage basin for the Pearl River
(shaded area), the climatological divisions for Mississippi (1-10), and selected
stage and discharge station locations (black dots).
63

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AREA (km 2)
Figure 3-2. Long-term annual discharge (cubic meters per second) as a function of
drainage area for stations in the Pearl River basin. Data from US ACE
(1970).
500
400
O
100	200	300
DISTANCE FROM MOUTH (km)
400
Figure 3-3. Long-term discharge (cubic meters per second) as a function of distance
(kilometers) from the mouth of the Pearl River. Data from US ACE (1970).
6n

-------
i	¦	1	—¦	r
100	200	300
DISTANCE FROM MOUTH (km)
400
Figure 3-4. Annual mean runoff (centimeters) per unit surface area as a function of
distance (kilometers) from the mouth of the Pearl River. Data from US ACE
(1970).
z
o
o
LU
cc
100	150
PRECIPITATION (cm)
200
Figure 3-5. The long-term (1931-1988) annual mean precipitation for the 10 climatic
regions in Mississippi.
precipitation, based on monthly summaries for 1931-1988, for the 10 climatic regions in
Mississippi. Note the general increase in precipitation from north to south (from region 1
to region 10).
70

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Monthly runoff data (Figure 3-6) reveal that the seasonal pattern is the same
throughout the basin. In contrast, monthly mean precipitation data for several stations in
the basin (Figure 3-7) have a bimodal distribution that peaks in March and August. The
discrepancy between these two sets of data is explained by the higher evapotranspiration
rate during the summer, which reduces runoff. Monthly means of discharge calculated
from daily values over the period of record are shown in Figure 3-8. The seasonal pattern
is quite similar at all stations; a peak occurs in the first part of the year (January through
May), and flows are low throughout the summer period. This distribution closely follows
the seasonal runoff pattern (Figure 3-6), indicating that the river is strongly controlled by
precipitation.
The lower Pearl (lower 70 km) is influenced by Gulf of Mexico tides through
Mississippi Sound and Lake Borgne. This tidal influence leads to the development of a salt
wedge in the lower reaches of the East Pearl. Figure 3-9 shows the position of the salt
wedge as a function of river stage. The wedge extends northward from the mouth to a
maximum distance of about 25 km.
MONTH
Figure 3-6. Seasonal distribution of runoff for selected stations in the Pearl River basin
(see Figure 3-1) showing mean monthly runoff. Data from USACE (1970).
71

-------
LU
o
16 -
W 14 .
cr ~
LU
lH 12
5
EDINBURG
JACKSON
BOGALUSA
t—'—i—'—i—>—i—¦—i—'—i—"—i—>—i—<—i—"—i—<—r
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV
MONTH
Figure 3-7. Seasonal distribution of precipitation for selected stations in the Pearl River
basin (see Figure 3-1) showing mean monthly rainfall. Data from USACE
(1970).
600
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
MONTH
Figure 3-8. Seasonal distribution of discharge for selected stations in the Pearl River
basin (see Figure 3-1) showing mean monthly discharges.
72

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STAGE (cm)
Figure 3-9. Location of the salt wedge in the East Pearl River as a function of river stage.
"Distance" indicates the upper limit of the salt wedge from the mouth of the
river. Data from the USACE Vicksburg Office (copy of draft report).
The Offshore Area
The Pearl River plume also affects the adjacent coastal waters. The "zone of influence"
can be estimated using data in the literature. The tide within the Mississippi Sound area is
diurnal, with a mean diurnal range of about 0.34 m (Swenson and Chuang 1983) This
pattern was found to be consistent with water levels within Lake Pontchartrain, implying
that this range is typical for Lake Borgne. Using this tidal range estimate with an area of
Lake Borgne of 6.93 x 10^ m2 (Barrett 1971a) yields a tidal prism volume of about 2!36 x
10^ m3. The average flow for the Pearl River (at Bogalusa) is about 300 cms; flood flows
are about 550 cms, and low flows about 150 cms (see Figure 3-8). Calculating the
amount of fresh water discharged over a tidal cycle (25 hours) yields values of 2.7 x 10^,
4.95 x 10*7, and 1.35 x 10^ m^ for mean, flood, and low flow conditions respectively.
Thus, the freshwater flow from the Pearl River is about 11% of the total tidal prism, under
mean conditions, and can be as high as 21% during flood conditions. Using Barrett's
(1971a) estimate for the volume of Lake Borgne (1.17 x 10^ m^) along with the river flow
estimates, we arrive at replacement times (for all of Lake Borgne) of 45, 25, and 90 days
for mean, flood, and low flow conditions. Thus, it is not suprising that Barrett (1971b), in
his Louisiana estuarine inventory, noted that salinities within the Lake Borgne area are
inversely correlated with Pearl River discharge. He also noted that both turbidity and
73

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nitrates within the Lake E ~ rgne area appear to fluctuate with Pearl River discharge,
although he did not do a ;atistical analysis.
Sikora and Kjerfve (1985) studied factors influencing salinity at six stations within
Lake Pontchartrain (Figure 3-10). They concluded that the Pearl River discharge is a better
predictor of the salinities in the eastern part of the Lake (Little Woods) than are the rivers
entering directly into Lake Pontchartrain. Their analysis indicated that the Pearl River
explains about 40% of the variation in salinity within the east portion of Lake
Pontchartrain. Thus we can define a zone of influence of the Pearl River on the adjacent
coastal waters that includes Lake Borgne, the eastern section of Lake Pontchartrain, and
extends an unknown distance into Mississippi Sound (see Figure 3-10). Schroeder et. al
(1985) documented the existence of a recurrent pattern of westward flow that occurs under
the influence of northerly winds immediately south of the Mississippi-Alabama barrier
islands. This flow appears to enter the Chandeleur-Breton sound at the northern end. If it
extends towards Lake Borgne, this westward flow could serve to contain the Pearl River
waters to Lake Borgne and Lake Pontchartrain. Further data collection and analysis are
needed to refine assessments of the offshore influences of the Pearl River.
Figure 3-10. Map of the Lower Pearl River area and the adjacent coastal waters.
74

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Historical Changes
During the past 100 years, changes have been made within the Pearl River basin
that could affect the hydrologic regime of the river. In the late 1800s and early 1900s these
changes consisted primarily of the removal of obstructions and log jams within the river by
the USACE. These changes are summarized in Figure 3-11 (from J. R. Sedell, USDA,
Forest Sciences Laboratory). In general, a great deal of activity took place around the turn
of the century, and most of the obstructions were removed by 1900.
YEAR
Figure 3-11. Number of obstructions removed from the Pearl River basin from 1880
through 1920. Data from J. R. Sedell, USDA Forest Service Laboratory,
Corvallis, Oregon (unpublished).
According to the USACE records (USACE, 1970), a channel from Jackson to
Carthage, navigable at a 1.5-m stage of water, was authorized under the River and Harbor
Act of 1879, then modified to a 1.5-m-deep channel at low water by the River and Harbor
Act of 1880. Subsequently it was modified by the River and Harbor Act of 1886 to be a
0.61-m-deep channel of navigable width. A second project to create a high-water channel
from Carthage to Edinburg was combined with this project by the River and Harbor Act of
1902. To date, no work has been done on this project. Several other projects in the upper
basin were authorized, but not built. There are several USACE navigation projects in the
lower part of the basin. The first of these is a 2.74-m-deep, 91.46-m-wide channel from
the mouth of the East Pearl to Mississippi Sound. This channel was completed in 1900,
then restored to a depth of 2.74 m and width of 60.97 m in 1911. A navigation channel
with locks was completed on the West Pearl in 1953. It consists of a 30.48-m-wide
channel in the lower 52.8 km of the West Pearl; a 24.39-m-wide, 37.6-km-long lateral
75

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canal (with three locks) parallel to the natural channel; and a 30.48-m-wide, 17.0-km-long
channel from the lateral canal to Bogalusa. In addition to these projects, the Ross Barnett
dam and a 1-hectare reservoir, a local government project, were completed in 1964.
The Ross Barnett Dam was constructed on the Pearl River about 6 miles northeast
of Jackson in 1964 by the Pearl River Valley Water Supply District, an agency of the State
of Mississippi. The 30,000-acre lake formed by this dam, with a total storage volume of
about 310,000 acre-feet, provides recreation and an assured source of water supply for the
Jackson area in the amount of 150 million gallons per day.
The only other federal agency that has made modifications within the basin is the
Soil Conservation Service (SCS). Its work consisted of small projects to retard erosion
and to prevent localized flooding due to rainfall. The benefits listed for these projects
include reduction of damage to fences, roads, and bridges, and protection of local lands
from the three-year flood. The SCS has seven projects within the Pearl River basin (Figure
3-12). The strategies used include both structural (drainage ditches, dams) and land
treatment (farm ponds, planting, and land management) projects. The work completed to
date, most of which was completed in the early 1970s, on all of the projects is listed in
Table 3-1. In general, the area affected by these projects is fairly small. The SCS states in
the project reports that these projects are not expected to influence the main stem of the
Pearl River.
In summary, there have been relatively few changes to the Pearl River basin in
recent times (since 1900). The most extensive modifications have been in the Lower Pearl
and consist mainly of navigation channels. The Ross Barnett Reservoir is quite shallow
and therefore expected to have little effect on the flows of the Pearl River (USACE 1970).
The most significant changes probably occurred during the late 1800s, when major
obstructions to flow were removed.
STAGE AND DISCHARGE ANALYSIS
The Data Base
Daily records of stage and discharge were obtained for a number of stations within
the basin. The station locations are indicated in Figure 3-13; Table 3-2 lists the dates of
record for each of the stations. Precipitation data were obtained through the Louisiana
Office of the State Climatologist. These data were in the form of monthly total precipitation
for the 10 climatic regions of Mississippi (Figure 3-1) from 1931 through 1988.
Inspection of the stage data revealed that most of the records were of short duration, which
precluded analysis'of changes to the rating curve with time. Therefore, we also obtained
measured stages and discharges from the U.S. Geological Survey (USGS) in Jackson for
76

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Edinburg, Ofahoma, Jackson, and Monticello. The data were transcribed from the original
files, using decade intervals from 1900 through 1987. For each decade, enough years
were used (usually one or two) to define the rating curve for that decade interval.
rtm.


i >
4
) r


J
CkKtl*
Lsuifitna
MIES
Figure 3-12. Map of the Pearl River basin showing the locations of the seven
Soil Conservation Service projects within the basin.
77

-------
Table 3-1. Summary of Soil Conservation Service projects within the Pearl River basin for both land treatment and structural
measures.
I. Land Treatmenta
critical area	pasture and hayland	conservation
farm ponds planting	management planting	cropping tree planting other
Project Name (number) (ha)	(ha) (ha)	(ha) (ha)	(ha)
vj
CO
Bahala Creek
Copiah
Holliday Creek
Richland Creek
Standing Pine
Tallahaga Creek
Whitesand-Greens
Total
n. Structural Measures
42
294
1,368
0
386
38
5,176
890
246
0
7,595
3,069
1,653
2,748
719
701
9,002
11,082
4,659
2,426
0
443
98
0
4,418
0
1,855
3,140
203
536
0
3,744
2,974
284
1,963
615
689
0
5,059
1,497
1,214
0
947
233
9,740
5,094
7,790
1,094
0
3,859
2,806
20,110
36,992
20,375
8,564
13,027
Project Name
drainage ditches3
diversion ditchesa
area controlled by structures
channels
(km)
(km)
(ha)
(km)
Bahala
0
0
nd
nd
Copiah
9.45
0
l,157a>b
9.36a'b
Holliday Creek
4.91
8.67
2,705a'c
0s
Richland Creek
5.26
0
2,926a>d
26.14a'd
Standing Pine
24.68
0
4,519a»e
38.91a'e
Tallahaga
0
0
9,206a>f
20.38a»e
Whitesand-Greens
0.70
4.91
542a'8
03
Total
45.00
13.58
21,055
94.79

-------
Table 3-1. Continued
a Data from Watershed Progress Report for Mississippi.. Soil Conservation Service, Jackson, Mississippi. The "other"
category includes land described as "adequately treated."
b Data from Project Map for Copiah Creek Watershed. U.S. Dept. of Agriculture, Soil Conservation Service, January 1987,
Jackson, Mississippi. Map No. 4-R-36718. February 1981.
c Data from Supplemental Watershed Work Plan and Work Agreement No. 1. Holliday Creek Watershed, Jefferson Davis and
Marion Counties Mississippi. U.S. Dept. of Agriculture, Soil Conservation Service. March 1979.
d Data from Project Map for Richland Creek Watershed. U.S. Dept. of Agriculture, Soil Conservation Service, Jackson,
Mississippi. Map No. 4-R-36666. February 1981.
e Data from Watershed Work Plan, Standing Pine Watershed Leake and Neshoba County, Mississippi. Standing Pine Drainage
District, Leake and Neshoba County Soil Conservation Districts. November 1964.
f Data from Tallahaga Creek Watershed, Winston, Choctaw and Neshoba Counties, Mississippi, Supplemental Watershed Plan
No. 1 and Supplemental Watershed Agreement No. 2. U.S. Dept. of Agriculture, Soil Conservation Service, Jackson,
Mississippi. July 1985.
8 Data from Whitesand-Greens Creeks Wartershed, Jefferson Davis and dawrence Counties, Mississippi, Supplemental
Watershed Plan No. 1 and Supplemental Watershed Agreement No. 1. U.S. Dept. of Agriculture, Soil Conservation Service,
Jackson, Mississippi. August 1985.

-------
YockuookiAy
Bmr
02482550
Bess Bmttt
Rtstnrvir
02414 50 D.
02414(30
024*2000
024 83001
sTwe*Uft«U
Cmk
02486 j)00(
02585700'
r 024 88 oo r
024>85001
' 8tre&? Rivtr
. Vliti Bui Cn«k
02418 70 0
TfMl
tf MISS.

i *

A
«
) *


J
024800001
Boffut Chitto
Rivtr
-Purl Rivtr
MISSISSIPPI
024805001
<
02480105
02402000'
>024805001
'Bogihui
LOmSUWA
V«t
Purl
Likt PoMebrtni*
Mif risslj)! Soul
N
0
k.
20
MILES
Figure 3-13. Map of the Pearl River basin showing the locations of the USGS
daily stage and discharge records analyzed for this study.
80

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Table 3-2. Summary of United States Geological Survey (USGS) daily discharge and stage
records from the Pearl River basin. Data sets are those that are presently available in
computer-compatible format
Station
Location
Start Date
End date
N3
Elevation^
(ft)
Daily Discharge Data
02481880	Pearl River @ Bumside, Ml
02482000	Pearl River @ Edinburg, MI
02482550	Pearl River @ Carthage, MI
02483000	Tuscolameta Creek @ Walnut Grove, MI
02484500	Yockanookany River @ Ofahoma, MI
02484630	Pearl River @ Ratcliff, MI
02585700	Hanging Moss Creek @ Jackson. MI
02486000	Pearl River @ Jackson, MI
02488000	Pearl RiveT @ Rockport, MI
02488500	Pearl River @ Monticello, MI
02488700	White Sand Creek @ Oak Vale, MI
02489000	Pearl River @ Columbia, MI
02489500	Pearl River @ Bogalusa, LA
02490105	Bogue Lusa Creek @ Highway 439, LA
02490500	Bogue Chitto River @ Tylertown, MI
02492000	Bogue Chitio River @ Bush, LA
Daily Stage Data
02481880	Pearl River @ Bumside, MI
02482000	Pearl River @ Edinburg, MI
02482550	Pearl River @ Carthage, MI
02483000	Tuscolameta Creek @ Walnut Grove, MI
02484500	Yockanookany River @ Ofahoma, MI
02484630	Pearl River @ Ratcliff, MI
02585700	Hanging Moss Creek @ Jackson, MI
02486000	Pearl River @ Jackson, MI
02488000	Pearl River @ Rockport, MI
02488500	Pearl River @ Monticello, MI
02488700	White Sand Creek @ Oak Vale, MI
02489000	Pearl River @ Columbia, MI
02489500	Pearl River @ Bogalusa, LA
02490105	Bogue Lusa Creek @ Highway 439, LA
02490500	Bogue Chitto River @ Tylertown, MI
02492000	Bogue Chitto RiveT @ Bush, LA
December 1980
October 1928
October 1962
October 1939
October 1943
January 1981
October 1980
October 1901
October 1938
October 1938
October 1965
October 1928
October 1938
October 1963
October 1944
October 1937
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1987
September 1980
September 1984
October 1984
September 1987
October 1984
2,466
21,549
9,131
17,532
16,071
2,495
2.556
25,564
5,843
17,897
8,035
9,862
17,167
7,675
15,705
17,171
December 1980
September
1987
2,495
October 1971
September
1987
5.509
October 1971
September
1987
5,844
October 1971
September
1987
5,753
October 1971
September
1987
5,844
no stage data



October 1980
September
1987
2,556
October 1960
September
1987
7,883
October 1984
September
1987
1,095
January, 1972
September
1987
5,387
October 1972
September
1987
5,235
no stage data



no stage data



no stage data



October 1972
September
1987
5,447
no stage data



376.30
341.67
315.24
322.70c
374.34
290.00
260.00d
233.70e
180.90
158.66
182.20f
115.818
55.00
227.40
aN = The number of data points in each record.
^Elevation = The gage elevation relative to the 1929 National Geodetic Vertical Datum (NGVD).
cPrior to 1 October 1971, the datum was 10.00 ft higher.
dprior to 11 July 1971, the datum was 1.33 ft higher.
ePrior to 1 October 1975, the datum was 1.20 ft higher.
^Mississippi state highway datum.
SFrom August 1928 through May 1934 the datum was 0.37 ft higher.
81

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Figures 3-14 through 3-18 present annual mean discharge and annual mean stage
for various stations within the Pearl River basin. These five stations are typical of all of the
data records. The annual total rainfall for central Mississippi (region 5) and south central
Mississippi (region 8) are presented in Figure 3-19.
Analysis Procedures
The analytical procedures used for this analysis were similar to those used by
Wiseman and Swenson (1988) to analyze long-term salinity data from the Louisiana coastal
zone. The following general questions were addressed:
1.	Has there been a statistically significant change in the mean discharge or
stage in the Pearl River basin?
2.	Has there been a statistically significant change in the variance about the
mean discharge or stage in the Pearl River basin?
3.	Has there been a statistically significant change in the maximum discharge
or stage in the Pearl River basin?
4.	Has there been a statistically significant change in the minimum discharge
or stage in the Pearl River basin?
5.	Has there been a change in the rating curves (discharge as a function of
stage) in the Pearl River basin?
If the answer to any of these was yes, then two more questions were asked:
1.	What is the magnitude of the change?
2.	Can the changes be explained as natural variability?
The investigation into the secular trends was begun by fitting a linear model to the
data sets using time with annual harmonic (sine and cosine) terms to remove the seasonal
correlation effects as independent variables.. The slope parameter of the model was then
tested for statistical significance (Neter and Wasserman 1974). In all tests a significance
level of 95% was used. The procedures used in the analysis were the GLM (general linear
models) procedures supported on the LSU Mainframe computer by Statistical Analysis
System ( SAS, 1985a, b). The analyses were run on both the stage and the discharge for
the monthly means, variance about the mean, minima, and maxima. The annual means
were then calculated for each of the stations, and a linear model was fit using time as the
independent variable. The annual means were used as another method of averaging out the
strong seasonal signal in the data.
°2

-------
Visual inspection of the annual data (Figures 3-14 through 3-19) revealed that the
data series has two distinct parts: the period before 1971 and the period from 1971 through
1988, during which three very large flood events occurred. These three floods may have
strongly influenced the analysis results. To investigate this, we divided the data into two
series: (1) a pre-1971 series and (2) a 1971-1988 series. Each of these series was then
YEAR
1920 1930 1940
1950 1960 1970 1980 1990
YEAR
Figure 3-14. Yearly mean discharge, in cubic meters per second (top) and yearly mean
stage in meters (bottom) for the Pearl River at Edinburg, Mississippi.
T3

-------
cr>
5
o
1920 1930
1940 1950 1960
YEAR
1970 1980
1990
U)
cc
LU
UJ
5
1920
1930 1940
1950 1960
YEAR
1970 1980 1990
Figure 3-15. Yearly mean discharge, in cubic meters per second (top) and yearly mean
stage in meters (bottom) for the Yockanookany River at Ofahoma,
Mississippi.

-------
to
2
o
400
300 -
200 "
100 -
2000
t	1	r
1920 1930 1940
t	'	r
1950 1960
YEAR
1970 1980 1990
Figure 3-16. Yearly mean discharge in cubic meters per second (top) and yearly mean
stage in meters (bottom) for the Pearl River at Jackson, Mississippi.
85

-------
500
w
5
o
400 "
300 -
200 "
100 -
	'	1	r	1	
1920 1930 1940
—I	'
1950
YEAR
1960
1970 1980 1990
-»	r
1920 1930 1940
i ¦r
1950 1960
YEAR
1970 1980
1990
Figure 3-17. Yearly mean discharge in cubic meters per second (top) and yearly mean
stage in meters (bottom) for the Pearl River at Monticello, Mississippi.
86

-------
1000
1920 1930 1940
1950 1960
YEAR
1970 1980 1990
-i			1	>	1			r
1920 1930 1940 1950 1960 1970 1980 1990
Figure 3-18. Yearly mean discharge, in cubic meters per second (top) and yearly mean
stage in meters (bottom) for the Pearl River at Bogalusa, Mississippi.
87

-------
w
cc
UJ
h-
UJ
z
UJ
o
250
200 "
150 -
100
1920 1930
1940 1950 1960
YEAR
1970 1980
1990
CO
cc
UJ
h—
UJ
2
UJ
O
250
200
-i	1	1	1	1	1	1-
1920 1930 1940 1950 1960 1970 1980 1990
YEAR
Figure 3-19. Total yearly precipitation for region 5 (central Mississippi) and region 8
(south central Mississippi).
88

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analyzed using the above procedures. In addition, a fourth series (the "edited" series) was
created in which only the large peaks (1974,1979, and 1983) were removal It is also
evident from these plots that rainfall, stage, and discharge are strongly related.
A nonparametric test for the presence of a trend, the seasonal Kendall-Tau (Hirsch
et al. 1982), was also used on the monthly data. This procedure tests for the presence of a
statistically significant, monotonic trend in the data. It is important to note that the trend
need not be linear. This test was originally designed for data that are extremely "spikey" in
nature. The test does not determine the slope of the trend, only whether a trend exists and
its sign.
The stage-discharge relationship was investigated by plotting a rating curve for each
of the stations for each decade. The curves were then examined to detect any evidence of a
consistent change over time. Of particular interest was whether the discharge for a given
stage had increased, decreased, or remained the same over the last 40-50 years.
RESULTS AND DISCUSSION
When the linear trend plus the seasonal cycle were fit to the monthly mean and to
the variance about the monthly mean data, the trend appeared to be significant in several
cases for both discharge and stage, if the whole data base was used. A correlation analysis
between annual rainfall and river discharge and stage (Table 3-3) indicates that the rainfall
in central Mississippi explains approximately 80% of the variance in the Pearl River
discharge and stage data. Thus, the data were edited (as explained above) to account for
the rainfall effect. If the large rainfall events of 1974,1989, and 1983 are removed, mean
discharge has a significant slope through time at only only three stations (White Sand Creek
at Oakvale, Pearl River at Columbia, and Bogue Chitto at Highway 439; Table 3-4). All of
these stations are in the lower portion of the basin, and the results are not consistent (two
are positive, one is negative). The river stage decreased at stations in the northern part of
the basin (Edinburg, Carthage, the Yockanookany at Ofahoma), and did not change at
main-stem stations in the rest of the basin. The Bogue Chitto at Tylertown also showed a
decrease. Similar results were obtained for the variances about the monthly mean (Table 3-
4 ) as well as the minima and maxima (Table 3-5); only a few stations remained significant
if the large rainfall events were removed.
The above procedure was also used to analyze the annual means, variances about
the annual means, annual minima, and annual maxima for both stage and discharge. The
results are presented in Tables 3-6 and 3-7 Again, once the rainfall effect is accounted for,
no trends in the annual discharge are statistically significant except for that for White Sand
89

-------
Creek at Oa'cvale. The results for annual stage are similar; only the Yockanookany at
Ofahoma, the Bogalusa at Tylertown, and the Pearl at Carthage have statistically significant
trends (all negative). Results for the variance about the annual mean (Table 3-6) indicate no
statistically significant trends for discharge and only two stations (Pearl at Walnut Grove
and Pearl at Oakvale)with significant trends in stage (both negative). Annual minima and
maxima (Table 3-7) were also similar with no statistically significant trends in discharge
and only one station with a significant positive trend in stage (Jackson). Appendix A
presents detailed statistical results for all of the analyses.
Stage discharge curves for the gaged stations are shown in Figures 3-20 through 3-
23. It is evident from these figures that the stage-discharge relationship within the Pearl
River has not changed over the last 40-50 years.
Table 3-3. Correlation between mean yearly total precipitation for central Mississippi
(Region 5) and yearly mean discharge and stage for the Pearl River at several
locations. Correlations are significant at the 95% level unless indicated
otherwise.
Station	Pearson Correlation Probability Number of Years
Discharge
Burnside
Edinburg
Carthage
Yockanookany
Ratliff
Jackson
Rockport
Monticello
Columbia
Bogalusa
Stage
Bum side
Edinburg
Carthage
Yockanookany
Ratliff
Jackson
Rockport
Monticello
Columbia
Bogalusa
0.7107
0.8764
0.9067
0.9269
0.8644
0.8886
0.7559
0.8805
0.1352*
0.8556
0.6678*
0.7977
0.8878
0.8763
0.7908
0.7544*
0.8391
0.0482
0.0001
0.0001
0.0001
0.0121
0.0001
0.0003
0.0001
0.5103
0.0001
0.0703
0.0001
0.0001
0.0001
no data
0.0001
0.2456
0.0001
no data
no data
8
57
26
45
7
57
18
50
26
58
8
17
17
17
26
4
16
Not significant.
90

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Table 3-4. Summary statistics from analysis of monthly mean and variance about the monthly
mean discharge and stage as a function of time for USGS stations in the Pearl River
basin using a seasonally adjusted ANOVA model. Listed are the results of analysis
using the entire data set, using only data before 1971, using only data for 1971-1988,
and using the edited data set (1974,1979, and 1983 deleted).
	Mean	 	Variance about the mean
Station	all data <1971 71-88 edited all data <1971 71-88 edited
(cms/mo) (cms/mo) (cms/mo) (cms/mo) (cms2/mo) (cms2/mo) (cms2/mo) (cms2/mo)
Discharge data (cubic meters/second)





Bumside
NSa
NDb
NS
NS
NS
ND
NS
NS
Edinburg
0.019
NS
NS
NS
5.26
NS
NS
NS
Carthage
0.105
0.229
NS
NS
NS
NS
NS
NS
Walnut Grove
0.014
NS
NS
NS
1.959
NS
NS
NS
Ofahoma
NS
NS
NS
NS
NS
NS
NS
NS
Rati iff
ND
NS
NS
NS
ND
NS
NS
NS
Hanging Moss
ND
NS
NS
NS
ND
NS
NS
NS
Jackson
0.039
NS
NS
NS
15.172
NS
NS
NS
Rockport
NS
0.757
NS
NS
NS
125.780
NS
NS
Monticello
0.121
NS
NS
NS
44.077
NS
NS
22.917
Oak Vale
0.009
NS
NS
0.007
NS
NS
NS
NS
Columbia
-0.177
NS
NS
-0.161
NS
NS
NS
NS
Bogalusa
0.228
NS
NS
NS
70.684
NS
NS
38.431
Highway 439
0.007
NS
NS
0.006
NS
NS
NS
NS
Tylertown
NS
-0.032
NS
NS
NS
NS
NS
NS
Bush
NS
-0.031
NS
NS
NS
NS
NS
NS
Stage data (meters)







Bumside
NS
ND
NS
NS
NS
ND
NS
NS
Edinburg
NS
ND
NS
-0.004
NS
ND
NS
NS
Carthage
-0.004
ND
-0.004
-0.005
NS
ND
NS
NS
Walnut Grove
NS
ND
NS
NS
NS
ND
NS
-0.002
Ofahoma
-0.004
ND
-0.004
-0.005
NS
ND
NS
-0.002
Ratliff
ND
ND
ND
ND
ND
ND
ND
ND
Hanging Moss
ND
ND
NS
NS
ND
ND
NS
NS
Jackson
NS
NS
-0.004
NS
NS
NS
NS
NS
Rockport
NS
ND
NS
NS
NS
ND
NS
NS
Monticello
NS
ND
NS
NS
NS
ND
NS
NS
Oak Vale
NS
ND
NS
NS
NS
ND
NS
NS
Columbia
ND
ND
ND
ND
ND
ND
ND
ND
Bogalusa
ND
ND
ND
ND
ND
ND
ND
ND
Highway 439
ND
ND
ND
ND
ND
ND
ND
ND
Tylertown
-0.002
ND
-0.002
-0.002
ND
ND
NS
NS
Bush
ND
ND
ND
ND
ND
ND
ND
ND
aNS = Not significant at the 95% level.
&ND = No data.
91

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Table 3-5. Summary statistics from analysis of monthly minimum and monthly maximum
discharge and stage as a function of time for USGS stations in the Pearl River basin
using a seasonally adjusted ANOVA model. Listed are the results of analysis using
the entire data set, using only data before 1971, using only data for 1971-1988, and
using the edited data set (1974,1979, and 1983 deleted).
—		Minimum			Maximum	
Station	alldaia <1971 71-88 edited	all data <1971 71-88 edited
(cms/mo) (cms/mo) (cms/mo) (cms/mo) (cms2/mo) (cms2/mo) (cms2/mo) (cms2/mo)
Discharge data (cubic meters/second)





Bumside
NSa
NDb
NS
NS
NS
ND
NS
NS
Edinburg
0.004
NS
NS
NS
0.089
NS
NS
NS
Carthage
0.030
0.089
NS
0.019
0.369
NS
NS
NS
Walnut Grove
0.001
NS
NS
NS
0.077
NS
NS
NS
Ofahoma
NS
NS
NS
NS
NS
NS
NS
NS
Rati iff
ND
NS
NS
NS
ND
NS
NS
NS
Hanging Moss
ND
NS
NS
NS
ND
NS
NS
NS
Jackson
NS
NS
NS
NS
0.127
NS
NS
NS
Rockport
NS
NS
NS
NS
NS
1.559
NS
NS
Monticello
NS
NS
NS
NS
0.299
NS
NS
NS
Oak Vale
0.004
NS
0.001
0.004
NS
NS
NS
NS
Columbia
-0.082
NS
NS
NS
-0.316
NS
-0.028
-0.028
Bogalusa
0.071
NS
NS
NS
0.438
NS
NS
NS
Highway 439
0.002
NS
0.002
0.002
0.039
NS
NS
NS
Tylertown
-0.001
-0.014
NS
-0.002
NS
NS
NS
NS
Bush
NS
-0.015
NS
NS
NS
NS
NS
NS
Stage data (meters)







Bumside
NS
ND
NS
NS
NS
ND
NS
NS
Edinburg
NS
ND
NS
NS
NS
ND
NS
NS
Carthage
-.002
ND
-.002
-.002
-0.005
ND
-.005
-.006
Walnut Grove
.001
ND
.001
.001
NS ¦
ND
NS
NS
Ofahoma
-.003
ND
.003
.003
-0.006
ND
-.006
-.007
Rati iff
ND
ND
ND
ND
ND
ND
ND
ND
Hanging Moss
.001
ND .
.001
.001
NS
ND
NS
NS
Jackson
NS
-.009
NS
NS
.004
NS
NS
NS
Rockport
NS
ND
NS
NS
NS
ND
NS
NS
Monticello
NS
ND
NS
NS
NS
ND
NS
NS
Oak Vale
.0002
ND
0.002
0.002
.002
ND
-.002
-.002
Columbia
ND
ND
ND
ND
ND
ND
ND
ND
Bogalusa
ND
ND
ND
ND
ND
ND
ND
ND
Highway 439
ND
ND
ND
0.002
ND
ND
ND
ND
Tylertown
-.001
ND
-.001
-.001
-.004
ND
-.004
-.005
Bush
ND
ND
NS
NS
ND
ND
ND
ND
aNS = Not significant at the 95% level.
bND = No data.
92

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Table 3-6. Summary statistics from analysis of annual mean and variance about the annual mean
discharge and stage as a function of time for USGS stations in the Pearl River basin
using a seasonally adjusted ANOVA model. Listed are the results of analysis using
the entire data set, using only data before 1971, using only data for 1971-1988, and
using the edited data set (1974, 1979, and 1983 deleted).
	Mean			Variance about the mean	
Station	all data <1971 71-88 edited	all data <1971 71-88 edited
(cms/yr) (cms/yr) (cms/yr) (cms/yr) (cms2/yr) (cms2/yr) (cms2/yr) (cms2/yr)
Discharge data (cubic meters/second)
Burnside
NSa
NDb
NS
NS
NS
ND
NS
NS
Edinburg
0.273
NS
NS
NS
82.574
NS
NS
NS
Carthage
NS
3.873
NS
NS
NS
NS
NS
NS
Walnut Grove
0.192
NS
NS
NS
31.287
NS
NS
NS
Ofahoma
NS
NS
NS
NS
NS
NS
NS
NS
Ratiiff
ND
NS
NS
NS
ND
NS
NS
NS
Hanging Moss
ND
NS
NS
NS
ND
NS
NS
NS
Jackson
0.534
NS
NS
NS
312.830
NS
NS
NS
Rockport
NS
12.001
NS
NS
NS
5200.900
NS
NS
Monticello
1.791
NS
NS
NS
1423.650
NS
NS
NS
Oak Vale
0.13
NS
NS
0.112
NS
NS
NS
NS
Columbia
-2.500
NS
NS
NS
NS
NS
NS
NS
Bogalusa
3.110
NS
NS
NS
2384.820
NS
NS
NS
Highway 439
0.103
NS
NS
NS
NS
NS
NS
NS
Tylertown
NS
NS
NS
NS
NS
NS
NS
NS
Bush
NS
NS
NS
NS
NS
NS
NS
NS
Stage data (meters)
Burnside
NS
ND
NS
NS
NS
ND
NS
NS
Edinburg
NS
ND
NS
NS
NS
ND
NS
NS
Carthage
NS
ND
NS
-0.050
NS
ND
NS
NS
Walnut Grove
NS
ND
NS
NS
NS
ND
NS
-0.05
Ofahoma
-0.044
ND
-0.049
-0.050
NS
ND
NS
NS
Ratiiff
ND
ND
ND
ND
ND
ND
ND
ND
Hanging Moss
ND
ND
NS
NS
ND
ND
NS
NS
Jackson
NS
NS
NS
NS
NS
ND
NS
NS
Rockport
NS
ND
NS
NS
NS
ND
NS
NS
Monticello
NS
ND
NS
NS
NS
ND
NS
NS
Oak Vale
NS
ND
NS
NS
-0.004
ND
-0.004
-0.004
Columbia
ND
ND
ND
ND
ND
ND
ND
ND
Bogalusa
ND
ND
ND
ND
ND
ND
ND
ND
Highway 439
ND
ND
ND
ND
ND
ND
ND
ND
Tylertown
-0.019
ND
-0.019
-0.020
NS
ND
NS
NS
Bush
ND
ND
ND
ND
ND
ND
ND
ND
aNS = Not significant at the 95% level.
t>ND = No data.
93

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Table 3-7. Summary statistics from analysis of annual minimum and annual maximum discharge
and stage as a function of time for USGS stations in the Pearl River basin using a
seasonally adjusted ANOVA model. Listed are the results of analysis using the entire
data set, using only data before 1971, using only data for 1971-1988, and using the
edited data set (1974,1979, and 1983 deleted).
Minimum			Maximum
Station
all data
<1971
71-88
edited
all data
<1971
71-88
edited

(cms/yr)
(cms/yr)
(cms/yr)
(cms/yr) (cms2/yr)
(cms2/yr)
(cms2/yr)
(cms2/yr)
Discharge data
(cubic m
eters/second)





Bumside
NSa
NDb
NS
NS
NS
ND
NS
NS
Edinburg
NS
NS
NS
NS
NS
NS
NS
NS
Carthage
NS
NS ¦
NS
NS
NS
39.810
NS
NS
Walnut Grove
NS
NS
NS
NS
NS
NS
NS
NS
Ofahoma
.007
0.01
NS
.006
NS
NS
NS
NS
Ratliff
ND
NS
NS
NS
ND
NS
NS
NS
Hanging Moss
ND
NS
NS
NS
ND
NS
NS
NS
Jackson
NS
NS
NS
NS
NS
NS
NS
NS
Rockport
NS
NS
NS
NS
NS
69.900
NS
NS
Monticello
.095
NS
NS
NS
12.725
NS
NS
NS
Oak Vale
NS
NS
NS
.027
NS
NS
NS
NS
Columbia
-0.404
NS
NS
NS
NS
NS
NS
NS
Bogalusa
-0.295
NS
NS
NS
17.935
NS
NS
NS
Highway 439
NS
NS
NS
NS
NS
NS
NS
NS
Tylertown
NS
-0.094
NS
NS
NS
NS
NS
NS
Bush
NS
NS
NS
NS
NS
NS
NS
NS
Stage data (meters)







Bumside
NS
ND
NS
NS
NS
ND
NS
NS
Edinburg
NS
ND
NS
NS
NS
ND
NS
NS
Carthage
-0.027
ND
-0.027
-0.029
NS
ND
NS
NS
Walnut Grove
-0.069
ND
-0.069
-0.075
NS
ND
NS
NS
Ofahoma
-0.025
ND
-0.025
-0.025
NS
ND
NS
NS
Ratliff
ND
ND
ND
ND
ND
ND
ND
ND
Hanging Moss.
ND
ND
NS
NS
ND
ND
NS
NS
Jackson
NS
NS
NS
NS
0.156
NS
NS
0.136
Rockport
NS
ND
NS
NS
NS
ND
NS
NS
Monticello
NS
ND
NS
NS
NS
ND
NS
NS
Oak Vale
NS
ND
NS
NS
NS-
ND
NS
NS
Columbia
ND
ND
ND
ND
ND
ND
ND
ND
Bogalusa
ND
ND
ND
ND
ND
ND
ND
ND
Highway 439
ND
ND
ND
ND
ND
ND
ND
ND
Tylertown
-0.011
ND
-0.011
-0.01
NS
ND
NS
NS
Bush
ND
ND
ND
ND
ND
ND
ND
ND
aNS = Not significant at the 95% level.
bND = No data.
94

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500
400
300 -
200 -
100 -
~
A
1900-1929 Q CMS
1930-1931 Q CMS
1940 Q CMS
1950-1951 Q CMS
1960 Q CMS
1970-1971 Q CMS
1979-1980 Q CMS
•I*
I I | I
STAGE (m)
-|—¦—"—j—
10
12
Figure 3-20. Rating curve for the Pearl River at Edinburg, Mississippi, showing the
discharge (cubic feet per second) as a function of river stage (feet). Data
from the files of the USGS office in Jackson, Mississippi
500
400 H
300
200
100-j
G	1900-1929 Q CMS
•	1930-1931 Q CMS
D	1940 Q CMS
•	1950-1951 Q CMS
¦	1960 Q CMS
~	1970-1971 Q CMS
.4

¦
T
8
STAGE (m)
—r~
10
12
Figure 3-21. Rating curve for the Yockanookany River at Ofahoma, Mississippi,
showing the discharge (cubic feet per second) as a function of river stage
(feet). Data from the files of the USGS office in Jackson, Mississippi
95

-------
2500-
2000 ¦
1500 ¦
1000'
500
0
B
*
~
A
A
1900-1929 Q CMS
1930-1931 Q CMS
1940 Q CMS
1950-1951 Q CMS
1960 Q CMS
1970-1971 Q CMS
1979-1980 Q CMS
1968-1987 Q CMS





4	6
STAGE (m)
| I I I | I I I
8	10	12
Figure 3-22. Rating curve for the Pearl River at Jackson, Mississippi, showing the
discharge (cubic feet per second) as a function of river stage (feet). Data
from the files of the USGS office in Jackson, Mississippi.
2500
2000
1500 -
1000 ¦;
500 -
D
~
1900-1929 Q CMS
1930-1931 Q CMS
1940 Q CMS
1950-1951 Q CMS
1960 Q CMS
1970-1971 Q CMS
~ •
jflP*
JhJ**

i ¦
6
STAGE (m)
¦ >
10
12
Figure 3-23. Rating curve for the Pearl River at Monticello, Mississippi, showing the
discharge (cubic feet per second) as a function of river stage (feet). Data
from the files of the USGS office in Jackson, Mississippi.
96

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CONCLUSIONS
The analysis of the discharge and stage records from the Pearl River show the
following:
1.	The stages and discharges within the basin are controlled largely by
precipitation.
2.	Statistically significant trends do exist in the mean, variance about
the mean, the minima, and the maxima.
3.	Most of the trends have no consistent pattern except for the mean
stage, which appears to have decreased in the upper part of the
basin.
4.	The magnitudes of the trends are, in all cases, very small.
5.	The natural variability of the system is quite high and may hide weak
trends.
6.	No evidence exists that the stage-discharge relationship has changed
over the last 40-50 years.
In general, the river is "well-behaved" and most, if not all, of the fluctuations seen
in both the stage and the discharge records can be explained by natural climatic variability.
97

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REFERENCES
Barrett, B. B. 1971a. Cooperative Gulf of Mexico estuarine inventory and study,
Louisiana. Phase I, area description, and Phase n, biology. Louisiana Wildlife
and Fisheries Commission, New Orleans. 175 pp.
Barrett, B. B. 1971b. Cooperative Gulf of Mexico estuarine inventory and study,
Louisiana. Phase II, hydrology, and Phase III, sedimontology. Louisiana
Wildlife and Fisheries Commission, New Orleans. 191 pp.
Hirsch, R. M., J. R. Slack, and R. A. Smith. 1982. Techniques of trend analysis for
monthly water quality data. Water Resources Research 18(1):107-121.
Neter, J., and Wasserman. 1974. Applied linear statistical models, regression, analysis of
variance, and experimental designs. Richard D. Irwin, Homewood, 111. 842 pp.
SAS Institute, Inc. 1985a. SAS user's guide: basics, version 5 edition. SAS Institute,
Inc., Carry, N.C. 1290 pp.
SAS Institute, Inc. 1985b. SAS user's guide: statistics, version 5 edition. SAS Institute,
Inc., Carry, N.C. 956 pp.
Schroeder, W. W„ O. K. Huh, L. J. Rouse, Jr., and Wm. J. Wiseman, Jr. 1985.
Satellite observations of the circulation east of the Mississippi delta: cold-air
outbreak conditions. Remote Sensing of Environment 18:49-58.
Sikora, W. B., and B. J. Kjerfve. 1985. Factors influencing the salinity regime of Lake
Pontchartrain, Louisiana, a shallow coastal lagoon: analysis of a long-term data
set. Estuaries 8(2A): 170-180.
Swenson, E. M., and W. S. Chuang. 1983. Tidal and subtidal water volume exchange in
an estuarine system. Estuarine, Coastal and Shelf Science. 16:229-240.
U. S. Army. Corps of Engineers. 1970. Pearl River comprehensive basin study, volume
5: engineering studies. U.S. Army Corps of Engineers, Mobile District, Mobile,
Ala.
98

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Wiseman, W. J., and E. M. Swenson. 1988. Long-term salinity trends in Louisiana
estuaries. Chapter 6 in R. E. Turner and D. R. Cahoon, eds., Causes of wetland
loss in the coastal central Gulf of Mexico. Volume II, Technical naiTative. OCS
Study/MMS 87-0120. Final report submitted to Minerals Management Service,
New Orleans, La. 400 pp.
99

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CHAPTER 4: WATER QUALITY OF THE PEARL RIVER
BASIN, MISSISSIPPI AND LOUISIANA
101

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INTRODUCTION
Cumulative environmental impacts result from the total effect of many individual,
often small, development projects. While the impacts of individual projects may be
unmeasurable, collectively they can degrade the functional and structural integrity of
landscapes. Cumulative impacts in wetlands occur partly as a result of the traditional
procedure for dealing with site-specific permit applications. Permit evaluation focuses on
individual sites within the basin, thus seldom adequately reflecting the landscape context
(Gosselink and Lee 1989).
A large-scale landscape (e.g., watershed) approach is necessary to control
incremental losses. This type of focus allows site-specific permit requests to be considered
in the context of project impacts on the landscape as a whole. Focusing on the landscape as
a whole allows conservation of not only large-scale landscape structures and processes, but
also the structures and processes of smaller-scale subsystems.
The first step in developing a cumulative impact management plan is to assess the
status of the study area by analyzing historical data on various indices of landscape
structure and function. In the analysis one looks for trends through time as they relate to
alterations of the system. Alterations of drainage-basin water quality are usually reflected
in concentrations of suspended and dissolved stream constituents. Thus, water quality is a
functional indicator of the impact of various basin modifications. This chapter evaluates
historical water quality trends in streams within the Pearl River basin, with emphasis on
turbidity, total phosphorus (TP), and total Kjeldahl nitrogen (TKN).
Phosphorus
Phosphorus (P) is one of the major nun ients required for plant nutrition. As
phosphate, it is generally the nutrient that limits freshwater aquatic primary production
(U.S. Environmental Protection Agency 1976). Concern about the level of P in streams is
based primarily on its role in eutrophication. Stream P loading is increasing nationwide
because of increased use of P in industrial, agricultural, and domestic applications. This
widespread use makes it a good index of cultural disturbance (Childers and Gosselink
1990; Gosselink and Lee 1989).
Phosphorus readily adsorbs onto the surface of sediment particles. As a result, P
and suspended sediments are usually coupled. Furthermore, sediment runoff into streams
is positively related to precipitation, which causes erosion and runoff in disturbed
watersheds (Murphree et al. 1976; Ursic 1965). Accordingly, both P and suspended
sediments are often highly correlated with stream discharge.
103

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Nitrogen
Nitrogen (N), another essential plant nutrient, cycles rapidly between the
sedimentary, atmospheric, and aquatic environments. N and P are the two plant nutrients
most likely to limit plant growth. Because N exists in many forms, a single measure of
total N, presented as total Kjedahl nitrogen (TKN) was chosen for analysis in this report.
TKN includes NH4+, dissolved organic N, and particulate N. Nitrate and nitrite, both
biologically active, are not measured in TKN. However, data on these moieties were less
complete than data on TKN in the Pearl River basin. There are many biologically mediated
inputs to and losses of N from aquatic environments, for example, N fixation,
denitrification, atmospheric deposition, and anthropogenic inputs from agricultural,
muncipal, and industrial sources. Interconversions among these different forms of N occur
rapidly in nature, and for the Pearl River basin, TKN is the best available index of total
active N in the stream system.
MATERIALS AND METHODS
Site
The Pearl River basin is located in Mississippi and Louisiana (Figure 4-1, inset).
The Pearl River originates in central Mississippi and flows south along the Mississippi-
Louisiana border, eventually emptying into the Gulf of Mexico. The basin covers 2.25
million ha and includes all or portions of 27 parishes and counties in both states. It is
characterized by a variety of terrestrial and aquatic habitats, including upland, bottomland,
coniferous, and deciduous forests, and cypress swamps, as well as fresh and brackish
marshes. According to 1987 land use data, 52% of the basin is upland forest, 12% is
forested wetland, and < 1% is herbaceous marsh. Agricultural land makes up 31% of the
total area. Before settlement by Europeans, the basin was probably almost completely
forested.
Historical records of hydrology and water quality at five stations within the basin
were analyzed. These were the only Pearl River basin stations with at least 10 years of
continuous monthly water quality data. Water quality records were obtained from the
Louisiana Department of Environmental Quality, the U.S. Geological Survey's National
Stream Quality Accounting Network records (NASQAN), and the Mississippi State Board
of Health. Turbidity sampling typically began in the late 1950s, and collection of nutrient
data began in the late 1960s. (Table 4-1 summarizes the extent of the data sets.) The data
are monthly values, not monthly means.
104

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Richland
Sub-Basin
Bogue Chitto
Sub-Basin
Yockanooluny
Sub-Basin
Pelahatchie
Sub-Basin
Lower Peari
Sub-Basin
Upper Pearl
Sub-Basin
TEN*
MISS.





if M

Rivers
Sub unit boundaries
Kilometers
0	10 20 30 40
	1	1	I	I	I
Figure 4-1. Hydrologic subunits and water quality stations of the Pearl River basin.
105

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Table 4-1. Length of record, with number of ob servations given in parentheses, by site
for each water quality parameter of concern.
Station
Turbidity
TP
TKN
Ross Barnett North
1969-87 (215)
1969-87 (215)
DNAa
Ross Barnett South
1969-87 (217)
1969-87 (217)
DNA
Bogue Chitto at Bush
1974-87 (104)
1974-87 (86)
1974-87 (81)
Pearl River at Bogalusa
1958-88 (426)
1973-88 (204)
1973-88(192)
Bogue Lusa Creek at Bogalusa
1958-88 (238)
1978-88 (115)
78-88 (115)
aDNA = data not available.
106

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Water Quality Data Analyses
We analyzed TKN, TP, and turbidity records at two stations on the Pearl River in
the upper basin and three in the lower basin. Because many water quality parameters are
strongly influenced by stream discharge (Smith et al. 1982), we used methods described by
Hirsch et al. (1982) to remove the variability in the data due to discharge by adjusting
nutrient concentrations for flow. For this analysis we ran simple linear regressions of TP,
TKN, and turbidity on discharge. The residuals, which are the flow-adjusted data, were
subsequently subjected to linear regressions on time. In general, the flow-adjusted data
regressions contained nonhomogeneous variances. Consequently, for statistical purposes
the data were ranked and analyses were performed on the ranked data (Siegel and Castellan
1988). Rank correlation coefficients measure whether Y increases (or decreases) with X.
When data are ranked the units of the variables are lost, but the relative position of each
data point is maintained. All analyses were conducted using the General Linear Model
(GLM) procedure (SAS Institute 1985).
Nutrient Flux Measurements
Fluxes of nutrients and materials from the lower Pearl River basin (Louisiana and
Mississippi) were determined using data from the two southernmost water quality stations:
Bogue Chitto at Bush and Pearl River at Bogalusa. The Bogue Chitto River discharges
into the Pearl River less than 10 km downstream of the sampling site and drains the Bogue
Chitto sub-basin in the southwestern portion of the Pearl River basin. All areas east and
north of this sub-basin drain into the Pearl River, and the Bogalusa sampling station is
located approximately 20 km upstream of the confluence with the Bogue Chitto River. Just
south of this confluence, the Pearl River splits into east and west channels in the estuarine
portion of the basin.
To calculate fluxes of the nutrients (TKN, TP, and suspended sediments--e.g.,
turbidity), we used concentration data plus river discharge data from both stations. The
discharge data set at the Bogue Chitto site limited these calculations to an 11-year interval,
1974-1985. Data at both sites were available for varying intervals, from monthly to
quarterly. Daily fluxes of turbidity, TP, and TKN were computed as the product of
instantaneous discharge (in m^s"1) and concentration (in mg-1"1), and converted to
g-day_1 (or millions of NTU-day for turbidity) for both stations. Simple linear
interpolation was used to determine nutrient and sediment fluxes in the intervals between
sampling events. From these estimated annual flux patterns, total annual fluxes (in metric
tons NTU, P, and N-yr1) were computed for both sites individually using first-order
107

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Runga-Kutta integration techniques. Where an interval between samplings spanned two
years (e.g., 15 December 1975 through 30 January 1976), the area under the curve was
computed and proportionally split between the two years (in this example, 33.3% of the
total flux between 15 December 1975 and 30 January 1976 is assumed to have occurred in
1975 and 66.7% in 1976). The Microsoft Excel® spreadsheet software program was used
for all flux computations.
RESULTS
Water Quality Trends
Table 4-2 presents the slope direction (i.e., the regression coefficient), the
significance level (P <), and the coefficient of determination (R2) for all significant
regressions, both basinwide and for individual stations. The figures referenced in the
following discussion display real (i.e., unranked) data for easy comprehension, although
statistical evaluations of trends in these data were based on analyses of the ranked data.
Table 4-3 summarizes mean concentrations of turbidity, TP, and TKN at each of the
stations, and supplies data on land use in the sub-basin upstream.
Basinwide
Since the recognition and management of cumulative impacts is focused at the
landscape level, the trends in the data for the entire basin will be presented first
Turbidity. In undisturbed forested watersheds, sediment and nutrient loads are
often diluted by high stream flows because erosion increase is minimal (Smith et al. 1982).
Consequently, a regression of concentration on discharge has a negative slope. In
disturbed watersheds turbidity and nutrient concentrations generally increase during high
discharge (i.e., the regression slope is positive), presumably because of erosion from
disturbed soil surfaces.
Figure 4-2a shows the regression of turbidity on discharge for the Pearl River
basin. The trend in the raw data was not significant. However, the regression of rank
turbidity on rank flow basinwide had a highly significant (P < 0.01) positive slope; flow
accounted for 17% of the variability in turbidity (Table 4-2). The residual values from this
regression (the rank flow-adjusted values of turbidity) decreased significantly over time
(Figure 4-2b), though the data showed an increased spread beginning in the 1970s. The
reason for this anomaly is unknown, but may be related to an increase in the sensitivity of
the analytical technique for measuring turbidity. Mean discharge of the Pearl River
increased during the 1970s and early 1980s. Since turbidity is positively related to
108

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Table 4-2. Simple linear regressions of several water quality variables for the Pearl River basin as a whole, Ross Barnett north, Ross
Barnett South, Bogue Lusa Creek at Bogalusa, Pearl River at Bogalusa, and Bogue Chitto at Bush. Shown are the slope
direction ("+" = pos., = neg.), probability of obtaining a more significant relationship by change alone (P>), and the
coefficient of determination (R2).
North	South Bogue Lusa Crk Pearl River Bogue Chitto
Linear Regression	Basinwide Ross Barnett Ross Barnett at Bogalusa at Bogalusa	at Bush
Rank turbidity on
date
(-) .0001
.13
NS
	
NS
	
— .0001 .09
(-) .0001
.09
(-)
.0271
.05
Rank turbidity on
rank flow
(+) .0001
.17
NS
	
NS
—
NS 	
(+) .0001
.26
(+)
.0001
.62
Flow-adjusted rank
turbidity on date,
residuals
(-) .0001
.13
NS
	
NS

(-) .0001 .44
(-) .0001
.16
NS


Raw TP on date
(-) .0001
.02
(-)
.0001 .10
(-)
.0207 .02
NS 	
NS —
—
NS
—
—
Rank TP on date
NS —
—
(-)
.0002 .06
NS
— —
NS 	
NS —
—
(-)
.0018
.11
Rank TP on
rank flow
(+) .0001
.14
NS
—
NS
—
(+) .0149 .08
(+) .0041
.12
(+)
.0041
.12
Flow-adjusted rank
TP on date,
residuals
NS —
_
NS

NS

NS 	
NS —

NS


TKN mi date
(+) .0042
.02
DNA
	
DNA
— —
(+) .0026 .08
(+) .0001
.10
NS
—
—
TKN vs. TP
(+) .0001
.07
DNA
	
DNA
— —
(+) .0001 .12
NA —
—
NS
—
—
Flow on date
NS —
—
DNA
	
DNA
— —
(+) .0033 .03
(+) .0115
.02
NS
—
—
N:P
9:1

DNA
	
DNA
— —
17:1
9:1





-------
Table 4-3. Summary of water quality analyses for the five Pearl River basin sites.
TP
Station/Sub-basin Concentration
(mg"1)
TP TKN TKN
Trend3 Concentration Trend3
(mg"1)
TP Values
>0.1 mg"l
(%)
Turbidity
Flow
(P>)
on
R2
Turbidity
Trend3
N:P
ir
(molar)
Sub-basin
i Agriculture
(%)
Sub-basin
Forested
(%)
Tributary with
Forested Edge
(%)
Ross Barneft North/
Yockanookany
.09
(-)
DNAb
..
32
NS

—
DNA
27
70
97
Ross Barnett South/
Pelahatchie Creek
.08
(-)
DNA
"
29
NS
-
~
DNA
24
72
89
Bogue Lusa Creek
at Bogalusa/
Lower Pearl
.04
NS
.49
(+)
3
NS
NS
.
37.6
34
60
80
Pearl at Bogalusa/
Lower Pearl
.12
NS
.75
(+)
30
.0001
.26
(+)
19.9
34
60
80
Bogue Chitto at Bush
Bogue Chitto
.08
(-)
.62
(-)
26
.0001
.62
(+)
22.1
45
52
71
a Slope of regression of P vs. time,
b DNA = data not available.

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TURBIDITY
300
400
300
200
100
3000
300
200
D
S ioo
-loov
0BAPR57
140EC70	22AUGS4
DATS
O1MAY06
Figure 4-2. Turbidity data (Nephelometric turbidity units [NTU]) basinwide for the
Pearl River Watershed. Turbidity on flow (a) shows a significant
positive trend. Once turbidity was adjusted for flow (b), it decreased over
time.
Ill

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discharge, an increase in turbidity with time might be expected. The relationship was
negative, however, both for rank turbidity and for flow-adjusted rank turbidity.
Phosphorus. TP records date back to 1969 at two sites and to the 1970s at the
other three (Table 4-1). There was a significant (P < .05) positive relationship between
rank TP and rank flow in the basinwide data (Figure 4-3a). Once the TP values were
adjusted for flow, the residuals exhibited no significant temporal trends over the period of
record (Figure 4-3b), although the absolute concentrations decreased through time (Figure
4-3c).
The absolute concentration of TP is another measure of a watershed's health. The
EPA has suggested a standard for running streams, 0.1 mg-TP-H, above which
eutrophication usually occurs (U. S. Environmental Protection Agency 1976). Basinwide,
this level was exceeded 24% of the time.
Nitrogen. Considering data for all stations, TKN increased slowly through time
(Figure 4-4a). There was a highly significant increase in the annual mean N-to-P ratio
basinwide (Figure 4-4b), ranging (on a mass basis) from a mean of 7 in the 1970s to 10 in
the 1980s. The mean molar ratio increased from 15.5 to 22.1. The ratio of N to P
indicates which nutrient is limiting to aquatic primary production. Generally, when the
mean N-to-P ratio falls below 10 or 15, N becomes the limiting nutrient (Hecky and
Kilham 1988). The increase in the ratio of N to P was caused by both an increase in TKN
and a decrease in TP concentrations over the period of record
Site-Specific Results
For the basin as a whole, a multisource regression was performed on turbidity,
with discharge as the covariable and stations as the class variable. The highly significant
interaction effect between discharge and station indicated that the turbidity-discharge
relationships differed for the various stations. Therefore, separate analyses were
performed on each of the five water quality stations. The trends at the five stations were
variable; some sites exhibited characteristics of relatively healthy, intact landscapes, while
others displayed trends of more disturbed sites.
At the two most northern stations, Ross Barnett North and South (Figure 4-1),
neither rank turbidity nor rank TP was significantly related to flow. For Bogue Lusa
Creek, rank turbidity was unrelated to flow, but rank TP was positively related to flow.
Highly significant, positive slopes existed for both rank turbidity and rank TP versus flow
at both the Bogue Chitto and Pearl at Bogalusa stations, where flow explained 62% and
112

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06APR57
06APR57
1 4DEC70
22AUCB4
0 1MAY9B
SATE
14DEC70
22AUGB4
01MAY9B
un
Figure 4-3. TP (mgl*1) showed a significant, positive correlation with flow for the
basinwide data (a). Once the variation due to flow was removed there were
no trends over time (b). The absolute concentration of TP decreased over
time (c).
113

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N*MT • ©
nut
Figure 4-4. (a) Absolute concentrations of TKN (mg-1*1) increased over time, (b) N-to-
P ratios (mass basis) for the entire Pearl River basin had a highly significant
positive slope when regressed on time.
114

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26% of the variability in turbidity, respectively, and 12% of the variability in TP for both
sites (Table 4-2).
Bogue Lusa Creek had TP values that exceeded the EPA criterion of 0.1 mg-1'1
only 3% of the time, while Ross Bamett North and South exceeded it at 32% and 29% of
the data points, respectively. At these Ross Bamett sites, however, TP decreased with time
and most of the high values appear to have occurred in the early 1970s (Figure 4-5a-c).
For the Bogue Chitto and Pearl at Bogalusa sites, 26% and 30% of the values,
respectively, were above 0.1 mg TPl'l.
TKN concentrations increased over time in Bogue Lusa Creek and in the Pearl
River at Bogalusa, while Bogue Chitto remained constant (Figure 4-6). TKN data were
not collected at Ross Bamett North and South. The ratio of N to P at Bogue Chitto
averaged 10 by weight and 22.1 by molar ratio, and showed no significant trend over time.
Pearl River at Bogalusa had an average ratio of 9 by weight and 19.9 by molar ratio, also
with no temporal trend. The mean N-to-P molar ratio for Bogue Lusa Creek was 37.6,
equivalent to 17 by weight. At this station the annual mean N-to-P ratios showed highly
significant, positive temporal trends.
Nutrient Fluxes
Water flux (discharge) in the Pearl River at Bogalusa was typically three or more
times the discharge measured in the Bogue Chitto River at Bush. Figure 4-7 shows strong
seasonal peaks coinciding with spring rains. Both stations recorded a large flood in early
1980. Turbidity levels were somewhat higher at the Pearl River-Bogalusa site than at the
Bogue Chitto site, but the range of values is the same (Figure 4-8a). TP concentrations
were nearly always below 0.15 mg P I"1 at both sites, except for a high concentration peak
in mid-1979 at Pearl River-Bogalusa and in mid-1981 and late 1983 at Bogue Chitto
(Figure 4-8b). TKN concentrations from the Pearl River-Bogalusa station were usually
higher than those from the Bogue Chitto and showed a period of unusually high values
between 1979 and 1982. The highest TKN concentration - 4 mg-1*1 -was observed at the
Bogue Chitto site (Figure 4-8c). Interestingly, concentrations of TP, TKN, and turbidity
in the two rivers are comparable (in spite of disparate drainage basin sizes), and the Pearl
River-Bogalusa discharge is generally three to five times that at the Bogue Chitto.
Instantaneous nutrient fluxes in these two streams, shown as kg P*day kg
N-day'l- and millions of NTU-day follow the same general pattern as the discharge
data (Figure 4-9), One pervasive pattern in the daily flux values, particularly at the Pearl
River-Bogalusa station, is the seasonal peak coinciding with the spring freshet. At other
times of the year nutrient fluxes were small. The Bogue Chitto flux data show episodic
115

-------
I
I	I
II	¦
TP
0 . 8
0 . 7
0 . 6
0 . 5
0 . 4
0 . 3
0 . 2
0.1
0	. 0
01	J AN 7 0
TP
1 . 0
0 . 0
0 . 8
0 . 7
0 . 6
O . S
0 . 4
0 . 3 -hi IXI
3 10EC74
30DEC79
DATE .
280EC84
27DECB9
¦
i n
0 . 2
0 . 1
0.0
01J AN70
TP
O . 40
0 . 33
0 . 30
0.25
O . 20
0.15
0.10
0 . 05
* * 1
310EC74
30DEC79
DATE
28DEC84
270ECB9
0 . 00
t	«
.« ' « "«
01 J AN 7 0
3 10EC74
30DEC79
DATE
2B0EC84
270EC89
Figure 4-5. Absolute TP concentrations over time for Ross Bamett North (a) and South
(b) and Bogue Lusa Creek at Bogalusa (c). Both Ross Bamett North and
South exhibited significant decreases over time. The trends over time for
the Bogue Lusa Creek station were insignificant.
116

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TKN
1 . 6
1
1
1
0
0
0
0
4
2
O
a
6
4
2
0.0
01 J AN 7 0
TKN
2 ¦ 0
1
1
1
1
1
0
0
0
0
0.0
0 1 JAN70
TKN
4-
%
I
t a
« t
* « i
-i i 		7! * , / *
¦Vi>* ''I *«
3 1DEC74
30DEC79
DATE
2BDEC84 27DECB9
31DEC74
30DEC79
DATE
26DEC84 27DEC89
3
1
w 	I			I	I
01JAN70 31DEC74 30DEC79 26DECS4 270EC89
DATE
Figure 4-6. Temporal trends in TKN concentrations over the period of record for three
stations in the Pearl River basin. TKN increased over time at both Bogue
Lusa Creek (a) and Pearl at Bogalusa stations (b). Bogue Chitto at Bush
has an insignificant slope over time (c).
117

-------
i- 3000
1 9 74
LOWER PEARL
BOGUECHfTTO
r 3000
-2000
-1000
Figure 4-7. Water flux (discharge) in the Pearl River at Bogalusa and in the Bogue
Cbitto River at Bush. The strong seasonal peaks coincide with spring rains.
118

-------
Figure 4-8. Turbidity (a), TP (b), and TKN (c) levels in the Pearl River at Bogalusa and
the	Bogue Chitto River at Bush.
119

-------
>>
CD
¦o
12000000
3 8000000
z
4000000
x
2
5
o
1974
76
78
A


LOWER PEARL
BOGUE CHITTO
•


1 ,
i
It


1)

Aa, ,
80
82
1200000C
- 8000000
- 4000000
84
86
15000
« 10000
"o
o>
JC
c. 5000 -
x
3
15000
10000
5000
200000
£ 150000
O)
100000
x
2 50000 H
19M
200000
- 150000
- 100000
50000
Figure 4-9. Instantaneous fluxes of turbidity, TP, and TKN in the Pearl River at
Bogalusa, Lower Pearl and the Bogue Chitto River at Bush.
120

-------
high flux events more than regular annual pulses of nutrients. This difference in flux
patterns between the two stations is probably related to the large difference in the drainage
basin sizes of the Pearl and Bogue Chitto rivers as well as differences in land use
characteristics (the Bogue Chitto drainage has the highest percentage of agricultural land in
the Pearl River basin). Both lead to more flashy discharge and episodic nutrient fluxes at
the Bogue Chitto station.
Annual fluxes of turbidity, TP, and TKN at both sites are represented by the area
under the daily flux curves for each year. In most cases, the sampling dates and the
intervals between samplings were different for the Pearl River-Bogalusa and Bogue Chitto
sites. For this reason, annual integrated fluxes were computed for the two sites
independently and then combined for a total mass flux to the Pearl River estuary each year.
When the annual fluxes at each site are compared, an interesting pattern emerges. Most of
the suspended sediment discharged to the estuary is supplied by the Pearl River (Figure 4-
10a), whose annual flux is typically 5-10 times that of the Bogue Chitto River. There is
less difference between TP fluxes at the two sites, and even less in the annual TKN data
(Figure 4-10b and 4-10c). Apparently, the Bogue Chitto River is supplying the estuary
with a disproportionate mass of N, in comparison to the Pearl River (which drains most of
the Pearl River basin).
The total mass flux of suspended sediment, TP, and TKN from the Pearl River to
the estuary, as the sum of the annual fluxes from the Pearl River-Bogalusa and Bogue
Chitto stations, is summarized in Table 4-4. Molar flux ratios of N to P calculated from
these total annual flux data showed values of 10-15 for most years between 1974 and
1985, but ratios were greater than 20 in 1980 and 1981 (Figure 4-11; note that 1974 and
1984 ratios are based on incomplete data sets). On an annual basis, P appears to be the
macronutrient most limiting to aquatic primary productivity in Pearl River basin waters as
they enter the estuarine and nearshore portion of the basin.
DISCUSSION
Undisturbed forested watersheds conserve sediments and nutrients, minimizing
erosion. Riparian forests are often net sinks for sediments and nutrients (Lowrance et al.
1984; Peteijohn and Corell 1984). As a result these stream constituents are usually diluted
by precipitation and by increased streamflow. In contrast, in disturbed watersheds
turbidity and nutrient concentrations generally increase with increasing discharge,
presumably because of erosion from disturbed soil surfaces (Brinson 1988; Smith et al.
1982; Ursic 1965). In the Pearl River basin, the combined analysis of all five stations
121

-------
1500000
A ¦ BOGLECHTTTO
0 LOWER PEARL ^
1000000 -
500000 -
x
3
2
n
19 74 75 76 77 78 79 80 81 82 83 84
Year
3000
B
1974 75 76 77 78 79 80 81 82 83 84
Year
— 30000
19 74 75 76 77 78 79 80 81 82 83 84
Year
Figure 4-10. Annual fluxes of turbidity (a), TP (b), and TKN (c) in the Pearl River at
Bogalusa and the Bogue Chitto at Bush.
122

-------
Table
Year
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
Summary of total annual fluxes of nutrients and materials, through the
sampling stations in the Pearl River at Bogalusa and the Bogue Chitto River
at Bush, to the Pearl River estuary and associated nearshore zone.
Turbidity Flux	TP Flux	TKN Flux
(106 NTU yr1)	(103 MT P yr1) (103 MT N yr^)
145.9
0.535
2.81
906.6
1.747
11.45
663.5
1.555
8.8
605.5
1.975
12.70
243.6
1.157
8.96
775.1
2.246
11.91
1304.7
2.364
29.92
259.6
1.214
10.64
299.3
1.234
5.71
658.4
1.883
10.11
205.4
0.790
13.89
123

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40
74 75 76 77 78 79 80 81 82 83 84
Y*ar
Figure 4-11. Molar flux ratios of N to P calculated from the annual flux data presented in
Table 4-4 from the sampling stations in the Pearl River at Bogalusa and the
Bogue Chitto River at Bush.
124

-------
showed turbidity increasing with flow, perhaps indicating some degree of disturbance
within the basin.
Considering both upland and wetland forest, 63.3% of the Pearl River basin is
forested. According to the results of a study by Omemik (1977) examining the relationship
between watershed land use and water quality, a watershed that is more than 50% forested
has typical stream TP and TKN concentrations of about .034 and .839 mg-1"*,
respectively. The TP for the Pearl River basin ranged up to 1.72 mgl"*, with an average
of 0.087 mg l"1. The average TKN concentration was 0.65 mgl"1, ranging from 0.01 to
7.1 mg-1"1. Thus, based on forest cover, TP was higher than expected from Omemik's
(1977) analysis, but TKN was within the expected range.
For the period of record the molar N-to-P ratio averaged 19.9 (with a range of
15.5-26.2). Based on the N-to-P ratio of living plant tissue, a molar ratio of 10-15 reflects
a balanced ecosystem. Below that ratio N is limiting; above it, P is (Hecky and Kilham
1988). This indicates that P is probably the limiting nutrient to phytoplankton primary
production in the Pearl River basin. This generalization must be qualified, however,
because these ratios indicate the relative abundance of total N and P. Along with the ratio
of N to P, it is important to consider the absolute concentrations of N and P. TP averaged
slightly below the 0.1 mg l"1 EPA standard, but was well above the concentration
expected from the percentage of forest cover. TKN concentrations are below the value
predicted by Omernik (1977). Since 1984 the annual mean ratio has been higher than in
previous years (-25.2 on a molar basis). This reflects both the slight increase in TKN and
the decrease in TP in the Pearl River basin. In addition to total forest cover and land use in
the watershed, water quality is also affected by the percentage of streams with riparian
buffer strips. Numerous studies (Lowrance et al. 1984; Peteijohn and Corell 1984) have
found that forested riparian strips effectively filter P, N, and sediments from runoff
entering streams. Riparian forest buffer strips comprise over 85% of the edges of the Pearl
River and its major tributaries.
Except for Ross Barnett South, the major differences between stations in the Pearl
River basin appear to be related to the percentage of forest cover (or conversely,
agricultural land) in the sub-basins where the data were collected. The two southernmost
stations, the Pearl River at Bogalusa and the Bogue Chitto at Bush (Figure 4-1) had the
least (proportionally) forest cover and the most land in agriculture (Table 4-3). These were
the only stations with positive turbidity on flow regression slopes (Table 4-2). They had
the highest mean TKN concentrations, and the Bogue Chitto station also had the highest
mean TP concentration. The value of 34% in agricultural land for the lower Pearl sub-
basin probably underestimates disturbance in the watershed above the Pearl River station at
125

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Bogalusa. This station is about midway up the sub-basin, downstream from most of the
sub-basin agricultural land. The influence of the large lower Pearl River swamp between
Bogalusa and the Gulf of Mexico could not be evaluated.
Although TP concentrations at the Ross Bamett South station generally are
representative of stations with forested watersheds (this subwatershed is 70% forested), it
is likely that water quality at this station reflects the management of the Ross Bamett
Reservoir more than land use in the watershed.
The Bogue Lusa Creek site exhibited anomalous trends compared to the other four
sites. Only 3% of the TP values exceeded 0.1 mg-H; the mean TP concentration was 0.04
mg l"l, and associated with this was a high 37.6 molar N-to-P ratio. The site is located in
the lower Pearl River sub-basin, as is the Pearl at Bogalusa station, but the stream is small,
draining only a small portion of the sub-basin. We were not able to determine the
boundaries of, and land use on, this small drainage.
CONCLUSIONS
Although the water quality patterns in the Pearl River basin as a whole show
characteristics of a basin experiencing some disturbance, the overall assessment of the Pearl
River basin based on water quality is positive. The watershed is maintaining acceptable
water quality based on a 0.1 mgl"* TP criterion (U.S. Environmental Protection Agency
1976). Yet, there is only limited understanding of what these concentration levels and
trends indicate, what the significance of extreme values is, and the standards that should be
set. Gosselink and Lee (1989) noted the need for comparative cumulative impact studies
that consider a broad range of ecosystems, from pristine to highly degraded. At the
national level, Omemik's (1977) study provides excellent comparative data. The highly
degraded Tensas River basin in northeastern Louisiana offers another excellent comparison
to the relatively undisturbed Pearl River basin (Gosselink et al. 1990). Historically, over
90% of the 1,000,000-ha Tensas study area was bottomland hardwood forest. Now 85%
of the land is in agricultural production, and 84% of all streambanks are bordered by
agricultural fields. The impacts caused by the accompanying loss and fragmentation of the
forests, probably combined with heavy crop fertilization, were evident in the analyses of
water quality. Basin wide, 96% of the TP values exceeded the 0.1 mg-1"* criterion. At the
three stations analyzed, highly significant and positive relationships existed between
turbidity and flow. While TKN concentrations were within Omemik's (1977) predicted
range, TP values were up to an order of magnitude greater than his predicted 0.16 mg l'l
(based on land cover type). Molar ratios of N to P ranged from 6.6 to 15. These ratios,
along with the high TP levels, indicated that N, and not P, may be limiting aquatic
126

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productivity in the Tensas basin (Childers and Gosselink 1990). Apparently agricultural
land uses in the Tensas basin contribute high sediment and nutrient loads to surrounding
streams and rivers, and arc therefore a major influence on the quality of water in the basin.
To some degree, the sub-basins in the Pearl River follow the trends of the Tensas
basin, although the Pearl River basin stream nutrient concentrations are at the low end of
the range of reported values. Generally, those sub-basins with the highest percentage of
land in agricultural production have the highest turbidity, TP, and TKN concentrations
(Table 4-3).
On the basis of the results of the water quality analyses and the comparison with the
Tensas basin study, the Pearl River basin water quality is within acceptable limits. Of the
Pearl River watershed, 64% is upland and wetland forest, and only 31% is agricultural. Of
the major tributaries feeding the Pearl River, 85% have streamside forested buffer strips.
Although the basin's present water quality is acceptable, it is important to recognize that
certain areas in the basin reflect disturbance and to address this in the goal-setting and
management planning phases.
127

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REFERENCES
Brinson, M. M. 1988. Strategies for assessing the cumulative effects of wetland alteration
on water quality. Environmental Management 12:665-662.
Childers, D. L., and J. G. Gosselink. 1990. Assessment of cumulative impacts to water
quality in a forested wetland landscape. Journal of Environmental Quality 19:454-
463.
Gosselink, J. G., and L. C. Lee. 1989. Cumulative impact assessment in bottomland
hardwood forests. Wetlands 9:83-174.
Gosselink, J. G., G. P. Shaffer, L. C. Lee, D. M. Burdick, D. L. Childers, N. C.
Leibowitz, S. C. Hamilton, R. Boumans, D. Cushman, S. Fields, M. Koch, and
J. M. Visser. 1990. Landscape conservation in a forsted wetland watershed: can
we manage cumulative impacts? Bioscience 40 (9):in press.
Hecky, R. E., and P. Kilham. 1988. Nutrient limitations of phytoplankton in freshwater
and marine environments: a review of recent evidence on the effects of
environment. Limnology and Oceanography 33 (4.2):796-822.
Hirsch, R. M., J. R. Slack, and R. A. Smith. 1982. Techniques of trend analysis for
monthly water quality data. Water Resources Research 18 (1):107-121.
Lowrance, R., R. Todd, J. Fail Jr., O. Hendrickson, R. Leonard, and L. Asmussen.
1984. Riparian forests as nutrient filters in agriculture watersheds. Bioscience
34:374-377.
Murphree, C., C. Mutchler, and L. McDowell. 1976. Sediment yields from a Mississippi
delta watershed. Pages 1-99 to 1-109 in Proc. Third Inter-agency Sedimentation
Conf., Water Resources Council, Washington, D.C.
Omernik, J. M. 1977. Nonpoint source - stream nutrient level relationships: a nationwide
study. Corvallis Environmental Research Laboratory, Office of Research and
Development, U.S. Environmental Protection Agency, Corvallis, Oreg. EPA-
600/3-77-105.
128

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Peteijohn, W. T., and D. L. Corell. 1984. Nutrient dynamics in an agricultural
watershed: observations on the role of a riparian forest Ecology 65 (5): 1466-
1475.
SAS Institute, Inc. 1985. SAS User's Guide: Statistics, Version 5. SAS Institute, Cary,
N.C.
Siegel, S., and N. J. Castellan. 1988. Nonparametric statistics for the behavioural
sciences. McGraw-Hill, New York.
Smith, R. A., R. M. Hirsch, and J. R. Slack. 1982. A study of trends in total
phosphorus measurements at NASQAN stations. Water Supply Paper 2190. U.S.
Geological Survey, Washington, D.C.
U.S. Environmental Protection Agency. 1976. Quality criteria for water. U.S.
Environmental Protection Agency, Washington, D.C. 256 pp.
Ursic, S. 1965. Sediment yields from small watersheds under various land uses and
forest owners. Misc. Publ. 970: 41-52. Proc. Inter-agency Sedimentation Conf.,
U.S. Department Agriculture, Washington, D.C.
129

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CHAPTER 5: FAUNAL DIVERSITY AS AN INDEX IN
CUMULATIVE IMPACT ASSESSMENT-PEARL RIVER
BASIN, MISSISSIPPI AND LOUISIANA
131

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¦yx
,4:
I

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INTRODUCTION
Protection and conservation of the earth's ecosystems arc necessary to prevent
critical loss of environmental quality and wildlife habitat Recent human activities such as
agricultural and urban development (Council on Environmental Quality 1984) have
threatened these ecosystems and led to loss of biological diversity and extinction of species,
deforestation, and wetland loss (Powers and Lee in press). Environmental degradation
results both from large or damaging activities and from the accumulation of many activities
that in sum may have both significant and dramatic impacts. Failure to consider the effect
of these cumulative impacts can lead to gradual depletion or "nibbling" away of our natural
resources (Gosselink and Lee 1987).
Although environmental legislation in the United States requires evaluation of these
cumulative impacts (Council on Environmental Quality 1978), rarely are they investigated
adequately, partly because widely accepted methods and approaches are largely lacking
(Walker et al. 1986). Current regulatory approaches are too often based on criteria specific
to individual sites and projects. Long-term indirect or induced effects that may occur years
after the direct disturbance are not considered. Effective measurement and management of
ecosystem disturbances require that cumulative impacts be assessed, and that there be a
match between the ecological processes affected and the regulatory measures employed
(National Research Council [NRC] 1986).
In order to effectively evaluate cumulative impacts and implement management
goals, indices are needed for assessing the past, present, and future projected conditions of
a particular landscape. This chapter considers one such index of landscape health: biotic
diversity. Indices of biotic diversity for large areas are difficult to devise. Not only are
long-term data for trend analyses limited, it is difficult to develop biotic indices that
integrate over a landscape-level assessment unit in the same way that a water quality station
at the lower end of a watershed does. Also, interpretation of existing data is difficult
because of the complexity of the biotic food web and biotic adaptation to the environment
(Gosselink and Lee 1987). For these reasons, several indices incorporating both site-
specific and historic trend data will be used to look at faunal diversity in the Pearl River
basin in Mississippi and Louisiana.
Gosselink and Lee (1987) cite historical changes in species richness, indicator
species, and endangered and threatened species as three measures of biotic diversity.
These three "barometers" of landscape health will be examined at a landscape level using
existing data bases for the Pearl River basin, a 22,688-km2 watershed comprising 27
counties/parishes. Temporal change in bird species richness and composition in relation to
habitat will be considered in detail, principally because bird counts are the most
133

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comprehensive biotic data available for this basin. Some limited data on fishery resources
in the basin will also be examined.
TEMPORAL CHANGES IN BIRD SPECIES RICHNESS
Introduction
Although factors other than habitat influence size and species composition of bind
communities (e.g., geographic location, pioneering ability, competition, population levels,
climatic factors [Kendeigh 1944]), habitat clearly has an impact and can be readily
measured (Weller and Spatcher 1965). Research investigating relationships between
habitat and number and composition of bird species suggests that variables such as habitat
size, structure, and floristic components are closely related to species richness and
composition (Anderson 1981; Bond 1957; Burdicketal. 1989; Butcher etal. 1981;
Diamond 1975; Galli et al. 1976; Harris 1984; Whitcomb et al. 1981). The following
section concerns methods and preliminary results of an analysis of bird species richness
and composition in the basin. The relationship between land cover and the above variables
will be examined in an effort to (1) assess faunal diversity in the basin and (2) determine
the reliability of using long-term and land cover data in cumulative impact analyses at the
watershed scale.
Methods
Although bird resources are better documented than other wildlife groups in the
basin, the data at best are fair. Two long-term data sets showing changes in bird species by
area were used to analyze bird populations in the basin: the National Audubon Society's
Christmas Bird Counts (CBC) and the U.S. Fish and Wildlife Service's Breeding Bird
Surveys (BBS).
The CBC involves observers identifying birds within a 24-km-diameter circle with
a standardized midpoint. The count occurs over a period of 24 h once a year at Christmas.
One CBC site, Jackson, is located within the Pearl River basin (Figure 5-1).
BBS routes consist of 50 stops 0.8 km apart and are run along a standardized route
(40 km) one morning in June at the height of the breeding season. Birds seen or heard at
each stop are counted for 3 min during a 4-1/2 h period. Five BBS sites in the study area
were analyzed: Cybur, Lucien, Columbia, Lake, and Lacombe (Figure 5-1).
Analysis consisted of standardizing CBC data by dividing bird counts by the number
of observer group (party) hours. Standardized bird counts for both BBS and CBC were
then regressed against time. Birds sighted less than six times over each survey period were
134

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Tf«*
Hf MISS.



\ J*
4
> f


u
Mississippi
Louisiana
Christmas Bird Count Site
J Jackson (1904,1960-87)
Breeding Bird Survey Routes
8 Lacombe (1967-73)
Cybur (1968-69,1971-73,1977-82)
Lucien (1974-78,. 1987)
Columbia (1974-76,1978-84)
Lake (1966-70,1972,1979-80,1987)
10 20 30 40
Kilometers
Figure 5-1. Bird survey sites within the Pearl River basin.
135

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eliminated from the analysis. Habitat preferences were identified by Dr. Robert Hamilton,
Louisiana State University, School of Forestry, Wildlife, and Fisheries, for each species
analyzed. These habitat categories, listed below, were taken from existing literature:
-	water
-	swamps and wet edges
-	marshes
-	fields
-	forest edges
-	forest in general
-	forest open canopy
-	forest closed canopy
Forest closed canopy species primarily utilize closed canopy forests, as opposed to
edge or field habitats. Edge/field species are primarily associated with "edge" habitat,
clearings, or agricultural fields. Appendix C reports diversity trends over time by habitat
preference for CBC and BBS sites.
Temporal change in bird species richness by habitat was compared to change in
land cover from 1973 and 1987 land cover maps (see Chapter 2). Land cover classes were
digitized within a 0.40-km corridor on either side of the five 40-km BBS routes and within
a 24-km-diameter circle for the Jackson CBC site (Table 5-1; Appendix D). Maps of
selected bird routes are included in Appendix D.
BBS periods at three of the five sites coincided with the 1973 land-use data. Mean
numbers of bird species and percentages of forest or field/edge species observed at each
site during 1968, 1969, and 1972 surveys (the only years to correspond across sites) were
calculated to yield averages over a five-year span (1968-1972). Percentage species
richness by habitat category was then compared across the three sites and related to
percentage of the corridor in certain cover classes (in 1973) for each site.
Results
The BBS's were conducted intermittently for most routes within the study area
(Figure 5-1). The Lake and Cybur sites both increased in species richness in general
(Table 5-2) and in particular increased in birds that prefer forest open canopy and in field
and edge birds. The Cybur site showed the strongest trends, with an 11.5% increase
136

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Table 5-1. Results of land cover for bird survey areasa digitized from 1973 and 1987 land
cover maps (see Chapter 2) for areas covered by bind surveys.
Site
Sub-basin
Land-coverb
1973
ha
%
1987
ha
%
Jackson
Pelahatchie
agricultures
12332
30
8722
21
(CBC)
Creek
forestd
16295
39
20366
49


waters
11019
27
10794
26
Columbia
Lower Pearl
agriculture
1160
33
1066
31

Basin
forest
2201
63
2347
67


water
97
3
30
1
Lucien
Bogue Chitto
agriculture
1285
38
1116
33

River
forest
2024
59
2239
66


water
54
2
10
0
Lacombe
Bogue Chitto
agriculture
391
12
586
17

River
forest
2925
86
2499
74


water
29
1
234
7
Lake
Tuscalameta
agriculture
1300
38
1363
40

Creek
forest
1520
44
1748
51


water
348
10
49
1
Cybur
Lower Pearl
agriculture
1829
52
2446
70

River
forest
1595
46
961
28


water
61
2
29
1
a Land cover digitized within a 0.40-km corridor on either side of the five 40-km BBS
routes and within a 24-km-diameter circle for the Jackson CBC site,
b Urban and barren/other land cover categories not included,
c Agriculture/grassland.
d Coniferous forest + mixed forest + deciduous forest + bottomland hardwood forest,
e Water + forested wetland + nonforested wetland.
in birds that preferred field/edge habitat corresponding to an 18% increase in agricultural
habitat There was a general trend of increasing species density at this site for Mourning
Dove (Latin names for all species are given in Appendices B and C), Red-winged
Blackbird, and American Crow, all common field and edge species that use agricultural
fields extensively (Figure 5-2). Two of the three species decreasing at the Cybur site use
upland forest habitat (Chimney Swift and Black Vulture); all three decreasing species
(Common Nighthawk plus the other two) also utilize bottomland hardwood forests.
Forest land cover at the Cybur site decreased by 18% (from 46% to 28%); bottomland
137

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Table 5-2.' Summary of bird species regressed against time.
Bird Sites3
Species
Jackson Columbia
Lacombe
Lake
Lucien Cybur
Total # species recorded
129
75
57
69
71
61
# species increasedb
19
7
8
8
6
11
% species increased
14.7
9.3
14.0
11.6
8.5
18.0
# species decreased
19
12
7
1
7
3
% species decreased
14.7
16.0
12.3
1.4
9.9
4.9
# species showing no trend
91
56
42
60
58
47
% species showing no trend
70.5
74.7
73.7
87.0
81.7
77.0
Species recorded bv bird habitat






Total # water species^
40
6
1
3
0
6
Total % water species
31.1
7.9
1.8
4.3
0.0
9.8
# water species increased
7
1
0
0
0
0
% water species increased
5.5
1.3
0.0
0.0
0.0
0.0
# water species decreased
0
1
0
0
0
0
% water species decreased
0.0
1.3
0.0
0.0
0.0
0.0
# water species showing no trend
33
4
1
3
0
6
% water species showing no trend
25.6
5.3
1.8
4.3
0.0
9.8
Total # forest species^
49
46
38
45
49
36
Total % forest species
38.0
61.2
66.8
65.1
69.0
58.9
# forest species increased
4
3
8
7
2
4
% forest species increased
3.1
3.9
14.1
10.1
2.8
6.5
# forest species decreased
13
7
3
1
5
3
% forest species decreased
10.1
9.3
5.4
1.4
7.0
4.9
# forest species showing no trend
32
36
27
37
42
29
% forest species showing no trend
24.8
48.0
47.3
53.6
59.2
47.5
Total # field speciese
40
23 .
18
21
22
19
Total % field species
31.1
30.7
31.6
30.4
31.0
31.1
# field species increased
8
3
0
1
4
7
% field species increased
6.2
4.0
0.0
1.4
5.6
11.5
# field species decreased
6
4
4
0
2
0
% field species decreased
4.7
5.4
7.1
0.0
2.8
0.0
# field species showing no trend
26
16
14
20
16
12
% field species showing no trend
20.2
21.3
24.5
29.0
22.6
19.6
a Survey period for sites:
Jackson, 1904, 1960-1987; Columbia, 1974-1976,1978-1984; Lacombe, 1967-1973;
Lake, 1966-1970, 1972, 1979-1980, 1987; Lucien, 1974-1978,1987; Cybur, 1968-
1969, 1971-1973,1977-1982.
b Significant increase = P < .10.
c Total water = water + swamp + marsh bird habitat preferences,
d Total forest = forest + forest closed canopy + forest open canopy bird habitat
preferences.
e Total field = field + edge bird habitat preferences.
138

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a.
>
9
a
I
r
V.
e
e
00 -

¦100
1
O
, CO

-80
¦


60 -

-60 *
¦
Ab /
jt
40 -

-40
¦
«/ I
K
20 "
n -
ftr 4
-20
-n
60
70	80
Year
90
¦ Mourning Dove
• % Agriculture
b.
100
g H Red-wg Bkbird
^ ~ % Agriculture
K
Year
C.
100
100
-60
•>
*

3

fe.
-40
<

K
¦ Am Crow
* % Agriculture
Figure 5-2. Standardized abundance of field/edge species and percentage change in
agricultural land cover over time, Cybur site (1968-1969,1971-1973,1977-
1982).
139

-------
hardwoods decreased from 11% to less than 1% (Figure 5-3, Appendix D).
The Lake site showed a 10% increase in forest bird species compared to a 7%
increase in forest land cover. Eight of the surveyed species increased, one of which prefers
forest habitat, and six, forest open canopy habitat. Figure 5-4 illustrates the increase for
two of these species in relation to forest habitat. The one decreasing species, Pileated
Woodpecker, prefers forest closed canopy. One edge/forest species (Carolina Chickadee)
at the Lake site increased, compared to a 2% increase in agricultural land cover.
The Lacombe site was not surveyed after 1973; therefore no comparison can be
made with the 1987 land cover data.
Very little temporal change in land cover occurred at the Columbia site during 1973-
1987 (agriculture decreased by 2%; forest increased by 4%). Seven bird species increased
in density; twelve decreased. In general, both field/edge birds and forest birds, particularly
forest open canopy birds, decreased. Agricultural land cover at the Lucien site showed a
5% decrease; forest increased by 7%. Species compositions by habitat at this site did not
correspond to land cover-birds that preferred field habitat increased by 6%; forest birds
decreased by 7%.
Analysis of 29 years of CBC data for the Jackson site (1904,1960-1987) revealed
no particular trends in species richness by habitat and land cover from 1973 to 1987 (19
species increased, 19 decreased). Additional land-use data for the 1960s is needed to more
accurately correlate change over time for both indices.
The mean number of bird species from three years (1968,1969,1972) of BBS's
from each of three routes (Lacombe, Lake, and Cybur) were compared with percentage
land cover adjacent to each route in 1973 (Table 5-3). The percentage of agriculture along
each route decreased from Cybur (52%) to Lake (38%) to Lacombe (12%). Field/edge bird
species (as percentage of total bird species recorded) also decreased from Cybur (62%) to
Lake (53%) to Lacombe (38%). Forest land cover and forest birds followed the opposite
trend, increasing from Cybur (46% forest land cover/38% forest bird species) to Lake
(51% forest land cover/47% forest species) to Lacombe (86% forest land cover/61% forest
species).
140

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a.
M
c
>
in
«>
.e
o
o
«
m
K
B Chimney Swift
~ %BLHF
b.
>
*
e
o
E
E
o
o
V-
o
o
o Cm Nighthawk
~ % BLHF
Figure 5-3. Forest species abundance and percentage change in bottomland hardwood
forest land cover over time, Cybur site (1968-1969,1971-1973,1977-1982).
141

-------
a.
L.
O
*
B Red-bell. Wood
• % Forest
b.
©
OC
%
o
k.
*
£
<
V)
*>
k.
e
u.
*
B Am. Robin
• % Forest
Figure 5-4. Forest open canopy species abundance and percentage change in total forest
land cover over time, Lake site (1966-1970,1972,1979-1980,1987).
142

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Table 5-3. Percentage of bird species by habitat preference (from three BBS routes, 1968-
72 means) compared to percentage land cover adjacent to routes in 1973.
	Routes	
Lacombe Lake	Cybur
Longitude/latitude 89° 54'E 30° 16'N 89° 8' E 32° 33' N	89° 48' E 30° 42' N
% Agriculture 12 38	52
% Field/edge speciesa 38 53	62
% Forest 86 44	46
% Forest species3 61 47	38
a Percentage of total bird species recorded (1968-1972 mean).
Wading Birds
Wading bird resources within the basin are not well known. The two known
breeding colonies are in riparian woodland in Newton County, Mississippi, and in a tupelo
gum-bald cypress (Nyssa aquatica/Taxodium distichum) swamp and adjacent marsh in the
White Kitchen Tract, St. Tammany Parish, Louisiana. The latter colony site is used yearly
by the only pair of nesting Bald Eagles in the basin (U.S. Fish and Wildlife Service
[USFWS] 1981).
Waterfowl
Waterfowl use the basin moderately because of its location just outside the main
portion of the Mississippi Flyway and the relatively small acreage of permanently flooded
wetland. Wood Duck and Mallard (Latin names are given in Appendix E) use flooded
bottomland hardwood areas extensively, and most hunting activity occurs in these areas.
Gadwall, Pintail, Green-winged Teal, and Ring-necked Duck are also harvested (USFWS
1981; U.S. Army Corps of Engineers [USACE] 1970).
TEMPORAL CHANGES IN FISH AND OTHER WILDLIFE
SPECIES RICHNESS
Fisheries
The Pearl River basin supports a diverse fish fauna; approximately 133 species are
known for the area (Appendix E). The lower portion of the basin is heavily used by both
recreational and commercial fishermen and is considered important to finfish and shellfish
production. Recently the USACE estimated (based on sparse data compiled on species
143

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abundance, landings, and value) that the basin produces over 7.9 kg of harvestable
estuarine fish and shellfish per hectare, having a value of over $22.50 per hectare (Table 5-
4). Finfish harvested by both recreational and commercial fishermen include red drum (red
fish), spotted seatrout, Atlantic croaker, spot, and blue and channel catfish. Commercially
important shellfish include brown and white shrimp, blue crab, and oysters.
Table 5-4. Estimated production value of finfish and shellfish in the Pearl River basin
based on abundance of estuarine species and landings (US ACE unpublished
data).

Abundance
Value
Vaiue
Taxa
(kg/ha)
($/ha)
($/ha)
Gulf menhaden
0.38
0.0825
0.0314
Red drum
0.38
1.5129
0.5749
Atlantic croaker
0.38
0.5607
0.2131
Spot
0.38
0.4410
0.1676
Channel catfish
0.38
1.0805
0.4106
Blue catfish
0.38
1.0805
0.4106
Brown shrimp
2.72
4.1234
11.2156
White shrimp
1.89
4.1234
7.7932
Blue crab
0.62
0.7953
0.4931
Oysters
0.31
3.3075
1.0253
Other (crabs)
0.04
5.0274
0.2011

7.86 kg / ha

$22.5365/ha
Abundance data for fish populations in the basin as a whole are lacking. Some data
are available from the Mississippi Department of Wildlife Conservation for the Ross
Barnett Reservoir; a subsystem within the basin. The reservoir is considered atypical of
the basin as a whole, however, because of its conversion from a riverine system to a
reservoir in 1964 (USACE 1970).
144

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Uncorrected 1963-1987 catch data (uncorrected for effort; raw kilograms from
National Marine Fisheries Service unpublished data, Hydrologic Units 12.1 and 12.2) for
selected estuarine species in waters within (Lake Borgne) and adjacent to (Chandeleur
Sound) the basin are available. Some trends in these data are noteworthy. For example,
examination of catch data (kilograms) of red drum and blue crab, when plotted against year
on the abscissa, indicate that catch has increased steadily since the mid-1970s, even though
the data are quite variable (Figure 5-5). Where equivalent data were available (e.g.,
Atlantic croaker, spotted seatrout, oysters), other estuarine species showed similar trends.
The dramatic increase since 1982 in kilograms of red drum landed reflects the increase in
demand, probably due in part to the changing fishery status (game vs. nongame species) of
red drum in other northern Gulf of Mexico (other than Louisiana) states and the developing
national popularity of "cajun" food (i.e., blackened red drum). However, trends in these
data must be interpreted with caution since no effort data are available.
The catch of shrimp (brown and white shrimp combined) in waters adjacent to the
basin has also increased dramatically since the mid-1970s (Figure 5-6). These data for
shrimp are perhaps more revealing since some effort data, given as the number of shrimp
fishing trips per year, are available for Hydrologic Units 12.1 and 12.2 (Figure 5-7).
These effort data can be combined with the shrimp catch to produce a coarse estimate of
catch per unit effort (CPUE).
Effort given as number of fishing trips per year (1963-1987) appears to have been
high in the mid-1960s, decreased in the 1970s, and then increased in the 1980s when catch
increased gready. Catch per unit effort has increased steadily since the 1960s, but has
fluctuated widely since 1980 (possibly a sign of near maximum harvest of a variable
resource) (Figure 5-8). To quantify this trend, the CPUE was regressed on Year using a
linear model. The regression was highly significant (P < 0.0001; r^ = 0.59), and the
relationship suggests that shrimp catch per unit effort has increased dramatically by nearly
13% per year over the 24 years between 1963 and 1987 (Figure 5-8).
As a final examination of these limited shrimp data, the value in dollars (not
standardized to 1989 dollars) of the shrimp catch from 1963 to 1987 was regressed on the
CPUE over the same period. The regression was again highly significant (P < 0.0001;
= 0.61) and suggests that the value of shrimp is increasing exponentially relative to the
linear increase in CPUE.
Anadramous Fish
Anadramous fish resources, extremely important both economically and
ecologically, continue to be depleted along the Pacific, Atlantic, and Gulf coasts (USFWS
145

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H
<
u
s
K
El
O
U
St
1960
1970
1980
1990
YEAR
E
•
Bt
J*
s
u
H
<
u
<
fi£
u
3
es
1960
1970
1980
1990
YEAR
Figure 5-5. Uncorrected catch (raw weight) of red drum and blue crab in waters adjacent
to the Pearl River basin (Hydrologic Units 12.1 and 12.2) between 1963 and
1987 (NMFS unpubl. data).
146

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C/2
0
1960
1970
1980
1990
YEAR
Figure 5-6. Uncorrected catch (raw weight) of shrimp (brown and white combined) in
waters adjacent to the Pearl River basin (Hydrologic Units 12.1 and 12.2)
between 1963 to 1987 (NMFS unpubl. data).

-------
200
^ 150-
b
y = - 7139.5 + 3.6464x RA2 = 0.596
b
fih
Ed
H
<
U
H
O 100-
£ 50"
0
1960
1970
1980
1990
YEAR
Figure 5-8. Catch per unit of effort for shrimp (brown and white combined) in waters
adjacent to the Pearl River basin (Hydrologic Units 12.1 and 12.2) regressed
on time (1963-1987) (NMFS unpubl. data).
1981). Species of anadramous fish found in the Pearl River system include Atlantic
sturgeon, skipjack herring, striped bass, Alabama shad, and threadfin shad. It is not
known conclusively if these fish spawn in the basin; however there are potential blocks to
anadramous fish runs along the lower Pearl in the form of weirs constructed by the
USACE (USFWS 1981).
There are few wildlife species other than birds in the basin for which long-term
species composition and population level data exist. In general, the basin supports high
wildlife diversity (Appendix E). Species hunted as game include white-tailed deer,
squirrels, and rabbits. Game birds are Turkey, Mourning Dove, Bobwhite, waterfowl,
Woodcock, and Snipe. Common nongame mammals include the eastern chipmunk, cotton
mouse, rice rat, hisped cotton rat, and pine vole. Furbearers include mink, raccoon,
muskrat, fox, bobcat, opossum, river otter, nutria, and beaver. (USFWS 1981).
Generally, bottomland hardwood forests and their edges support the highest density of
animals, and are considered the greatest asset to deer, squirrel, and furbearers. Prime areas
are the Lobutcha and Yockanookany bottomlands and the Pearl bottomlands near the
confluence of Tuscalameta Creek (USACE 1970).
Other Wildlife
148

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INDICATOR SPECIES
Indicator species can be defined as top carnivores with large ranges whose presence
or absence is an index of landscape integrity (Gosselink and Lee 1987). Time series data
for indicator species are generally not available; however the Mississippi Department of
Wildlife Conservation does have general status and population data for raptors, shown in
Table 5-5. Densities of approximately one-half the raptors listed for the basin are
unknown. Densities appear to be stable or increasing (Bald Eagle) for the remainder; no
populations are listed as decreasing.
ENDANGERED AND THREATENED SPECIES
Endangered species are those in danger of extinction throughout all or a significant
portion of their range. Threatened species are those likely to become endangered within the
foreseeable future (USFWS 1978). Table 5-6 lists threatened/endangered species for the
study area. Habitat preference for these species is given in Appendix E. Figure 5-9 plots
species distribution within the basin. Brown Pelicans are limited to coastal bays in the
Pearl River basin. The Bald Eagle, occurring in the basin both as a transient and as a
breeding species, has been recorded near the Ross Bamett Reservoir in the winter and
nests in the lower basin in the White Kitchen Tract The Red-cockaded Woodpecker is
found sporadically over the basin; the major cause for its decline has been the conversion of
mature pine stands to pine monoculture with shorter rotations than are required for
maintenance of colony areas (USFWS 1981). Historical ranges of both the Ivoiy-billed
Woodpecker and Bachman's Warbler include the basin, but there are no specific records of
their occurrence. The Florida cougar and red wolf once ranged over the area, but are
probably now extirpated from the basin. The ringed sawback turtle, rainbow snake, and
crystal darter occur in the lower reaches of the Pearl River floodplain.
DISCUSSION AND CONCLUSIONS
Lack of systematic, long-term data prohibited analysis of species richness and
composition in relation to habitat for all wildlife groups except birds and fish. The only
quantitative data available for nongame bird resources are the BBS and CBC. The BBS's
have been conducted intermittently for different routes, and thus the survey period of
record didn't always match across sites, coincide with land use data compiled in 1973 and
1987, or cover enough time for statistical analyses. BBS's are performed from a road,
and therefore interior forest species are not sampled as effectively as edge species. CBC's
14o

-------
are conducted at different hours (over a 24-h period) and exclude neotropical migrants,
which are generally not present during the sampling season.
Abundance data collected for effort for fish populations within the basin are
generally lacking or are in an insufficient time series for statistical analyses. The available
shrimp effort data must be viewed with caution since they represent effort not standardized
to gear type, length of fishing trip, number of fishermen, or technological advances in the
fishing fleet.
Table 5-5. Raptors known to frequent the Pearl River basin (from Mississippi Department
of Wildlife Conservation, unpublished data).
Species
Statusa
Population Trend*5
Black Vulture
C
S
Turkey Vulture
U
S
Osprey
c,u
S
American Swallow-tailed Kite
R
S
Black-shouldered Kite
R
U
Mississippi Kite
C,U
S
Bald Eagle
R
I
Northern Harrier
C,U
S
Sharp-shinned Hawk
U,R
U
Cooper's Hawk
U,R
U
Red-shouldered Hawk
C
S
Red-tailed Hawk
C
S
Broad-winged Hawk
C
U
Rough-legged Hawk
R
u
Swainson's Hawk
R
u
Golden Eagle
U
u
Crested Caracara
R
u
American Kestrel
C
S
Peregrine Falcon
R
u
Merlin
U
u
Common Barn-Owl
C
S
Barred Owl
A,C
S
Great Homed Owl
C
s
Eastern Screech-Owl
C
S
Short-eared Owl
R
u
Long-eared Owl
R
u
Northern Saw-whet Owl
R
u
Burrowing Owl
R
u
a C = Common, U = Uncommon, R = Rare, and A = Abundant.
b S = Stable, U =? Unknown, I = Increasing, and D = Decreasing.
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Table 5-6. Endangered and threatened species of the Pearl River basin (after Mississippi
Natural Heritage Program unpublished data and USFWS 1981)a.

State
Federal
Species
Statusb
Status
Fishes


Atlantic Sturgeon (Acipenser oxtrhynchus)
LE

Frecklebelly Madtom (Noturus munitus)
LE

Crystal Darter {Ammocrypta asprella) .
LE

Reptiles


Ringed Sawback Turtle (Graptemys oculifera)
LE
LT
Rainbow Snake (Farancia eytrogramma)
LE

Eastern Indigo Snake (Drymarchon corals Couperi)
LE
LT
Black Pine Snake (Pituophis melanoleucus)
LE

American Alligator (Alligator mississippiensis)
LE

Gopher Tortoise (Gopherus polyphemus)
LE
LE
Birds


Southern Bald Eagle (Haliaeetus leucocephalus)
LE
LT
Arctic Peregrine Falcon (Falco peregrimts)
LE
LE
Red-cockaded Woodpecker (Picoides borealis)
LE
LE
Brown Pelican (Pelecanus occidentalis)
LE
LE
Mammals


Black Bear (Ursus americanus)
LE

Florida Panther (Felis concolor Coryi)
LE
LE
a Known to have occurred in the Pearl River basin or occurrence is strongly suggested by
geographical range.
b Mississippi status only; there is no official state list of threatened and endangered species
for Louisiana. LE = listed endangered; LT = listed threatened.
Birds
Available BBS survey data, when compared to temporal change in land use over a
15-year period (1973-1987), generally indicated that trends in bird species richness and
composition correspond to changes in land cover. Three of the five BBS sites, when
analyzed separately over each respective survey period, showed a positive relationship
between land cover change and alteration in species richness and composition.
At the Cybur site, an increase in agricultural habitat corresponded to an increase in
field/edge birds. All three decreasing species of birds at this site utilize bottomland
hardwoods, which decreased over 1973-1987.
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Mississippi
Louisiana
III
Brown Pelican
(Pelicaruts occuUmalis)

Atlantic Sturgeon

(Aciptrutr ozyrkynchus)
•
Crystal Darter'
(Ammocrypta asprtlla)
~
Eastern Indigo Snake
(DrymarchoH corais eouptri)
III
Peregrine Falcon
(Falco Pvtgruua)
¦
Rainbow Snake
(Faroneia trytrogramma)
tit
Florida Panther
•••
(Felis concotor coryi)
Gopher Tortoise
(gophtrui potyphtmus)
Ringed Sawback
(iGrapttmys oculifera)
X
Bald Eagle Nest
(Haiiacttus liucephalus)
=
Freckledbelly Madtom
(Nolurus munitui)

Red-cockaded Woodpecker
{Picoidts bortalis)
Black Pine Snake
(Piluophis ntlanotucus lodingi)
•
Black Bear
(Ursus airuriauius)
Figure 5-9. Threatened/endangered species of the Pearl River basin (from Mississippi Depart-
ment of Wildife Conservation and Louisiana Natural Heritage Program, unpub-
lished data).
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The Lake site showed a positive correlation between increasing forest land cover
and bird species that prefer forest habitat, and a smaller increase in agri~ultural land cover
and field/edge bird species.
Two sites, Columbia and Lucien, showed no positive correlation between land
cover and species richness and composition. Possibly the very small changes in land cover
at the Columbia site were a reason for the lack of correlation.
Comparison of BBS data across sites over a three-year period for three routes
within the basin (Cybur, Lacombe, Lake) yielded strong apparent correlations between land
cover and species richness and composition. Mean percentage of forest species observed
per three-year period increased with increases in forest habitat; mean percentage of
field/edge species likewise decreased with decreases in agriculture.
Analysis of CBC data revealed about equal numbers of bird species increasing and
decreasing. We were not able to correlate these changes with land cover changes because
the time periods for land cover analysis (1973 and 1987) did not correspond with the bird
survey period (1904,1960-1987). Additional land use data for the 1960s are needed to
correlate temporal changes in the abundance of particular bird species at this site to land
cover (habitat).
Overall, the limited data suggest that trends in bird species composition and
richness generally correspond to temporal changes in land cover. The changes in bird
species richness and composition in many cases reflect small corresponding changes in
land cover.
Powers and Lee (in press) suggest that a starting point for determining the presence
of balanced indigenous populations is to examine the response of single populations to
changes in habitat. Based on the above analysis, bird data appear to be a useful tool for
evaluating faunal diversity and cumulative impact analysis at the watershed level.
Overall the data are not sufficient to use bird species richness as a blanket indicator
of species richness within the basin or of the health of the basin as a whole; however, the
data do suggest that the basin is relatively stable, at least in terms of bird species richness.
Species abundance either increased or remained relatively stable at five of the six sites
surveyed. Correspondingly, changes in land cover have also been relatively minimal.
Forest decreased in only two of the six sites surveyed, and then by only approximately
10%. Forested wetland remained stable at all sites but Cybur, where nearly all the 1973
bottomland forest was converted to other uses by 1987. Although basinwide changes in
land use and bird species richness and composition are small, they should be monitored to
prevent nibbling away of resources, since minimum habitat requirements for many species
are unknown.
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Fisheries
The limited data available for fish indicate that shrimp catch per unit effort has
increased over the 24-year period of record. The trend suggests that one unit of effort in
1963 was not equivalent to one unit of effort in 1987, and that either the fishermen today
are more efficient, or that shrimp are more abundant The management implications of this
dichotomy are important. Research managers must know whether the apparent increase in
skill or efficiency is real (due to improved technology, better fleets, longer fishing days,
etc.) or reflects an actual increase in abundance of shrimp in water adjacent to the basin.
The increase in shrimp catch is not unique to the Pearl River basin. It has been reported for
all commercially caught estuarine-dependent species across the state. Recently Zimmerman
and others (NMFS, Galveston, Tex., unpublished data) have shown that the increase in
shrimp catch is related to increased recruitment of juveniles. They suggest that the marsh
edge habitat preferred by shrimp is increasing across the state as the marshes submerge and
break up. Clearly, more study is warranted before an informed decision can be made.
Indicator and Threatened/Endangered Species
Raptors and large mammals with extremely wide ranges integrate over space—their
presence is a sign of large natural areas with healthy food webs (Gosselink and Lee 1987).
The limited qualitative data available on raptors indicate that populations are at least stable in
the basin. Several indicator species—Florida panther, black bear, Southern Bald Eagle, and
Peregrine Falcon-are listed as regionally endangered or threatened. The presence of these
species reflects the ability of the basin to support far-ranging species. Managing for these
larger species includes consideration of the habitat requirements of smaller species and
should lead to conservation of balanced indigenous populations.
There are 15 species in the basin that are considered threatened. The map of species
occurrence (Figure 5-9) indicates that much of the habitat along and adjacent to the Pearl
River is considered critical under the Endangered Species Act This is valuable information
in creating management plans to restore these species to unlisted classification through
reclamation of habitat, and in conserving the basin's natural resources in general.
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REFERENCES
Anderson, S. H., and C. S. Robbins. 1981. Habitat size and bird community
management. Pages 511-520 in 46th Transactions North American Wildlife and
Natural Resource Conference.
Bond, R. R. 1957. Ecological distribution of breeding birds in the upland forests of
southern Wisconsin. Ecological Monographs 27:351-84.
Burdick, D. M., D. Cushman, R. B. Hamilton, and J. G. Gosselink. 1989. Faunal
changes and bottomla ! hardwood forest loss in the Tensas watershed, Louisiana.
Appendix 4 in Gosselink et al., Cumulative impact assessment and management in
a forested wetland watershed in the Mississippi River floodplain. LSU-CEI-89-02.
Marine Sciences Department and Coastal Ecology Institute, Louisiana State
University, Baton Rouge.
Butcher, G. S., W. A. Niering, W. J. Berry, and R. H. Goodwin. 1981. Equilibrium
biogeography and the size of nature preserves: an avian case study. Ecologia
49:29-37.
Council on Environmental Quality. 1978. National Environmental Policy Act,
implementation of procedural provisions: final regulations. Pages 55978-56005 in
Federal Register 43.
Council on Environmental Quality. 1984. 15th Annual report of the Council on
Environmental Quality. Washington, D.C. 719 pp.
Diamond, J. M. 1975. The island dilemma: lessons of modern biogeographic studies for
the design of nature reserves. Biological Conservation 36:129-146.
Galli, A. E., C. F. Leek, and R. T. T. Foreman. 1976. Avian distribution patterns in
forest islands of different sizes in central New Jersey. AUK 93:356-364.
Gosselink, J. G., and L. C. Lee. 1987. Cumulative impact assessment in bottomland
hardwood-forests. LSU-CEI-86-09. Center for Wetland Resources, Louisiana
State University, Baton Rouge.
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Harris, L.D. 1984. 1 he fragmented forest: island biogeography theory and the
preservation of biotic diversity. University of Chicago Press. Chicago, Illinois.
Kendeigh, S.C. 1944. Measurement of bird populations. Ecological monographs 14:67-
106.
National Research Council. 1986. Ecological knowledge and environmental problem
policy: concepts and case studies. National Academy Press. Washington, D.C.
388 pp.
Powers, J. E., and L. C. Lee. In press. Statistical criteria for assessing cumulative
impacts to wildlife populations in wetland ecosystems. Environmental
Management.
U.S. Army Corps of Engineers. 1970. Pearl River comprehensive basin study. Vol. 7.
U.S. Department of the Interior, Federal Water Quality Administration, Atlanta,
Ga.
U.S. Fish and Wildlife Service. 1978. Endangered and threatened species. U.S.
Department of the Interior. Region 4, Atlanta, Ga.
U.S. Fish and Wildlife Service. 1981. A resource inventory of the Pearl River basin,
Mississippi and Louisiana. U.S. Department of the Interior, Fish and Wildlife
Service, Ecological Services, Decatur, Ala.
Walker, D. A., P. J. Webber, M. D. Walker, N. D. Lederer, R. H. Meehan, and E. A.
Nordstrand. 1986. The use of geobotanical maps and automated mapping
techniques to examine cumulative impacts in the Prudhoe Bay Oilfield, Alaska.
Environmental Conservation 13(2): 149-160.
Weller, M. U., and C. E. Spatcher. 1965. Role of habitat in the distribution and
abundance of marsh birds. Special Report 43. Iowa State University of Science
and Technology, Department of Zoology and Entomology.
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Whitcomb, R. F., C. S. Robbins. J. F. Lynch, B. L. Whitcomb, M. K. Klimkewicz, and
D. Bystrak. 1981. Effects of forest fragmentation on avifauna of the eastern
deciduous forest. Pages 125-205 in Forest island dynamics in man-dominated
landscapes. Springer, New York.
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CHAPTER 6: SUMMARY AND SYNTHESIS
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n
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INTRODUCTION
In this chapter we summarize results of the Pearl River basin cumulative impact
assessment and discuss their implications for management of the living resources of the
basin. First, we examine the internal consistency of the indices used in the study as a
check on their validity. Second, we summarize the previous five chapters. Third, we
discuss the basin as an integrated landscape unit, emphasizing the interaction of structure
and function and the spatial pattern of structure and process. Fourth, we consider the
offshore zone influenced by the Pearl River, the river's contributions to this zone, and the
reciprocal influence of the marine environment on the lower reaches of the river. Finally,
we discuss the ecological condition of the Pearl River basin and suggest some approaches
to its future management.
INDICES OF LANDSCAPE STRUCTURE AND FUNCTION
The validity of conclusions drawn about the structural and functional characteristics
of the Pearl River basin depends heavily on how well the indices used in the analysis
represent the basin system. Gosselink and Lee (1989) summarized reasons for selecting
the indices, and discussed their utility as gleaned from other studies.
Maps and associated data on land use or land cover classes and interpreted remotely
sensed imagery from planes and satellites (LANDSAT TM and MSS) are probably the most
commonly used indices of landscape structure. In this study we compared 1973 maps
prepared from high-altitude imagery with 1987 maps classified electronically from
LANDSAT-MSS satellite imagery. Differences between the two maps are small, and most
pixels are classified the same way in both years. The small differences between years are
consistent with our understanding of changes occurring in the basin during the past 15
years. More importandy, they are consistent with the results of the analyses of functional
processes in the basin, which, in general, give a picture of a stable system in which
changes have been minimal and gradual.
This picture of generally stable land use in the basin was confirmed by comparision
with historical land use data from the U.S. Forest Service and the U.S. Department of
Agriculture. These data show that agricultural area has changed little since 1935, and non-
wetland and wedand forest area little since the 1960s.
The size of the mapping unit of the LANDSAT imagery, 6.25 ha/cell (250 m x 250
m grid) was fine enough to detect the dominant features of the 2.5 million ha Pearl River
basin. Linear features less than 250 m wide might have been missed. This means that
narrow riparian forest strips along low-order streams might be incorrectly classified, but
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land use maps and analysis of land cover on 250-m-wide strips along the major tributaries
of the Pearl River (Chap. 2) show sufficient resolution for the broad picture required for
this assessment. The color plates in Figures 2-14 and 2-15 contain less detail than the
tabular analyses (e.g., forest patch size and distribution). The latter arc based on 6.25-ha
cells. Four of these cells were aggregated for purposes of display in the report.
We used relatively few classes of land cover for this analysis. For example, we did
not distinguish between cultivated fields and pasture. This was partly because farmers
often rotate between these two uses, so dividing them is meaningless in analysis of long-
term data. The simplicity of the land cover classification also reflects the limitations of
electronic image processing. We could not readily distinguish between different types of
mixed deciduous forest, for example, by age or by time since the most recent logging. We
did, however, map coniferous forest. These relatively pure pine stands are probably all
plantations, maintained in a fairly short rotation for timber and pulpwood. The simplicity
of our classification system limited the depth of analysis, but we think the classes reflect the
major groups, both in terms of land cover and in terms of ecological processes.
Offshore the analysis of marsh change was obtained from a U.S. Fish and Wildlife
Service data set for the entire Louisiana coast. It has been extensively field verified
(Wicker 1980), and trends shown in the data set have been independently confirmed in
other studies.
Hydrologic data for the basin provide perhaps the most complete data set on a
functional attribute. Several discharge data sets span 50 years. This type of record has
been extensively used by the U.S. Geological Survey and the U.S. Army Corps of
Engineers (USACE), and its reliability and utility have been extensively verified Spatial
coverage is fairly comprehensive; stations range from the northern extremes of the basin to
the Bogue Chitto tributary in the south. Unfortunately there are no long-term records
below Bogalusa on the Pearl River, so data for the large wetland system of the lower river
near Slidell are lacking. The individual records are remarkably similar. Trends over the
period of record are slight. Perhaps the best indicators of the internal consistency of the
records are the rating curves, which have remained unchanged over the period of record.
Compared with hydrologic records, long-term water quality records for the basin
are seriously deficient. Only five stations having adequate records for analysis were
available; thus the coverage of the basin is incomplete, especially of the lower Pearl River
below Bogalusa. We could not, therefore, document any influence of the extensive lower
Pearl River wetlands on water quality. Water quality records showing any local influence
of the Jackson and Slidell metropolitan areas were also unavailable. The data records were
also fairly short-nutrient data are for the period since 1969. Only turbidity records are
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longer. Despite these inadequacies, the internal consistency of the data are adequate. For
example, total phosphorus (TP) was consistently correlated with turbidity across all
stations, turbidity was positively related to flow at three stations, and TP was positively
related to flow at the same three stations plus one other. Thus TP and turbidity are closely
correlated in their behavior, and this relationship is consistent throughout the data set. This
consistency was expected from earlier studies in other areas (Childers and Gosselink 1990;
Smith et al. 1982; Wetzel 1975). Since land cover has changed little over the last 60 years,
the absolute nutrient concentrations were more valuable in interpreting environmental
quality than were the temporal trends. This fact made the lack of long records less
important than might have been the case.
As Gosselink et al. (1990) previously found in a similar assessment, long-term
biotic data were generally scarce and related to birds. The six stations analyzed varied
widely in length of record (most had interrupted coverage, with a total of about 10 years of
surveys), but coverage was from all major parts of the basin. Even with the spotty records
and rather small recorded changes, analysis of changes in species composition correlated
rather well with changes in habitat along the survey routes. Data on current distribution of
species, especially threatened and endangered species, provided valuable additional
information about the current status of biota in the basin. For the inshore aquatic portions
of the study area, no long-term data were available. In the estuarine portion, shrimp and
fragmentary crab and finfish records exist, but are of questionable reliability. Each of these
data sets has serious drawbacks. For example, the breeding bird surveys are restricted to
roads and therefore probably underestimate interior forest species, and the source of shrimp
in the catch statistics cannot be reliability known. We backed up analyses of these records
with anecdotal information from individuals in Mississippi, Louisiana, and federal
environmental agencies, who collectively had many years of field experience throughout
the basin.
In summary, although serious gaps in the records limited the detail of the analysis
of the Pearl River basin ecosystem, the available records are adequate to provide a useful
and generally consistent picture of the basin's ecology.
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SUMMARY OF LAND USE, HYDROLOGY, WATER QUALITY,
AND BIOTA
Land Cover
Land use in the Pearl River basin has been fairly stable since the 1930s—about two-
thirds of the land is forest, and one third is in agricultural production. The basin has one
major metropolitan area, Jackson, Mississippi, and is on the edge of a second, Slidell,
Louisiana. During the past 15 years agricultural land has decreased slightly and been
replaced by forest (Figure 2-5). Pine plantations have expanded at the expense of plowed
fields and native mixed deciduous forests. Most of the deciduous and mixed deciduous
forest patches are small (<100 ha) (Figures 2-20, 2-21). When grouped, they form large
continuous forest areas, two of them greater than 240,000 ha (Figure 2-23). The pine
plantations tend to be extensive. Many are 1,000 ha or more, and the largest are about
15,000 ha. These pine plantations are concentrated in the northern part and in the lower
basin. Few are found in the large midsection. A major feature of the basin is the extent of
bottomland hardwood (BLH) and swamp forest along the Pearl River and its tributaries.
This is clearly shown in Figure 2-16, in which all the major streams are clearly delineated
because their floodplains are forested by swamps and bottomland hardwood trees.
Basinwide, forest borders 65% of the length of streams on both sides. The 44,000-ha
BLH/swamp forest of the lower basin is one of the largest relatively undisturbed wetland
tracts in the southeast and ranks with the Mobile River and Appalachicola River basins in
the east and the extensive Barataria/Atchafalaya basin in the west. These swamp and BLH
forest patches are major habitats for a number of threatened and endangered species.
Changes in land cover reflect a population shift from rural areas to cities and major
growth in and around Jackson. In addition, the Slidell metropolitan area just west of the
lower Pearl River basin is growing rapidly. This growth pattern has two diametrically
opposite effects. First, population growth in these two areas locally increases
environmental stresses from air and water emissions, direct habitat conversion, and
recreational use of forests and streams. This is primarily a local problem. On the other
hand, the population concentration in metropolitan areas has resulted in a reduction in the
rural population and a shift from agriculture to forestry. Ecologically, this pattern probably
is at least partly responsible for the fact that the qualities of water and habitat have remained
fairly good, as demonstrated by indices discussed in this report. The industrial growth of
the basin since the 1960s depends heavily on timber and agriculture (clothing, lumber,
wood, furniture, pplp and papers, and food processing). Therefore, it is in the interest of
the urban population as well as the rural to maintain the present flow of goods and services
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from the land-including timber, agricultural crops, good water quality, ecosystems that
minimize flooding, and a healthy biota.
Hydrology
Snagging and clearing the Pearl River for navigation during the late 1800s (Figure
3-11) probably significantly decreased the length of the streambed (removed meanders) and
the frequency of overflow onto the adjacent floodplain. However, no stage and discharge
records exist for that period. The only major hydrologic projects on the Pearl River in this
century have been for navigation in the lower Pearl, construction of the Ross Bamett
Reservoir north of Jackson, and small U.S. Soil Conservation Service (SCS) projects to
improve drainage in some tributaries (Table 3-1).
Stage and discharge of streams within the basin are controlled primarily by
precipitation. Although there are statistically significant trends in mean, variance about the
mean, minimum and maximum stage and discharge, the magnitudes of trends are small,
and no consistent pattern emerges. The single exception to these generalizations is mean
stage, which appears to have decreased in the upper pan of the basin. However, this
decrease is not reflected in the rating curves (stage vs. discharge), which appear remarkably
stable over the past 40-50 years. In general, the river is "well-behaved" and most, if not
all, of the fluctuations seen in both stage and discharge can be explained by natural climatic
variability.
In 1953 a navigation channel 37.6 km long with three locks parallel to the Pearl
River natural channel was completed-the last portion of a project to dredge the Pearl and
West Pearl rivers to provide navigation as far north as Bogalusa. This canal system has
been inoperative for many years, but in 1989 the USACE was authorized to reopen
navigation from the Gulf of Mexico as far as Bogalusa. There is also a navigation channel
on the East Pearl River to allow access by barge traffic to the Stennis Space Center, north
of Picayune. The effects of these projects on the relative flows between the East and West
Pearl rivers, saltwater intrusion into the river, and ecological changes to the large floodplain
forest of the lower Pearl River are now hotly contested issues.
Flooding is a local issue, associated with urban growth in the Jackson area. The
Ross Barnett Reservoir, north of Jackson, was built for a water supply and for recreation
and is ineffective for flood control. Since neither discharge nor the stage-to-discharge
relationship of the river has changed in the past 85 years, the increased flood damage is
probably due to human encroachment into the floodplain.
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Water Quality
In general stream water in the Pearl River basin is of sufficiently high quality to meet
standards recommended by EPA to prevent eutrophication (TP is < 0.1 mg 1_1; U.S.
Environmental Protection Agency 1976). Mean TP, over all stations and periods of record,
was about 0.09 mg 1"*. Mean nitrogen, as total Kjeldahl nitrogen (TKN), was 0.65 mg 1"*.
At no stations did TP exceed 0.1 mg 1" * more than one-third of the time (Table 4-3). Since
1969 TP concentrations have been stable or declined slightly. At the same time nitrogen has
been stable or increased. As a result N-to-P ratios have increased. An explanation of this
phenomenon is not clear.
TP was positively correlated with turbidity at all stations. Over the basin as a
whole, both turbidity and TP were positively related to discharge, though the slope of the
relationship was shallow, and discharge explained only a small fraction (about 8%-19%) of
the variability in the dependent variable. A positive slope is evidence of disturbance, but
the weakness of the relationship is evidence that the ecosystem is relatively undisturbed
(Smith et al. 1982).
Biota
Although overall the bird data are not sufficient to use bird species richness as a
blanket indicator of faunal species richness within the basin, the data do suggest that the
basin is relatively stable, at least in terms of bird species richness. Species abundance
either increased or remained relatively stable in five of the sue sites surveyed.
Correspondingly, land use also remained relatively stable. For example, forest land cover
decreased in only two of the six sites, and then by only approximately 10%, while forested
wetland remained stable at all but one site. At each site some species appear to be
declining, others to be increasing (Table 5-2). In most cases changes in abundance are
associated with changes in the corresponding preferred habitat along the survey routes-
figures 5-2, 5-3, 5-4).
Raptors, as wide-ranging top carnivores, are generally good indicator species for
large areas of habitat with healthy food webs. Raptor surveys by the Mississippi
Department of Wildlife Conservation (Table 5-5) indicate that populations for which there
are sufficient data are stable. Bald eagles are increasing, and no raptor species are known
to be decreasing.
Fisheries data from the offshore portion of the study area were extremely limited.
Therefore conclusions from them should be used with circumspection. Shrimp catch per
unit effort (CPUE) appears to have increased since about 1965, suggesting that either
shrimpers are more efficient, or that shrimp are more abundant. At the same time the
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annual variability in CPUE has increased dramatically. The increase in CPUE is similar to
that found coastwide and has been associated with increasing habitat (marsh/water edge) as
a result of marsh submergence (Zimmerman, NMFS, Galveston, Tex., pers.comm.).
Although the Pearl River basin coastal marshes are among the least disturbed on die
Louisiana coast, they still had a 15% loss between 1956 and 1978.
A number of animals found in the basin are listed as threatened or endangered
(Table 5-6; Figure 5-9). The major reason for population decline in nongame species is
habitat loss. That so many regionally listed species are found in the basin is probably a
reflection of the extent of relatively undisturbed habitat A map of their occurrence in the
basin (Figure 5-8) reveals that much of the habitat along and adjacent to the Pearl River is
considered critical under the Endangered Species Act
PEARL RIVER BASIN AS AN INTEGRATED LANDSCAPE
Interaction of Structure and Process
Structure, that is, land cover or land use and its pattern in the landscape, is closely
related to the ecological processes in a landscape (Forman and Godron 1986). Hydrology,
water quality, and biota all reflect the land use pattern of the landscape and the degree of
disturbance of that pattern. As documented for the highly disturbed Tensas Basin
(northeastern Louisiana), when a landscape is disturbed by forest clearing or by large-scale
flood control or navigation projects, indices of ecological function respond. Forest clearing
reduces infiltration by rain and increases runoff. Stream discharge and stage increase and
hydrographs are less stable; that is, flood peaks are higher and minimum discharge is
smaller (Belt 1975). Hood control or navigation projects change stream rating curves,
usually to lower peak stage:discharge, by deepening and straightening channels.
Watershed disturbance, especially forest clearing, also generally increases erosion, which
leads to increased stream turbidity and elevated nutrient concentrations. Alternative land
uses, such as agriculture, increase the loading rate of fertilizers and toxins, further
increasing stream nutrient concentrations. Forest loss and fragmentation lead to decreases
in the number of forest species and increases in the number of generalist and edge species.
Exotic species often invade the disturbed areas.
The four major indices by which we assessed the ecological condition of the Pearl
River basin paint a generally consistent picture. About two-thirds of the basin area is
forested, and the percentage has remained virtually unchanged since the 1930s. Most of
the rest of the basin is in agricultural production. Stability of land use is reflected in
stability of hydrographs and rating curves. These have changed little, if at all, over the
period of record. Stream hydrology is driven primarily by rainfall, infiltration, and
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evapotranspiration on the watershed. Water quality, as characterized by TP, is generally
within standards suggested by EPA (U.S. Environmental Protection Agency 1976), that is,
less than 0.1 mg 1"*. This is a reflection of the predominance of watershed forest cover
and forest-buffered streams (Omernik 1977). Turbidity and TP were shown to be
independent of, or to increase wily slighdy with, streamflow-further evidence that the
watersheds are not seriously disturbed (Hirsch et al. 1982). Finally, bird surveys revealed
only small changes in composition over the periods of record at different sites, and these
changes were generally related to small local land use changes along the survey transects.
Spatial Pattern of Structure and Process
Structure and process in a landscape are closely related to geography and
physiography. The comparison of a drainage basin to ?. funnel is appropriate for the Pearl
River basin. The watershed and small tributaries are like the sides of the funnel; they
receive rainwater, collect it, and pass it on to the larger tributaries until it passes through the
constricted end of the funnel represented by the lower river and flows out into the adjacent
estuaries. The structure, that is the land cover, of the funnel determines the dynamic
characteristics of hydrology, water quality, and biota. If rain falls on permeable surfaces
such as forested land, infiltration is maximized and surface runoff minimized. The
infiltrating water moves slowly downslope as interflow, delaying and reducing peak floods
and recharging aquifers. As runoff increases with a linear increase in land disturbance,
surface erosion and turbidity often increase exponentially (Murphree et aL 1976; Ursic
1965). Thus, as agricultural land replaces forest, peak discharge and stage increase in
receiving streams, and they become flashier. Because interflow decreases, minimum
stages also decrease. In the larger streams—the conduits of the system—flow is modified by
the surface characteristics of the floodplain. Streams such as these overflow their banks an
average of about once every year and a half (Leopold et al. 1964). The size and plant cover
of the overflow area determine the peak stage and the steepness of the flood hydrograph.
Most of the basin is characterized by forested, rolling hills and relatively coarse
sedimentary deposits (USACE 1970). These conditions favor infiltration of rain, slow
downslope interflow, and retard discharge into stream beds. Furthermore, the forested
floodplain along the major streams, especially the lower Pearl River, slows their discharge
rates during floods. The net effect on streamflow is to minimize flood peaks and maintain
flows throughout the year. There is a slight tendency for the watersheds of the upper river
(the Upper Pearl, Yockanookany, Tuscalameta, and Pelahatchie) to be the most heavily
forested, and therefore probably the most effective in minimizing and retarding runoff, but
this difference between subbasins is minor. Even the least forested Bogue Chitto River
168

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watershed has more than 50% cover, and 70% of the river's border is forested (Figures
6-1, 6-2).
Returning to the analogy of the funnel, three attributes control the water quality of
streams in the Pearl River basin: (1) In the collecting watershed, the relatively undisturbed
natural cover improves infiltration and minimizes erosion. Forest covers over two-thirds of
the watershed surface of the upper basin. Only the two lower sub-basins, the Bogue Chitto
and Lower Pearl, and Richland Creek (which contains the large Jackson urban area) have
less than two-thirds forest cover. (2) Between the watershed and the collecting stream,
forest cover of the riparian zone acts as a filter, catching sediments and nutrients washed
from the watershed (Peteijohn and Corell 1984). Except for the Bogue Chitto and
Richland Creek sub-basins, at least 85% of the borders of major streams are forested. (3)
In the major conduits of the watershed, especially the lower delivery system of the funnel,
width of the floodplain, meanders of the river, and forest cover retard flow and filter and
transform nutrients (Elder 1985). The Pearl River, at its lower end, meanders through a
broad 44,000-ha forested wetland. Below this the river traverses an expanse of herbaceous
marsh before it flows out into the coastal estuary. Although no data are available to allow
analysis of the influence of this wetland on water quality, many other studies (see summary
in Mitsch and Gosselink 1986) indicate that it is probably a net sink for sediments, and a
source of organic nutrients.
For animals the river floodplain is a ready source of water. It supports a diverse
flora because of its complex elevational and moisture gradients, and contains the faunal
richness of an ecotone that includes aquatic, wetland, and upland habitats. As a result, the
bottomland and swamp forest river corridors support a dense flora and fauna, and include
critical habitats for threatened and endangered species (Figure 5-9). Some of these species
are aquatic, living in unpolluted reaches of the stream. Such animals as the Florida
panther, which used to occur in the basin, require extensive (>100,000 ha) tracts of
unbroken forest cover. For still others, such as the bald eagle, the size of the natural area
and the interspersion of different cover types is probably significant Portions of the river
conidor have protected status as parks and wildlife refuges, including about 32,000 ha on
the Bogue Chitto and lower Pearl River (Figure 1-8). Elsewhere in the basin protected
areas span most of the major habitat types, from piney woods to mixed deciduous forests
to offshore marshes and barrier islands. These protected areas form a nucleus for natural
resource planning in the basin.
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Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Yockanookany
Upper Pearl
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Yockanookany
Upper Pearl
20	30
% Agriculture
o
C.
Lower Pearl
Bogue Chitlo
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Yockanookany
Upper Pearl
100
d.
Lower Pearl
Bogue Chitto
Middle Pearl
Strong River
Richland Creek
Pelahatchie
Tuscalameta
Yockanookany
Upper Peart
% Natural Stream Corridor*
% Developed Stream Corridor
Figure 6-1. Percentage of land cover in Pearl River sub-basins.
~Natural = forest or marsh

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Yockanookany
Sub-Basin
Richland
Sub-Basin
Bogue Chitto
Sub-Basin
Pelahatchie
Sub-Basin
Upper Pearl
Sub-Basin
TtNH
iff MISS.




4




Lower Pearl
River
~ Agriculture/Forest
Bottomland Hardwood/Wetland Forest
Forest
Forest/Agriculture
Urban
Rivers
Sub unit boundaries
0	10 20 30 40 Kilomet«rg
	1	I	I	I	I
N
Figure 6-2. Functional subunits of the Pearl River basin.
ni

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ONSHORE-OFFSHORE INTERACTIONS
The Influence of the River on the Estuary
The West Pearl River, which carries most of the flow to the coastal estuary, empties
into the Rigolets, the tidal pass between Lake Pontchartrain and Lake Borgne. On rising
tides the river's flow is carried into Lake Pontchartrain, where it mixes with the brackish
water of the lake before flowing Gulfward through the Rigolets and Chef Menteur pass on
ebbing tides. On falling tides the flow of the Rigolets carries Pearl River water directly into
Lake Borgne and thence into Mississippi Sound. Freshwater flow from the Pearl River
averages about 300 cms; the maximum during late winter is about 550 cms, and the
minimum during late summer about 150 cms (see Chap. 3). The average flow is about
11% of the total tidal prism and may be as much as 20% during flood conditions. (Fresh
water from smaller rivers entering Lake Pontchartrain also freshens the estuary. Their total
freshwater discharge is less than one-half of the Pearl River flow.) Isohalines based on
1968 data from the Lousiana Department of Wildlife and Fisheries delineate the river's
sphere of influence within the adjacent estuaries (Barrett 1971). Figure 6-3 shows that
during high river flow (January) the 10-ppt isohaline is pushed out to the southeastern edge
of the coastal marshes. During low flow periods (August), the same isohaline has retreated
to enclose a small area in Lake Borgne around the Rigolets and Chef Menteur Pass (Figure
6-4). Salinities in marshes southeast of Lake Borgne are still well below Gulf salinities,
indicating some freshwater influence. Thus, the area influenced by the Pearl River varies
with season, probably extending out as far as the Chandeleur Islands during winter.
Estimates of nutrient fluxes from the Pearl River were presented in Chapter 4.
Since we used water quality data from near Bogalusa, the flux estimates ignore any effects
of the swamps and marshes of the lower river. If Elder's (1985) study of the Apalachicola
River can be generalized to the Pearl River basin, this extensive wetland area in the mouth
of the river may not significantly affect TP and TKN fluxes, but organic forms of these
nutrients may be increased at the expense of inorganic forms.
The total annual flux of phosphorus delivered to the estuary by the Pearl River was
estimated to be from 500 to > 2,000 MT (Table 6-1). Since the TP concentration varied
little with discharge, year-to-year variations were mosdy due to changes in rainfall and
hence discharge. In terms of a unit of offshore area (i.e., Lake Borgne), as defined for this
study, that is equivalent to 3.6 kg-ha'* (0.36 gm"2). Diluted in the volume of Lake
Borgne the load is about 1 mg l"l-yr*l. To give some perspective, a marsh producing
2,000 g m"2 organic material incorporates about 2 g of phosphorus. Therefore, on average
172

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Figure 6-3. Isohaline contours, high river flow, Januaiy 1968 (from Bairett 1971).

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Figure 6-4. Isohaline contours, low river flow, August 1968 (from Barrett 1971).

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Table 6-1. Estimated fluxes from the Pearl River to the adjacent estuary.
Units	Mean Maximum Minimum
Hydrology
Discharge of Pearl River	m^-s"!	300	550	150
Flow of Pearl River over	m^	2.7x10^ 4.95x10^	1.35x10^
25-h cycle
Replacement time for L. Borgne3	days	45 25	90
Salinity: marshes SE of L. Borgne	ppt	20	10
Phosphorus
TP discharge from Pearl R.	MT-yr"l	1,500 2,360	530
TP load to estuary, per unit offshore kg-ha'^-yr"^ 3.6	5.7	1.3
areab
TP load to estuary, per unit volume mgl" 1 yr" 1	1.0
of L. Borgne
Nitrogen
TKN discharge from Pearl R.	MT-yr'1 11,510 29,960 2,800
TKN load to estuary, per unit	kg-ha"l-yr~l 28	72	6.7
offshore area
TKN load to estuary, per unit	mg l" 1 yr * 8.3
Carbon
Carbon load to off shore zone, per	kg- ha" 1 • yr" * 420
unit offshore areac
al.l9 x 10® m3 volume (Barrett 1970).
b414,000 ha.
cAssuming C:N ratio of 14 (Hecky and Kilham 1988).
175

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the river may contribute about 15% of the phosphonis needed for organic production. In
most marshes the primary nutrient source is recycled organic matter (Mitsch and Gosselink
1986). Riverine sources are probably the major "new" nutrients, and in Lake Borgne the
Pearl River is the primary source (except during years when the Bonnet Carrf spillway is
opened). Examination of seasonal TP concentrations in Lake Borgne and adjacent marshes
(Barrett 1971) reveals that TP is inversely related to river flow. That is, TP concentrations
are highest in late summer when river flow is lowest These concentrations probably
reflect the net effect of local nutrient recycling, especially mineralization, which is
positively correlated with temperature.
Nitrogc: s more likely to limit primary production in estuaries than phosphorus.
The total annual nitrogen load from the Pearl River to the offshore zone was estimated at
2,800-30,000 MT, or about 28 kgha*l*yrl on a unit area basis (Table 6-1). In terms of
the volume of Lake Borgne, the load is about 8 mg-l'lyr*. Again, this is about 15% of
the nitrogen needed for primary production. No data are available on total N
concentrations in Lake Borgne, but Lake Borgne nitrate concentrations are positively
correlated with Pearl River flow. This provides some weak evidence that the flux of
nitrogen from the Pearl River may be a significant factor in offshore primary production.
Although, in comparison to the Mississippi River in the west and the
Mobile/Tombigbee rivers in the east, discharge of the Pearl River is small, it noticeably
influences salinity in Lake Borgne and Mississippi Sound, and probably is the most
important nutrient source for the local coastal marshes. These marshes in turn support
excellent harvests of shellfish and fish.
Influence of the Estuary on the Pearl River Basin
The reciprocal influence of the estuary on ecological processes in the Pearl River
basin is probably not as strong as the outflux from the river to the estuary. However,
estuarine waters are known to influence the lower river in two ways: salinity intrusion and
fish migration.
Salt water intrudes up the river a maximum distance of 25 km, depending on river
stage (Figure 3-9). This intrusion is primarily in the East Pearl River, which receives little
freshwater flow. The plant communities of the lower Pearl River swamp and marsh reflect
saltwater intrusion, particularly the salt-tolerant marshes at the lower end and the scrub
forest north of them, which receive periodic pulses of saline water (White 1983). There is
anecdotal evidence of suppression of plant production because of periodic saltwater
intrustion but no supporting data.
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The lower marshes serve as a nursery for estuarine-dependent fisheries and shell-
fisheries. One anadromous species, the Atlantic sturgeon, has been reported 100 km or
more up the lower Pearl and the Bogue Chitto rivers (Figure 5-9). This species is on the
federal endangered species list
DEVELOPMENT OF GOALS AND PLANS
This report's ecological characterization of the Pearl River basin was designed to
provide the technical information needed to manage the basin as a unified landscape
system. In Chapters 1-5 we analyzed available sociological and ecological information. In
this chapter we summarized the results of this analysis and combined them into an overall
evaluation of the ecological status of the basin. We called attention to strengths in the basin
ecosystem and pointed out potential problem areas such as the Jackson urban area.
Management implies the establishment of goals for the basin, based on its present
ecological condition, and plans for implementation of those goals. Goal setting is properly
a function of the federal, state, and local governing authorities with responsibilities within
the basin; local businesses and environmental interests; and individuals who live in the
basin (Gosselink and Lee 1989). We cannot, in this report, anticipate their goals, and in
the absence of goals, we cannot recommend implementation strategies. However, in the
following section we broadly outline a possible scenario to illustrate the process of goal
setting and planning. We emphasize that there is no single correct goal (or set of goals) for
management of the basin because goals reflect the values of those who manage the
resource, as constrained by their understanding of the "health" of the system. For
example, most of the basin is forested (64%). It is probably unrealistic to set a goal of
100% forest cover for the basin, but different planning groups might set goals of 75%,
65%, or 35% forest cover, depending on the importance of forests in achieving their
management objectives.
We illustrate one set of reasonable goals and implementation strategies for achieving
those goals from a five-day workshop on cumulative impact assessment held October 17-
21,1988, in Slidell, Louisiana.1 Participants in the workshop represented a number of
federal and state environmental agencies, commercial interests, and environmental groups.
Four groups within the workshop developed goals and plans independently. The goals
were in reasonable agreement; implementation strategies differed somewhat, but the main
features agreed. Table 6-2 summarizes management goals for the Pearl River basin, and
Table 6-3, implementation strategies, as modified from this workshop. These are
Cumulative Impact Assessment in Southeastern Wetland Ecosystems: the Pearl River. October 17-21,
1988, Slidell, La. Sponsored by the U.S. Environmental Protection Agency, Washington, D.C.
177

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presented merely to provide the reader with one approach to goal setting and planning, and
the lists represent an example of a reasonable management approach to the basin.
Goals
Compared to other basin landscapes that have been studied, the Pearl River basin is
in reasonably good shape ecologically. Therefore the primary mission of the goal-setting
exercise was the ecological protection and enhancement of the Pearl River
basin. That is, we did not envision a major restoration process, but rather the protection
of the present renewable resources and their enhancement where feasible. Specific goals
listed in Table 6-2 relate to water quality, hydrology, biota, and human development, as
appropriate to achieve this overall protection. (1) Water quality. Stream water is of
generally high quality. Therefore the goal is to improve water quality to meet Clean Water
Act (CWA) standards for running waters where those standards are not met and maintain
the existing higher standards where they are. (2) Hydrology. Hydrology is a key factor in
the basin ecosystem. The historical inundation of the floodplain is partly responsible for
the high quality of water, forests, and biota. The goals are to restore this historic flooding
pattern of the floodplain and to eliminate stream bed degradation due to gravel mining. (3)
Biota. The goal has two aspects. First, maintainence and restoration of "balanced
indigenous populations" of flora and fauna is a goal consonant with the aims of the CWA,
which coined the term in quotation marks. The second aspect focuses on protection of
wide-ranging animals, the terrestrial bear and the aquatic anadromous fish. Protection of
these animals ensures the protection of large, diverse tracts of appropriate habitat, which in
turn ensures habitat availability for smaller animals and plants. (4) Finally, since the basin
economy is presently based primarily on renewable resources, it is imperative that future
economic growth ensure the ability of the basin to provide a continuous supply of these
resources. Therefore, this goal is to encourage diversification and development of
economic systems that can exist in harmony with the environment
Implementation Strategies
A major key to implementation of the above-stated goals is protection and
enhancement of the ecological structure of the basin, including not only the relative
proportions of different cover types, but also the pattern of those cover types. Thus the
most important strategies for implementing the goals deal with landscape structure (Table 6-
3). These strategies are multipurpose in the sense that they often help to implement more
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Table 6-2. An example of goals for ecological protection and enhancement of the Pearl River
basin.
WATER QUALITY
GOAL 1: Maintain and/or restore excellent water quality in all zones of the wetland continuum
A.	Meet minimum water quality standards at least
B.	Non-degradation where standards are already exceeded.
Rationale: Pearl River basin water quality generally is good. Ensure that Gean
Water Art goals are met
HYDROLOGY
GOAL 1: Maximize hydrologic interactions in all zones of the wetland continuum.
GOAL 2: Eliminate stream bed degradation.
Rationale: Pearl River basin has lost stream length, sinuosity, retentiveness.
Gravel mining, some channel training has occurred Goals are to
increase retention time, floodplain flooding for wetland, water
quality, and aquatic biota.
BIOTA
GOAL 1: Restore balanced indigenous floral and faunal populations in the Pearl River basin
where degraded, as indicated by such wide-ranging animals as the black bear and
anadramous fish.
Rationale: Pearl River basin supports threatened and endangered species; much
management for sport species. Goals focus on developing habitat for
balanced indigenous populations, using black bear and anadromous
fish as guild leaders.
OTHER
GOAL 1: Encourage economic enterprises that maximize responsible use of non-renewable
resources and non-consumptive uses.
Rationale: Aim is to encourage diversification and development of economic
systems that can exist in harmony with the environment
Source: Modified from goals suggested at the workshop "Cumulative Impact Assessment in Southeastern Wetland
Ecosystems: the Pearl River." October 17-21,1988, Slidell, Louisiana. Sponsored by the U.S. Environmental
Protection Agency, Wasiungton, D.C.
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Table 6-3. Possible strategies to implement Pearl River basin goals outlined in Table 6-2.
Strategy
Goal3
Rationale
Tools
JO
o
Structure (land cover)
1. Riparian buffers
a. In low-order streams continuous
buffer strips at least 50 m wide/side
in hardwood species; never clear-cut.
WQ
B
b. In Pearl River maintain bottomland	B
forest in the entire floodplain; manage H2O
to maintain cover, ecologically functional WQ
forest (e.g., best management practices,
mature stands, etc.).
2. Limit use of steep slopes	WQ
(> 10%) for forests. Overall	B
maintain > 65% forest cover.
3. Increase connectivity of large	B
forest patches by acquisition of	WQ
corridors, especially along streams.	H2O
Water Quality
1.	Stringent enforcement of water quality WQ
standards.
2.	Develop and enforce plans to minimize WQ
non-point pollution.
Hydrology
1. Open up dead arms and side channels. H2O
B
Act as filter strip for upland
runoff and as a corridor for
biota. Some floodwater storage.
Provide corridor for biota.
Increase interaction of water in floodplain.
Improve WQ.
Minimize runoff.
Provide large forest patches.
Increase patch size for guild leaders.
Improve filter strips.
CWA Sec. 404
Conservation Reserve Program
Filter strips, Food Security Act
Sec.404
Conservation Reserve Program
Swamp-buster
Agreements with Commercial
timber interests.
CRP-erodible land
Hunting leases, education
Acquisition (e.g., TNQ
CRP easements
Trusts
CWA Sees. 401,402
Increase retention time; Improve aquatic
habitat diversity.
CWA Sec. 319
USACE projects
(Continued)

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Table 6-3. (Continued.)
Strategy
Goal
Rationale
Tools
Hydrology (continued)
2.	Eliminate dikes, spoil banks in	H2O
floodplain.
3.	Revegetate stream banks.	H2O
4.	Condition gravel mining permit	H2O
requests to minimize point bar
depletion of coarse material.
5.	Feasibility study of underwater	B
sill near Pearl River mouth to
decrease salinities in lower river.
6.	Eliminate further development in	WQ
in urban floodplains. B
H2O
Biota
1.	Full implementation of Endangered Species B
Act to guarantee no jeopardy to resident
threatened and endangered species.
2.	No hunting of bears for 30 yr.	B
3.	Study Atlantic sturgeon to identify	B
conditions necessary for continued
survival in Pearl River.
Improve water overflow in floodplain.
Stabilize stream banks.
Minimize stream bed cutting and
restore stream stability.
Reduce saltwater intrusion for
improved stability of swamp
forest.
Minimize social damage from
floods; minimize floodplain degradation
and water pollution.
Part of strategy to improve habitat
for balanced indigenous populations.
Bring back bear populations.
Strategy to improve habitat for
anadromous fish.
USACE projects
USACE projects
Sec. 404
USACE
FEMA
ESA
Mississippi DNR
Source: Modified from goals suggested at the workshop "Cumulative Impact Assessment in Southeastern Wetland Ecosystems: the Pearl River." October 17-21, 1988,
Slidell, La. Sponsored by the U.S. Environmental Protection Agency, Washington, D.C.
aSee Goals, Table 6-2. WQ = water quality, B = biota, H2O = hydrology.

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than one functional (water quality, hydrologic, and biotic) objective. The goals addressed
are shown in column two of Table 6-3. The table also suggests social mechanisms (tools)
to facilitate implementation (last column).
A glance at Figure 5-9 illustrates the importance of the riparian zone for threatened
and endangered species. The integrity of the zone is illustrated in Figure 2-15, which
clearly shows the forested bottomlands, nearly continuous along all the major basin
streams. Structural goals la, lb, and 3 are intended to protect and enhance forested
riparian strips along low-order streams and the entire floodplain along higher-order
streams. These strips will buffer the streams from excess nutrient and sediment runoff,
serve as short-term reservoirs during floods, and improve habitat, especially corridor
access to the stream from upland, and between isolated forest patches. CWA Sec. 404 and
the swamp-buster provisions of the Food Security Act of 1985 provide regulatory
mechanisms to discourage farming in the riparian zone, while the Conservation Reserve
Program (also in the Food Security Act) can be used to "rent" wildlife easement from the
owner of the land. As with all the structural strategies, acquisition of key land tracts is
another, albeit expensive, alternative.
To minimize runoff and erosion, and to provide forest cover for biota, especially
interior forest species, overall forest cover should be maintained at about two-thirds of the
basin area, and slopes greater than 10% should not be cleared. The two-thirds forest cover
target is the present forest cover and is also well above the minimum cover necessary for
good water quality (Omemik 1977). Steep slopes are particularly prone to erosion and
difficult to replant. Therefore they require special consideration. Regulatory mechanisms
to implement this goal are few. Therefore the strategy should be the use of incentives such
as the Conservation Reserve Program for highly erodible lands (Food Security Act),
agreements with large commercial timber companies, and education of the population on
the importance of these measures.
Additional measures can be implemented to deal with more specific problems and to
supplement these structural goals. (1) Water quality. Existing regulations are sufficient to
ensure compliance with the CWA, but strict enforcement is required, in particular strict
control of point sources of discharge through NPDES permits and the mandated
development of plans to control non-point sources of pollution. (2) Hydrology. When the
Pearl River channel was snagged in the late 1800s, it was also shortened. Opening up dead
side channels and arms would improve retention time and aquatic habitat diversity.
Similarly elimination of spoil deposits in the floodplain would restore flooding to the
floodplain. Revegetation of stream banks where necessary would reduce erosion. All
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these goals could be implemented through US ACE projects. There are gravel mines on the
river. These change local river morphology, deplete coarse materials downstream, and
pollute the water. These mines operate ox Sec. 404 permits. As the permits come up for
renewal, they should be conditioned to lessen the environmental impact of the operation to
minimize stream bed cutting and downstream pollution. The questions of the division of
water between the East and West Pearl River in the lower reaches and of saltwater intrusion
could not be answered in this broad overview of the Pearl River basin. However, the
management decisions about these important local problems will have far-reaching
implications for the future of the lower Pearl River ecosystem. Therefore, one strategy is
to recommend a further, detailed feasibility study of these problems, to be funded by the
US ACE. Finally, an important goal is to use agreements with the Federal Emergency
Management Agency (FEMA) to eliminate further human development in the floodplain.
Since the stage-to-discharge relationship of the river appears to be unchanged at Jackson,
and since the relationship between precipitation and runoff has not changed, increased
damages from periodic local flooding at Jackson appear to be related to human occupancy
of the floodplain. These problems should be dealt with at the local level through FEMA.
(3) Biota. Specific strategies for the protection of biota include full implementation of the
Endangered Species Act to safeguard and enhance habitat for a balanced indigenous
population and a ban on hunting bears for 30 years to allow populations to rebuild to self-
sustaining levels. Finally, a recommended study of the Atlantic sturgeon would identify
conditions necessary for its continued survival in the Pearl River. This study should be
coordinated with the recommended study of the East and West Pearl so that the hydrologic
design of the lower river system will be compatible with the life requirements of the
sturgeon.
Dearly, these goals and implementation strategies are not sufficient to provide
management answers to the many local, site-specific problems that arise in a land area this
size. The purpose of a basin-level management plan is to set the large stage and overall
goals to provide a design framework for the long-term management of the basin. Since all
the basin interests have subscribed to it, community directions are clear, and much conflict
is avoided. When inevitable local conflicts occur and site-specific Sec. 404 permit requests
are evaluated, the context of the overall goals gives the regulator a clear vision of the future
and a mandate for responsible action.
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watershed: observations on the role of a riparian forest Ecology 65 (5): 1466-
1475.
Smith, R. A., R. M. Hirsch, and J. R. Slack. 1982. A study of trends in total
phosphorus measurements at NASQAN stations. Water Supply Paper 2190. U.S.
Geological Survey, Washington, D.C.
U.S. Army Corps of Engineers (USACE). 1970. Pearl River comprehensive basin study.
U.S. Army Corps of Engineers, Mobile District, Mobile, Ala.
U.S. Environmental Protection Agency. 1976. Quality criteria for water. U.S.
Environmental Protection Agency, Washington, D.C 256 pp.
Ursic, S. 1965. Sediment yields from small watersheds under various land uses and
forest owners. Proc. Federal Inter-agency Sedimentation Conference. U.S.
Department of Agriculture, Misc. Public. 970:41-52, Washington, D.C.
1S5

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Wetzel, R. G. 1975. Limnology. Saunders College Publishing Co., Philadelphia.
White, D. A. 1983. Plant communities of the lower Pearl River basin, Louisiana. American
Midland Naturalist 110 (2):381-396.
Wicker, K. M 1980. Mississippi deltaic plain region ecological characterization: a habitat
mapping study. FWS/OBS-79/07. U.S. Fish and Wildlife Service, Office of
Biological Services, Washington, D.C.
186

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APPENDIX A
Statistical Analysis of Stage and Discharge Records
187

-------
/¦)
"f

-------
This appendix presents results of the statistical analysis of stage and discharge records from the
Pearl River basin. The data come from the U.S. Geological Survey in the form of daily values.
These daily values were used to create the monthly and yearly means, variance about the mean,
minima, and maxima used in the analysis. The data set was divided into two periods, pre-1971
and 1971-1988, each of which was analyzed separately. In addition, a third series, in which data
from the large flood years of 1974,1979, and 1983 were deleted, was also created and analyzed.
This procedure was used to remove the strong precipitation influence on the data. The tables are
presented as follows:
Seasonally adjusted ANOVA on entire data set	Tables 1-4
Seasonally adjusted ANOVA on data prior to 1971	Tables 5-8
Seasonally adjusted ANOVA 1971-1988 data	Tables 9-12
Seasonally adjusted ANOVA without 1974,1979,1983
Regression of annual data on time for entire data set
Regression of annual data on time for data prior to 1971
Regression of annual data on time for 1971-1988 data
Tables 13-16
Tables 1-4
Tables 5-8
Tables 9-12
Regression of annual data on time without 1974, 1979, 1983 Tables 13-16
189

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Table A-1. Summary statistics from seasonally adjusted ANOVA on monthly mean discharge and
stage as a function of time, for USGS stations in the Pearl River Basin. Indicated
are; the station number, a description of the location, the slope (change per month),
the value, the T value and the probability. The R2 is for the entire seasonal
model, which includes sine and cosine terms to account for the annual signal.
Stations for which the model was not significant at the 95% level are indicated by the
symbol ns. The symbol nd indicates no data . The entire record was used for this
analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
0.0197
0.370
3.112
0.0019
02482550 '
Pearl River @ Carthage
0.1055
0.362
2.718
0.0069
02483000
TuscaJameta Creek @ Walnut Grove
0.0139

3.368
0.0008
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
0.0396
0.347
2.745
0.062
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
0.1210
0.389
2.804
0.0052
02488700
While Sand Creek @ Oak Vale
0.0091
0.269
2.823
0.0051
02489000
Pearl River @ Columbia
-0.177
0.383
-2.278
0.0234
02489500
Pearl River @ Bogalusa
0.228
0.405
3.92
0.0001
02490105
Bogue Lusa Creek @ Highway 439
0.007
0.241
3.22
0.0014
02490500
Bogue Chitto River @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
NS



Stage Data (meters)
Station
Location
Slope
R2
T
02481880
Pearl River @ Bumside
NS


02482000
Pearl River @ Edinburg
NS


02482550
Pearl River @ Carthage
-0.004
0.613
-3.749
02483000
Tuscalameta Creek @ Walnut Grove
NS


02484500
Yockanookany RiveT @ Ofahoma
-0.004
0.600
-5.018
02484630
Pearl River @ Ratcliff
!®


02585700
Hanging Moss Creek @ Jackson
NS


02486000
Pearl River @ Jackson
NS


02488000
Pearl River @ Rockport
NS


02488500
Pearl River @ Monticello
NS


02488700
White Sand Creek @ Oak Vale
NS


02489000
Pearl River @ Columbia
ND


02489500
Pearl River @ Bogalusa
ND


02490105
Bogue Lusa Creek @ Highway 439
ND

-5.15
02490500
Bogue Chitto River @ Tylertown
-0.002
0.466
02492000
Bogue Chitto River @ Bush
ND


Probability
0.0002
0.0001
0.0001
100

-------
Table A-2. Summary statistics from seasonally adjusted ANOVA on variance about the monthly
mean discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The entire record was
used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl RiveT @ Bumside
NS



02482000
Pearl River @ Edinburg
23.267
0.036
2.322
0.0205
02482550
Pearl River @ Carthage
NS



02483000
Tuscalameta Creek @ Walnut Grove
1.959
0.1076
2.600
0.0096
02484500
Yockanookany RiveT @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
15.172
0.068
2.567
0.0104
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
49.077
0.129
3.720
0.0002
02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
NS



02489500
Pearl River @ Bogalusa
70.684
0.136
4.012
0.0001
02490105
Bogue Lusa Creek @ Highway 439
NS



02490500
Bogue Chitto River @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
NS



Stage Data (meters)
Station
Location
S
02481880
Pearl River @ Bumside
NS
02482000
Pearl RiveT @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl RiveT @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl RiveT @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
ND
Slope
R2
Probability
191

-------
Table A-3. Summary statistics from seasonally adjusted ANOVA on monthly minimum discharge
and stage as a function of time, for USGS stations in the Pearl River Basin.
Indicated are; the station number, a description of the location, the slope (change per
month), the value, the T value and the probability. The R2 is for the entire
seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The entire record was
used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
0.004
0.402
2.133
0.0341
02482550
Pearl River @ Carthage
0.030
0.407
2.678
0.0078
02483000
TuscaJameta Creek @ Walnut Grove
0.001
0.459
2.935
0.0035
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl RiveT @ Momicello
NS



02488700
White Sand Creek @ Oak Vale
0.004
0.9755
9.208
0.0001
02489000
Pearl RiveT @ Columbia
-0.082
0.332
-2.106
0.0360
02489500
Pearl River @ Bogalusa
0.071
0.279
2.193
0.0287
02490105
Bogue Lusa Creek @ Highway 439
0.002
0.354
5.333
0.00001
02490500
Bogue Chitto River @ Tylertown
-0.001

-1.988
0.0473
02492000
Bogue Chitto River @ Bush
NS





Stage Data (meters)



Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.002
0.602
-2.958
0.0035
02483000
Tuscalameta Creek @ Walnut Grove
0.001
0.418
3.498
0.0035
02484500
Yockanookany River @ Ofahoma
-0.003
0.605
-6.975
0.0001
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
0.001
0.134
2.894
0.0049
02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
0.0002
0.161
2.863
0.0047
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.001
0.552
-9.669
0.0001
02492000 Bogue Chitto River @ Bush	ND
192

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Table A-4. Summary statistics from seasonally adjusted ANOVA on monthly maximum discharge
and stage as a function of time, for USGS stations in the Pearl River Basin.
Indicated are; the station number, a description of the location, the slope (change per
month), the value, the T value and the probability. The R2 is for the entire
seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The entire record was
used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
0.0888
0.202
3.254
0.0012
02482550
Pearl River @ Carthage
0.3692
0.195
2.449
0.0149
02483000
Tuscalameta Creek @ Walnut Grove
0.0768
0.233
3.065
0.0023
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
0.1268
0.269
3.614
0.0003
02488000
Pearl River @ Rock-port
NS



02488500
Pearl River @ Monticello
0.2995
0.361
0.0002
0.0002
02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
-0.3163
0.389
-2.465
0.0142
02489500
Pearl RiveT @ Bogalusa
0.4377
0.374
4.267
0.0001
02490105
Bogue Lusa Creek @ Highway 439
0.039
0.111
2.001
0.0465
02490500
Bogue Chitto RiveT @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
NS





Stage Data (meters)



Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS .



02482550
Pearl River @ Carthage
-0.005
0.508
-2.73
0.0069
02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
-0.006
0.498
-3.474
0.0006
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl RiveT @ Jackson
0.004
0.479
2.298
0.224
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
-0.002
0.225
-2.084
0.0387
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.004
0.300
-2.36
0.0194
02492000 Bogue Chitto River @ Bush	ND
193

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Table A-5. Summary statistics from seasonally adjusted ANOVA on monthly mean discharge and
stage as a function of time, for USGS stations in the Pearl River Basin. Indicated
are; the station number, a description of the location, the slope (change per month),
the value, the T value and the probability. The R2 is for the entire seasonal
model, which includes sine and cosine terms to account for the annual signal.
Stations for which the model was not significant at the 95% level arc indicated by the
symbol ns. The symbol nd indicates no data. Data prior to 1971 was used for this
analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl RiveT @ Bumside
ND



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carlhage
0.229
0.380
1.984
0.0498
02483000
Tuscalarnela Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
ND



02486000
Pearl RiveT @ Jackson
NS



02488000
Pearl River @ Rockport
0.757
0.469
2.963
0.0035
02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
NS



02489500
Pearl River @ Bogalusa
NS



02490105
Bogue Lusa Creek @ Highway 439
NS



02490500
Bogue Chitto River @ Tylertown
-0.032
0.261
-3.274
0.0012
02492000
Bogue Chitto RiveT @ Bush
-0.031
0.250
-2.038
0.0422
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	ND
02482000	Pearl River @ Edinburg	ND
02482550	Pearl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
02488700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	ND
02492000	Bogue Chitto River @ Bush	ND
194

-------
Table A-6. Summary statistics from seasonally adjusted ANOVA on variance about the monthly
mean discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data . Data prior to 1971
was used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
NS
02488000
Pearl River <§> Rockport
125.78
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
R2
Probability
0.1941
2.747
0.0067
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Burnside	ND
02482000	Pearl River @ Edinburg	ND
02482550	Pearl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
02488700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500 Bogue Chitto River @ Tylertown	ND
02492000 Bogue Chitto River @ Bush	ND
195

-------
Table A-7. Summary statistics from seasonally adjusted ANOVA on monthly minimum discharge
and stage as a function of time, for USGS stations in the Pearl River Basin.
Indicated are; the station number, a description of the location, the slope (change per
month), the value, the T value and the probability. The R2 is for the entire
seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Data prior to 1971
was used for this analysis.
Discharge Data (cubic metere/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl RiveT @ Bumside
ND



02482000
Pear! River @ Edinburg
NS



02482550
Peail River @ Carthage
0.089
0.416
2.406
0.0179
02483000
Tuscalameia Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
ND



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl RiveT @ Columbia
NS



02489500
Pearl River @ Bogalusa
NS



02490105
Bogue Lusa Creek @ Highway 439
NS



02490500
Bogue Chitto River @ Tylertown
-0.014
0.474
-10.680
0.0001
02492000
Bogue Chitto River @ Bush
-0.015
0.390
-4.292
0.0001
Stage Data (meters)
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
ND
02482550
Pearl River @ Carthage
ND
02483000
Tuscalameta Creek @ Walnut Grove
ND
02484500
Yockanookany River @ Ofahoma
ND
02484630
Pearl RiveT @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
-0.009
02488000
Pearl River @ Rockport
ND
02488500
Pearl River @ Monticello
ND
02488700
White Sand Creek @ Oak Vale
ND
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
ND
02492000
Bogue Chitto River @ Bush
ND
R2
Probability
0.3891
-3.396
0.0010
196

-------
Table A-8. Summary statistics from seasonally adjusted ANOVA on monthly maximum discharge
and stage as a function of time, for USGS stations in the Pearl River Basin.
Indicated are; the station number, a description of the location, the slope (change per
month), the value, the T value and the probability. The R2 is for the entire
seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Data prior to 1971
was used for this analysis.
Station
02481880
02482000
02482550
02483000-
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope	R2
Probability
Pearl River @ Bumside	ND
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl River @ Raicliff	ND
Hanging Moss Creek @ Jackson	ND
Pearl River @ Jackson	NS
Pearl River @ Rockport	1.559
Pearl River @ Monticello	NS
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	NS
Pearl River @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitto River @ Tylertown	NS
Bogue Chitto River @ Bush	NS
0.467
3.480
0.0007
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	ND
02482000	Pearl River @ Edinburg	ND
02482550	Pearl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
02488700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	ND
02492000	Bogue Chitto River @ Bush	ND
197

-------
Table A-9. Summary statistics from seasonally adjusted ANOVA on monthly mean discharge and
stage as a function of time, for USGS stations in the Pearl River Basin. Indicated
are; the station number, a description of the location, the slope (change per month),
the R.2 value, the T value and the probability. The R2 is for the entire seasonal
model, which includes sine and cosine terms to account for the annual signal.
Stations for which the model was not significant at the 95% level are indicated by the
symbol ns. The symbol nd indicates no data. Data for 1971-1988 was used for this
analysis.
Station
02481880
02482000
02482550
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope
Probability
Pearl River @ Bumside	ND
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl River @ Ratcliff	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Pearl River @ Rockport	NS
Pearl River @ Monticello	NS
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	NS
Pearl River @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitto River @ Tylertown	NS
Bogue Chitto River @ Bush	NS
Stage Data (meters)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.004
0.613
-3.749
0.0002
02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
-0.004
0.600
-5.018
0.0001
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
-0.004
0.548
-1.966
0.0508
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.002
0.466
-5.151
0.0001
02492000
Bogue Chitto River @ Bush.
ND



198

-------
Table A-10. Summary statistics from seasonally adjusted ANOVA on variance about the monthly
mean discharge and stage as a function of time, for USGS stations in the Pearl
River Basin. Indicated are; the station number, a description of the location, the
slope (change per month), the value, the T value and the probability. The R2 is
for the entire seasonal model, which includes sine and cosine terms to account for
the annual signal. Stations for which the model was not significant at the 95% level
are indicated by the symbol ns. The symbol nd indicates no data . Data for 1971-
1988 was used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
s
02481880
Pearl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto RiveT @ Bush
NS
R2
Probability
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	NS
02482000	Pearl River @ Gdinburg	NS
02482SS0	Pearl River @ Carthage	NS
02483000	Tuscalameta Creek @ Walnut Grove	NS
02484500	Yockanookany River @ Ofahoma	NS
02484630	Pearl River @ Ratcliff	ND
02S8S700	Hanging Moss Creek @ Jackson	NS
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	NS
02488500	Pearl River @ Monticello	NS
02488700	White Sand Creek @ Oak Vale	NS
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	NS
02492000	Bogue Chitto River @ Bush	NS
199

-------
Table A-11. Summary statistics from seasonally adjusted ANOVA of monthly minimum
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Data for 1971-1988
was used for this analysis.
Station
Location
Slope
02481880
Pearl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
¦ TuscalameLa Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Peail Rivei @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
0.001
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
-0.002
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meters/second)
R2
Probability
0.388
0.347
1.997	0.047
-2.393	0.0178
Stage Data (meters)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.002
0.603
-2.958
0.0035
02483000
Tuscalameta Creek @ Walnut Grove
0.001
0.418
3.498
0.0006
02484500
Yockanookany River @ Ofahoma
-0.003
0.605
8.971
0.0001
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
0.001
0.134
2.894
0.0049
02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
0.0002
0.1608
2.863
0.0097
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.001
0.552
-9.669
0.0001
02492000
Bogue Chitto River @ Bush
ND



200

-------
Table A-12. Summary statistics from seasonally adjusted ANOVA of monthly maximum
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Data for 1971-1988
was used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
02481880
Pearl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl RiveT @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
-0.028
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
R2
Probability
0.061
-2.719
0.0263


Stage Data (meters)



Station
Location
Slope
R2
T
Probabilit
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.005
0.508
-2.733
0.0069
02483000
Tuscalameta Creek @ Walnut Grove
-0.006
0.499
-3.474
0.0006
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
-0.002
0.224
-2.084
0.0387
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.004
0.300
-236
0.0194
02492000
Bogue Chitto River @ Bush
ND



201

-------
Table A-13. Summary statistics from seasonally adjusted ANOVA of monthly mean discharge
and stage as a function of time, for USGS stations in the Pearl River Basin.
Indicated are; the station number, a description of the location, the slope (change per
month), the value, the T value and the probability. The R2 is for the entire
seasonal model, which includes sine and cosine terms to account for the annual
signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The years 1974,
1979,1983 were deleted for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482530
Pearl River @ Carthage
NS



02483000
Tuscalameta Creek @ Walnut Grove
NS



02484S00
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
0.007
0.268
2.511
0.0128
02489000
Pearl River @ Columbia
-0.161
0.380
-1.940
0.053
02489500
i.
Pearl River @ Bogalusa
NS



02490105
Bogue Lusa Creek @ Highway 439
0.006
.200
2.567
0.0109
02490500
Bogue Chitto River @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
NS



Stage Data (meters)
Station
Location
Slope
R2
T
Probi bility
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
-0.004
0.611
-2.743
0.0068
02482550
Pearl River @ Carthage
-0.005
0.629
-4.256
0.0001
02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
-0.005



02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.002
0.442
-5.150
0.0001
02492000
Bogue Chitto River @ Bush
ND



202

-------
Table A-14. Summary statistics from seasonally adjusted ANOVA on variance about the monthly
mean discharge and stage as a function of time, for USGS stations in the Pearl
River Basin. Indicated are; the station number, a description of the location, the
slope (change per month), the R^ value, the T value and the probability. The R2 is
for the entire seasonal model, -which includes sine and cosine terms to account for
the annual signal. Stations for which the model was not significant at the 95% level
are indicated by the symbol ns. The symbol nd indicates no data. The years 1974,
1979,1983 were deleted for this analysis.
Station
Location
Slope
02481880
Pearl River @ Burmide
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monlicello
22.917
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bog&lusa
38.431
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue C Kit to River @ Tylenown
NS
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meters/second)
R2
Probability
0.125
0.128
2.223 0.0266
2.536	.0115
Station
Location
02481880
Pearl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
-0.002
02484500
Yockanookany River @ Ofahoma
-0.002
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monti cello
NS
02488700
White Sand Creek @'Oak Vale
NS
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
ND
Stage Data (meters)
Slope	R2
0.3048
0.2465
-2.251
-2.222
Probability
0.0258
0.0278
203

-------
Table A -15. Summary statistics from seasonally adjusted ANOVA on monthly minimum mean
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the R^ value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The years 1974,
1979,1983 were deleted for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
0.019
0.440
2.015
0.0449
02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Rate 11 ff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ MonticeUo
NS



02488700
White Sand Creek @ Oak Vale
0.004
0.479
9.054
0.0001
02489000
Pearl River @ Columbia
NS



02489500
Pearl River @ Bogalusa
NS



02490105
Bogue Lusa Creek @ Highway 439
0.002
0.320
4.614
0.0001
02490500
Bogue Chitto River @ Tylertown
-0.002
0.342
-3.191
0.00151
02492000
Bogue Chitto River @ Bush
NS





Stage Data (meters)



Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.002
0.632
-3.344
0.0010
02483000
Tuscalameta Creek @ Walnut Grove
0.001
0.377
3.494
0.0006
02484500
Yockanookany River @ Ofahoma
-0.003
0.705
=8.813
0.0001
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
0.001
0.161
3.562
0.0002
02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
ND



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
0.0002
0.134
2.055
0.0419
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.001
0.558
-9.306
0.0001
02492000 Bogue Chitto River @ Bush	ND

-------
Table A-16. Summary statistics from seasonally adjusted ANOVA on monthly maximum
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The years 1974,
1979,1983 were deleted for this analysis.
Station
Location
Slope
02481880
Pearl River @ Bunuide
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS •
02489000
Pearl River @ Columbia
-0.283
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meters/second)
R2
Probability
0.380
-2.065
0.0392
Stage Data (meters)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.006
0.513
-3.134
0.0021
02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
-0.007
0.511
-4042
0.0001
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
-0.002
0.226
-2.424
0.0167
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.005
0.278
-2.737
0.0070
02492000
Bogue Chitto River @ Bush
ND



205

-------
Table A-17. Summary statistics from regression analysis of annual mean discharge and stage as a
function of time, for USGS stations in the Pearl River Basin. Indicated are; die
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. The entire record was used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bunuide
NS



02482000
Petri River @ Edinburg
0.2730
0.094
6.05
0.0169
02482550
Pearl River @ Carthage
NS



02483000
Tuscalameta Creek @ Walnut Grove
0.1925
0.130
7.04
0.0109
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ RatclifT
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
0.5337
0.059
4.40
0.0395
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monti cello
1.7906
0.094
4.97
0.0306
02488700
White Sand Creek @ Oak Vale
0.1337
0.209
5.55
0,0314
02489000
Pearl River @ Columbia
-2.4997
0.129
4.01
0.0472
02489500
Pearl River @ Bogalusa
3.1097
0.134
7.13
0.0142
02490105
Bogue Lusa Creek @ Highway 439
0.1031
0.241
6.34
0.0222
02490500
Bogue Chitto River @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
NS



Stage Data (meters)
Station
Location
Slope
02481880
Pearl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
-0.0441
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
-0.0190
02492000
Bogue Chitto River @ Bush
ND
R2
0.317
0.393
T Probability
6.97
0.0185
7.32	0.0121
20*

-------
Table A-18. Summary statistics from regression analysis of variance about the annual mean
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the R^ value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. The entire record
was used for this analysis.
Discharge Data (cubic mcters/9ccond)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl Rivei @ Edinburg
82.574
0.073
4.72
0.0338
02482550
Pearl River @ Carthage
NS



02483000
Tuscalameta Creek @ Walnut Grove
31.287
0.101
5.30
0.0258
02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
NS



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
312.832
0.060
4.48
0.0378
02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
1423.65
0.116
6.30
0.0155
02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
NS



02489500
Pearl River @ Bogalusa
2384.82
0.159
8.72
0.005
02490105
Bogue Lusa Creek @ Highway 439
NS



02490500
Bogue Chitto River @ Tylartown
NS



02492000
Bogue Chitto River @ Bush
NS





Stage Data (meters)



Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
NS



02483000
Tuscalameta Creek @ Walnut Grove
NS



02484500
Yockanookany River @ Ofahoma
NS



02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
-0.0040
0.249
4.64
0.0492
02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
NS



02492000
Bogue Chitto River @ Bush
ND



207

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Table A-19. Summary statistics from regression analysis of annual minimum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. The entire record was used for this analysis.
Station
02481880
02482000
02482550
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope	R2
Pearl River @ Bumside	NS
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma 0.0072
Pearl River @ Ratcliff	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Pearl River @ Rockport	NS
Pearl River @ Monticello 0.0948
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	-0.4037
Pearl River @ Bogalusa 0.2952
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitto River @ Tylenown	NS
Bogue Chitto River @ Bush	NS
0.135
0.087
0.257
0.120
6.74
4.56
9.36
6.28
Probability
0.0129
0.0378
0.0050
0.0158
Stage Data (meters)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Bumside
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.0272
0.301
9.23
0.0083
02483000
Tuscalameta Creek @ Walnut Grove
0.0688
0.264
5.38
0.0349
02484500
Yockanookany River @ Ofahoma
-0.0255
0.363
8.55
0.0105
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockport
NS



02488500
Pearl River @ Monticello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylenown
-0.0111
0.346
7.42
0.0169
02492000
Bogue Chitto River @ Bush
ND



208

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Table A-20. Summary statistics from regression analysis of annual maximum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. The entire record was used for this analysis.
Discharge Data (cubic meters/second)
R2
Station
location
Slope
02481880
Pearl River @ Bunuide
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Raicliff
NS
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Montictllo
12.7252
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
17.9396
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
Probability
0.107
0.134
5.76
7.12
0.0203
0.0105
Stage Data (meters)
Station
Location
Slope
02481810
Pearl River- @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
+0.1561
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
ND
R2
Probability
0.215
6.58
0.0170
209

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Table A-21. Summary statistics from regression analysis of annual mean discharge and stage as a
function of time, for USGS stations in die Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Pre 1971 was used for this analysis.
Discharge Data (cubic meters/second)
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
3.873
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff

02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
12.007
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
R2
.908
T Probability
5.53
.0466
0.573
16.09	0.0012
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bunuide	ND
02482000	Pearl River @ Edinburg	ND
02482550	Peaxl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
0248 8700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	ND
02492000	Bogue Chitio River @ Bush	ND
210

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Table A-22. Summary statistics from regression analysis of variance about the annual
meandischarge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Pre i971 was used
for this analysis.
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
5200.90
02488500
Pearl River @ Moruicello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitlo River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meters/second)
R2
Probability
.635
20.87
0.006
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	ND
02482000	Pearl River @ Edinburg	ND
02482550	Pearl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River@ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	ND
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
02488700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	ND
02492000	Bogue Chitto River @ Bush	ND
211

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Table A-23. Summary statistics from regression analysis of annual minimum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Pre 1971 was used for this analysis.
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tusc&lameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
0.011
02484630
Pearl River @ RatclifT
ND
02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
-0.094
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meten/second)
R2
T Probability
0.150
4.76	0.0379
0.288
10.50	0.0033
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	ND
02482000	Perl River @ Edinburg	ND
02482550	Pearl River (3) Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ RatclifT	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl River @ Monticello	ND
02488700	White Sand Creek® Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	M)
02492000	Bogue Chitto River @ Bush	ND
212

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Table A-24. Summary statistics from regression analysis of annual maximum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine tenns to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Pre 1971 was used for this analysis.
Station
Location
Slope
02481880
Pearl River @ Bumside
ND
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
39.814
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
NS
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
ND
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Rockport
69.905
02488500
Pearl River @ Monticello
NS
02488700
While Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
NS
02489500
Pearl River @ Bogalusa
NS
02490105
Bogue Lusa Creek @ Highway 439
NS
02490500
Bogue Chitto River @ Tylertown
NS
02492000
Bogue Chitto River @ Bush
NS
Discharge Data (cubic meters/second)
R2
0.401
T Probability
5.36	0.0493
0.492
11.61
0.0052
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl RiveT @ Bumside	ND
02482000	Pearl River @ Edinburg	ND
02482550	Pearl River @ Carthage	ND
02483000	Tuscalameta Creek @ Walnut Grove	ND
02484500	Yockanookany River @ Ofahoma	ND
02484630	Pearl River @ RatcUff	ND
02585700	Hanging Moss Creek @ Jackson	ND
02486000	Pearl RiveT@ Jackson	NS
02488000	Pearl River @ Rockport	ND
02488500	Pearl RiveT @ Monticello	ND
02488700	White Sand Creek @ Oak Vale	ND
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chitto River @ Tylertown	ND
02492000	Bogue Chitto River @ Bush	ND
213

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Table A-25. Summary statistics from regression analysis of annual mean discharge and stage as a
function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Data for 1971-1988 was used for this analysis.
Station
02481880
02482000
02482S50
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope	R2
Probability
Pearl River @ Bumside	NS
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl River @ Ratcliff	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Peail River @ Roclcpon	NS
Pearl River @ Moniicello	NS
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	NS
Pearl River @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitto River @ Tyler town	NS
Bogue Chitto River @ Bush	NS
Stage Data (meters)
Station
Location
Slope
02481880
Pi arl River @ Bumside
NS
02482000
Pearl River @ Edinburg
NS
02482550
Pearl River @ Carthage
NS
02483000
Tuscalameta Creek @ Walnut Grove
NS
02484500
Yockanookany River @ Ofahoma
-0.049
02484630
Pearl River @ Ratcliff
ND
02585700
Hanging Moss Creek @ Jackson
NS
02486000
Pearl River @ Jackson
NS
02488000
Pearl River @ Roclcpon
NS
02488500
Pearl River @ Monticello
NS
02488700
White Sand Creek @ Oak Vale
NS
02489000
Pearl River @ Columbia
ND
02489500
Pearl River @ Bogalusa
ND
02490105
Bogue Lusa Creek @ Highway 439
ND
02490500
Bogue Chitto River @ Tylertown
-.0198
02492000
Bogue Chitto River @ Bush
NS
R2
T Probability
0.3173
6.97	0.0185
0.3433
7.32	0.0171
214

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Table A-26. Summary statistics from regression analysis of variance about the annual mean
discharge and stage as a function of time, for USGS stations in the Pearl River
Basin. Indicated are; the station number, a description of the location, the slope
(change per month), the value, the T value and the probability. The R2 is for the
entire seasonal model, which includes sine and cosine terms to account for the
annual signal. Stations for which the model was not significant at the 95% level are
indicated by the symbol ns. The symbol nd indicates no data. Data for 1971-1988
was used for this analysis.
Station
02481880
02482000
02482550
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope
Probability
Pearl River @ Bumside	NS
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl River @ RatclifT	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Pearl River @ Rockport	NS
Pearl RiveT @ Monticello	NS
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	NS
Pearl River @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitio River @ Tylertown	NS
Bogue Chitto River @ Bush	NS
Station	Location
02481880	Pearl River @ Bumside
02482000	Pearl River @ Edinburg
02482550	Pearl River @ Carthage
02483000	Tuscalameta Creek @ Walnut Grove
02484500	Yockanookany River @ Ofahoma
02484630	Pearl River @ RatclifT
02585700	Hanging Moss Creek @ Jackson
02486000	Pearl River @ Jackson
02488000	Pearl RiveT @ Rockpon
02488500	Pearl River @ Monticello
02488700	White Sand Creek @ Oak Vale
02489000	Pearl River @ Columbia
02489500	Pearl River @ Bogalusa
02490105	Bogue Lusa Creek @ Highway 439
02490500	Bogue Chitto River @ Tylertown
02492000	Bogue Chitto River @ Bush
Stage Data (meters)
Siope
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
-0.0039	0.249
ND
ND
ND
ND
ND
Probability
4.64
0.0492
215

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Table A-27. Summary statistics from regression analysis of annual minimum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Data for 1971-1988 was used for this analysis.
Station
02481880
02482000
02482550
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic meters/second)
Slope	R2
Probability
Pearl River @ Bumside	NS
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl River @ Ratcliff	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Pearl River @ Rockport	NS
Pearl River @ Moniicello	NS
White Sand Creek @ Oak Vale	NS
Pearl River @ Columbia	NS
Pearl RiveT @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitto RiveT @ Tylertown	NS
Bogue Chitto River @ Bush	NS
Stage Data (meters)
Station
Location
Slope
R2
T
Probability
02481880
Pearl River @ Burr side
NS



02482000
Pearl River @ Edinburg
NS



02482550
Pearl River @ Carthage
-0.0272
0.381
9.23
0.0083
02483000
Tuscalameta Creek @ Walnut Grove
0.0688
0.264
5.38
0.0349
02484500
Yockanookany River @ Ofahoma
.0.0255
0.363
8.55
0.0105
02484630
Pearl River @ Ratcliff
ND



02585700
Hanging Moss Creek @ Jackson
NS



02486000
Pearl River @ Jackson
NS



02488000
Pearl River @ Rockpon
NS



02488500
Pearl River @ Moniicello
NS



02488700
White Sand Creek @ Oak Vale
NS



02489000
Pearl River @ Columbia
ND



02489500
Pearl River @ Bogalusa
ND



02490105
Bogue Lusa Creek @ Highway 439
ND



02490500
Bogue Chitto River @ Tylertown
-0.0111
0.3464
7.42
0.0165
02492000
Bogue Chitto River @ Bush
NS



216

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Table A-28. Summary statistics from regression analysis of annual maximum discharge and stage
as a function of time, for USGS stations in the Pearl River Basin. Indicated are; the
station number, a description of the location, the slope (change per month), the
value, the T value and the probability. The R2 is for the entire seasonal model,
which includes sine and cosine terms to account for the annual signal. Stations for
which the model was not significant at the 95% level are indicated by the symbol ns.
The symbol nd indicates no data. Data for 1971-1988 was used for this analysis.
Station
02481880
02482000
02482550
02483000
02484500
02484630
02585700
02486000
02488000
02488500
02488700
02489000
02489500
02490105
02490500
02492000
Location
Discharge Data (cubic mews/second)
Slope	R2
Probability
Pearl River @ Bumside	NS
Pearl River @ Edinburg	NS
Pearl River @ Carthage	NS
Tuscalameta Creek @ Walnut Grove	NS
Yockanookany River @ Ofahoma	NS
Pearl RiveT @ Ratcliff	NS
Hanging Moss Creek @ Jackson	NS
Pearl River @ Jackson	NS
Pearl River @ Rockpon	NS
Pearl River @ Monticello	NS
White Sand Creek @ Oak Vale	NS
Pearl RiveT @ Columbia	NS
Pearl RiveT @ Bogalusa	NS
Bogue Lusa Creek @ Highway 439	NS
Bogue Chitlo River @ Tylertown	NS
Bogue Chitlo River @ Bush	NS
Stage Data (meters)
Station
Location
Slope
R2
Probability
02481880	Pearl River @ Bumside	NS
02482000	Pearl River @ Edinburg	NS
02482550	Pearl River @ Carthage	NS
02483000	Tuscalameta Creek @ Walnut Grove	NS
02484500	Yockanookany River @ Ofahoma	NS
02484630	Pearl River @ Ratcliff	ND
02585700	Hanging Moss Creek @ Jackson	NS
02486000	Pearl River @ Jackson	NS
02488000	Pearl River @ Rockport	NS
02488500	Pearl River @ Monticello	NS
02488700	White Sand Creek @ Oak Vale	NS
02489000	Pearl River @ Columbia	ND
02489500	Pearl River @ Bogalusa	ND
02490105	Bogue Lusa Creek @ Highway 439	ND
02490500	Bogue Chiuo River @ Tylenown	NS
02492000	Bogue Chitto River @ Bush	NS
217

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APPENDIX B
Breeding Bird Surveys, Pearl River Basin
219

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7 ^

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Table 1. Species, habitat, and regression on time, Breeding Bird Surveys, Pearl River basin

REGRESSION #
SPECIES
BBS NO.
HABITAT*
COL
LAC
LAKE
LUC
CYB
Chimney Swift
Chaetura pelapica
4230
F
ns
ns
ns
ns
-
Blue Gray Gnatcatcher
Polioplila caerulea
7510
F
ns
ns
ns
-
ns
Summer Tanaaer
Piranaa rubra
6100
F
ns
+
ns
ns
ns
Broad-Winged Hawk
Buteo platypterus
3430
F
ns


ns

Downy Woodpecker
Picoides pubescens
3940
F
ns
-
ns
ns
ns
Hairy Woodpecker
Picoides villosus
3930
F
ns

ns


Carolina Wren
Thryothorus ludivicianus
7180
F
ns
ns
ns
ns
ns
Tufted Titmouse
Parus bicolor
7310
F
ns
ns
ns
ns
ns
Brown Thrasher
Toxosloma rufum
7050
F
ns
ns
ns
ns
ns
Louisiana Waterthrush
Seiurus motacilla
6760
F
ns


ns

American Redstart
Setophaaa ruticilla
6870
F


ns
ns
ns
Brown-headed Nuthatch
Sitta pusilla
7290
F/FCC
ns
ns
ns
ns
ns
Turkey Vulture
Cathartes aura
3250
F/FD
+

+
ns
ns
Fish Crow
Corvus ossifragus
4900
F/FE
ns
ns

ns
+
Mississippi Kite
Ictinia mississippiensis
3290
F/FE
ns

ns
ns
ns
Black Vulture
Coraovps atratus
3260
F/FOC
ns

ns
ns
•
Prothonotary Warbler
Protonotaria citrea
6370
F/S
-
ns
ns
ns
ns
Yellow Billed Cuckoo
Coccvzus americanus
3870
roc
ns
ns
ns
+
ns
Acadian Flycatcher
Emoidonax virescens
4650
FCC
ns
+
ns
ns

Worm Eating Warbler
Helmitheros vermivorus
6390
FCC



ns

Swainson's Warbler
Limnothlypis swainsonii
6380
FCC
ns

ns
ns

Black & White Warbler
Mniotilta varia
6360
FCC



ns

Red-eyed Vireo
Vireo olivaceus
6240
FCC
+
ns
ns
ns
ns
Wood Thrush
Hylocichla mustelina
7550
FCC
ns

ns
-
ns
Barred Owl
Strix varia
3680
roc
ns


ns
ns
Chuck-Will's Widow
Caprimulgus carolinensis
4160
roc


ns


Pileated Woodpecker
Drvocopus pileatus
4050
FCC
ns
+
-
ns
ns
Baltimore Oriole
Icterus aalbula
5070
FX



ns

Red Cockaded Wooctoecker
Picoides borealis
3950
F0C
extinct?


Northern Bobwhite
Colinus virQinianus
2890
FD
ns I - I ns
ns
ns

-------
Cattle Egret
Bubulcus ibis
2001
FD




ns
Green Backed Heron
Butorides slriatus
2010
FD
ns
ns
ns
ns
ns

REGRESSION
SPECIES
BBS#
HABITAT*
COL
LAC
LAKE
LUC
CYB
Yellow-shafted Flicker
Colaptes auratus
4120
FD
ns
- ^
ns
ns

Bachman's Sparrow
Aimophila aestivalis
5750
FD

ns

ns

Field Sparrow
Spizella pusilla
5630
FD

ns
ns
+

Northern Rouah-winged Swallow
Stelgidopteryx ruficolllis
6170
FD
+


ns
ns
Eastern Meadowlark
Sturnella maana
5010
FD
-
-
ns
-
+
House Sparrow
Passer domesticus
6882
FD
ns

ns
ns
ns
Wild T urkev
Meleaaris aallopavo
3100
FD/FE
ns




Blue Grosbeak
Guiraca caerulea
5970
FD/FE
ns
ns
ns
ns
ns
Painted Buntina
Passerina ciris
6010
FD/FE





Indigo Bunting
Passerina cyanea
5980
FD/FE
ns

ns
+
+
American Crow
Corvus brachyrhynchos
4880
FD/FE
-
ns
ns
ns
+
Blue Jay
Cyanocitta cristata
4770
FD/FE
ns
ns
ns
ns
+
Barn Swallow
Hirundo rustica
6130
FD/FE
+

ns
ns

Red-winged Blackbird
Agelaius phoeniceus
4980
FD/FOC/S
ns
ns
+
ns
+
Killdeer
Charadrius vociferus
2730
FD/M
ns

ns

+
Chipping Sparrow
Spizella passerina
5600
FE

ns
ns
+

Yellow-Throated Warbler
Dendroica dominica
6630
FE
ns




Belted Kingfisher
Ceryle alcyon
3900
FE
ns
ns
ns
ns
ns
Loggerhead Shrike
Lanius ludovicianus
6220
FE
-
ns
ns
ns
ns
Northern Mockingbird
Mimus polyolottos
7030
FE
ns
ns
ns
-
ns
Carolina Chickadee
Parus carolinensfc
7360
FE/F
ns
ns
+
ns
+
Red Shouldered Hawk
Buteo lineatus
3390
FE/F
+
ns



Northern Cardinal
Cardinalis cardinalis
5930
FE/FCC/FOC
ns
ns
ns
ns
ns
Mourning Dove
Zenaida macroura
3160
FE/FD
ns
-
ns
ns
+
Red-Tailed Hawk
Buteo iamaicensis
3370
FE/FD





Eastern Kingbird
Tyrannus tvrannus
4440
FE/FD
-
ns
ns
ns
ns
Eastern Bluebird
Sialia sialis
7660
FE/FOC
ns

ns
+
ns
Eastern Wood Pewee
Contopus virens
4610
FCC
ns
ns
ns
ns
ns
Great-crested Flycatcher
Myarchus crinitus
4520
FOC
-
ns
ns
ns
ns
Ruby-Throated Hummingbird
Archilochus colubris
4280
FOC
ns
ns
ns

ns

-------
Pine Warbler
Dendroica pinus
6710
RX
ns
ns
ns
ns

Kentucky Warbler
Oporornis formosus
6770
RX
-
ns
+
ns

Northern Parula
Parula americana
6480
FOC
ns
+
ns
ns

Yellow-throated Vireo
Vireo flavi Irons
6280
RX
ns
+
ns
ns
ns

REI
3RESS
ION
SPECIES
BBS#
HABITAT*
COL
LAC
LAKE
LUC
CYB
White-eyed Vireo
Vireo Qriseus
6310
RX
ns
ns
ns
ns

Hooded Warbler
Wilsonia citrina
6840
RX
+
+
ns
ns
ns
Gray Catbird
Dumetella carolinensis
7040
PX


ns
+

Red-bellied Woodpecker
Melanerpes carolinus
4090
RX
ns
ns
+
ns
ns
Red-Headed Woodpecker
Aelanerpes erythrocephalus
4060
RX
ns
ns
ns
ns

European Starling
Sturnus vulgaris
4930
FOC/F/FD
ns
ns
ns
ns
ns
Yellow-breasted chat
Icteria virens
6830
FOC/FD
ns
ns
ns
ns
ns
Purple Martin
ProQne subis
6110
FOC/FD
ns
ns
+
ns
ns
American Robin
Turdus micjratorius
7610
FOC/FD/FE
ns
ns
+
ns
+
Orchard Oriole
Icterus spurius
5060
FOC/FE
-
rs
ns
-
+
Common Nighthawk
Chordeiles minor
4200
FOC/FE
ns
-
ns
ns
-
Prairie Warbler
Dendroica discolor
6730
FOC/FE
ns
+
ns
ns

Brown-headed Cowbird
Molothrus ater
4950
FOC/FE/FD
ns
ns
+
ns
ns
Common Grackle
Quiscalus auiscula
5110
FOC/FE/FD
-
ns
ns
-
ns
Common Yellowthroat
Geothlypis trichas
6810
FOC/FE/M
-
+
ns
-
ns
Rufus-sided Towee
Pipilo erythophthalmus
5870
FOC/FW
-
ns
ns
ns
ns
Wood Duck
Aix sponsa
1440
W
ns
ns
ns

ns
Great Blue Heron
Ardea herodias
1940
W
-

ns

ns
Little Blue Heron
Epretta caerulea
2000
W
+



ns
White Ibis
Eudocimus albus
1840
W
ns



ns
Yellow-Crowned Heron
Nycticorax violaceus
2030
W
ns

ns

ns
Great Egret
Casmerodius albus
1960
W
ns



ns
*	W - water; S - swamps and wet edges; M - marshes; FD = fields; FE - forest edges; F = forest in general;
closed canopy (usually interior, stenotopic species); and FOC = forest with an open canopy.
#	"+"= increasing population, decreasing population.

-------
Table 2. Species, habitat, and regression on time, Christmas Bird Counts, Pearl River basin

REGRESSION
SPECIES
HABITAT*
JACKSON#
Brown Creeper
Certhia americana
F
-
Tufted Titmouse
Parus bicolor
F
ns
Carolina Chickadee
Parus carolinensis
F
ns
Ruby-Crowned Kjnqlet
Repulus calendula
F
ns
Golden-crowned Kinalet
Recjulus satrapa
F
-
Red-breasted Nuthatch
Sitta canadensis
F
ns
American Robin
Turdus mipratorus
F
ns
Bald Eaale
Haliaeetus leucocephalus
F
+
Red-bellied Woodpecker
Melanerpes carolinus
F
ns
Red Cockaded Woodpecker
Picoides borealis
F
extinct?
Downy Woodpecker
Picoides pubescens
F
ns
Hairy Woodpecker
Picoides villosus
F
-
Yellow-bellied Sapsucker
Sphyrapicus varius
F
-
Northern Cardinal
Cardinalis cardenalis
F/FD
-
Turkey Vulture
Cathartes aura
F/FD
ns
Black Vulture
Coraavps atratus
F/FD
ns
Red-wing Blackbird
Aoelaius phoeniceus
F/FD/S
-
Bewicks Wren
Thryothorus bewikii
F/FE
ns
Blue Jay
Cvanocitta cristata
F/FE
ns
Northern Flicker
Colapates auratus
F/FE
-
Winter Wren
Troalodytes troalodvtes
F/S
-
Wild Turkey
Mereaaris aallopavo
FOC
ns
Pine Siskin
Carduelis pinus
FX
ns
Purple Finch
Carpodacus purpureus
FOC
ns
Hermit Thrush
Catharus outtatus
FCC
ns
Barred Owl
Strix varia
FCC
ns
Pileated Woodpecker
Dryocopus pileatus
FOC
ns
LeConts Sparrow
Ammodramus leconti
FD
ns
Brewers Blackbird
Euphaaus cyanocephalus
FD
ns
Savannah Sparrow
Passerculus sandwichensis
FD
-

-------
Field Sparrow
Spizella pusilla
FD
ns
Eastern Meadowlark
Sturnella magna
FD
-

REGRESSION
SPECIES
HABITAT*
JACKSON
Water Pipit
Anthus spinoletta
FD
ns
Marsh Wren
Cistothorus palustris
FD
ns
Sedge Wren
Cistothorus platensis
FD
ns
Palm Warbler
Dendroica palmarun
FD
ns
Horned Lark
Eremophilla alpestris
FD
+
Canada Goose
Branta canadensis
FD
+
Peregrine Falcon
Falco peregrines
FD/FE
ns
Least Sandpiper
Calidris minutilla
FD/M
ns
Killdeer
Charadrius vociferus
FD/M
ns
Common Snipe
Gallinago gallinago
FD/M
ns
Sora
Porzana Carolina
FD/M
ns
King Rail
Rallus eleaans
FD/M
+
Greater Yellowlegs
Tringa melanoleuca
FD/M
ns
Swamp Sparrow
Melospiza georgiana
FE
ns
Fox Sparrow
Passerella iliaca
FE
-
Vesper Sparrow
Pooecetes gramineus
FE
ns
Chipping Sparrow
Spizella passerina
FE
ns
European Starling
Sternus vulgarus
FE
ns
White-crowned Sparrow
Zonotrichia leucophrys
. FE
-
Northern Mockingbird
Mimus polygloltos
FE
ns
Eastern Bluebird
Sialia sialis
FE
+
Sharp-shinned Hawk
Accipiter striatus
FE
ns
Great Horned Owl
Bubo virginianus
FE
ns
Red-shouldered Hawk
Buteo lineatus
FE
+
American Kestrel
Falco sparverius
FE
ns
Fish Crow
Corvus ossifragus
FE/F
+
American Crow
Corvus brachyrhynchos
FE/F
+
Pidgeon (Rock Dove)
Columba
FE/FD
ns
Mourning Dove
Zenaida macrorua
FE/FD
ns
Northern Bobwhite
Colinus virginianus
FE/FD
-

-------
Lincolns Sparrow
Melospiza lincolnii
FE/FD
ns
Sonq Sparrow
Melospiza melodia
FE/FD
ns
House Sparrow
Passer domesticus
. FE/FD
-
Red-tailed Hawk
Buteo iamaicensis
FE/FD
ns

REGRESSION
SPECIES
HABITAT*
JACKSON
Yellow-rump Warbler
Dendroica coronata
FE/FOC
+
Cedar Waxwina
Bombvcilla cedrorum
PX
+
Western Medowlark
Sturnella nealecta
roc
ns
White-throat Sparrow
Zonotrichia albicollis
FCC
-
Loggerhead Shrike
Lanus iudovicianus
roc
ns
White-breasted Nuthatch
Sitta carolinensis
FOC
ns
Brown-headed Nuthatch
Sitta pusilla
RX
+
Carolina Wren
Thryothorus ludivicianus
PX
ns
House Wren
Troalodytes aedon
PX
+
Orange-crowned Warbler
Vermmivora celata
PX
ns
Solitary Vireo
Vireo solitarius
PX
ns
Brown Thrasher
Toxostoma rutum
PX
-
Eastern Screech Owl
Otus asio
PX
ns
American Woodcock
Scolopax minor
PX
ns
Red-headed Woodpecker
Melanerpes ervthrocephaius
PX
ns
American Goldfinch
Carduelis tristis
FOC/FD
-
Dark-eyed Junco
Junco hvemalis
FOC/FE
ns
Rufus-sided Towee
Piplo ervthroohthalmus
FOC/FE
-
Evening Grosbeak
Spiza americana
FOC/FE
ns
Common Yellowthroat
Geothlypis trichas
FOC/FE
ns
Brown-Headed Cowbird
Molothrus ater
FOC/FE/FD
ns
Common Grackle
Quiscalus auiscula
FOC/FE/FD
ns
Rusty Blackbird
Euphaaus carolinus
FOC/S
ns
Sharp-tailed Sparrow
Ammodramus caudacutus
M
ns
Seaside Sparrow
Ammodramus martimus
M
ns
Marsh Hawk
Circus cvaneus
M/FD
ns
Gadwall
Anas strepera
S
+
American Widgeon
Anas americana
W
ns

-------
Northern Shoveler
Anas dypeata
W
ns
Green-winqed Teal
Anas crecea
W
ns
Blue-winqeJ Teal
Anas discors
W
ns
American Black Duck
Anas rubripes
W
ns
Great Blue Heron
Ardea herodias
W
+
Lesser Scaup
Ay thy a affinin
W
ns

REGRESSION
SPECIES
HABITAT*
JACKSON
Redhead
Aythya americana
W
ns
Rinq-necked duck
Ay thy a collaris
W
ns
Great Scaup
Ay thy a m arila
w
ns
Canvasback
Aythya valisineria
w
ns
Buffle Head
Bucephalla albeola
w
+
Common Goldeneye
Bucephalla clanpula
w
ns
Great Eqret
Casmerodius albus
w
+
Snowy Eqret
Egretta thula
w
ns
Common Loon
Gavia immer
w
ns
Herrinq Gull
Larus argentatus
w
ns
Ring-billed Gull
Larus delawarensis
w
ns
Bonapartes Gull
Larus philidelphia
w
ns
Franklin's Gull
Larus pipixcan
w
+
Red-breasted Merqanser
Meraus senator
w
ns
Ruddy Duck
Oxura iamaicensis
w
ns
Great Comorant
Phalacrocorax
w
ns
Horned Grebe
Podiceps auritus
w
ns
Pied-billed Grebe
Podilymbus podiceps
w
ns
Forsters Tern
Sterna forsteri
w
ns
Common Tern
Sterna herundo
w
ns
Snow Goose

w
ns
Wood Duck
Anas dypeata
W/F
ns
Mallard
Anas platrhynchos
W/F
ns
Hooded Meraanser
Lophodvtes cudlatus
W/F
+
Cattle Eqret
Bubulcus ibis
W/FD
ns
American Coot
Flucia americana
W/FD
ns

-------
Eastern Phoebe
Sayornis phoebe
W/FE
ns
Belted Kingfisher
Cervle alvcon
W/FE
ns
Double-crested Comorant
Phalacrocorax auritus
W/S
+
*	W = water; S = swamps and wet edges; M = marshes; FO = fields; FE = forest edges;
F - forest in general; FCC - forest with closed canopy (usually interior, stenotopic
species); and FOC - forest with an open canopy.
#	"+"¦ increasing population, decreasing population.
K)
ro
oo

-------
APPENDIX C
Land Cover Classification Of Christmas Bird Count And Breeding Bird
Survey Sites In The Pearl River Basin
229

-------
Table 1. Temporal change in land cover of Christmas Bird Count and Breeding Bird
Survey sites, Pearl River basin .
Siis	Land cover	
Jackson agriculture/grassland
coniferous forest
mixed forest
deciduous forest
bottomland hardwood forest
forested wetland
water
barren/other
nonforested wedand
urban area
Lake	agriculture/grassland
coniferous forest
mixed forest
deciduous forest
bottomland hardwood forest
forested wedand
water
barren/other
nonforested wedand
urban area
Cybor	agriculture/grassland
coniferous forest
mixed forest
deciduous forest
bottomland hardwood forest
forested wetland
water
barren/other
nonforested wedand
urban area
Lacombe agriculture/grassland
coniferous forest
mixed forest
deciduous forest
bottomland hardwood forest
forested wetland
water
barren/other
nonforested wedand
urban area
1223	im
ha
%
ha
%
12332
30
8600
21
8069
20
7221
18
3725
9
4225
10
1775
4
5819
14
2725
7
3100
8
649
2
624
2
9987
24
10169
25
337
1
193
0
381
1
0
0
1306
3
1318
3
1300
38
1363
40
944
27
984
29
522
15
295
9
6
0
307
9
45
1
161
5
283
8
42
1
59
2
6
0
8
0
0
0
0
0
0
0
260
8
276
8
1828
52
2446
70
698
20
862
25
417
12
73
2
92
3
0
0
386
11
25
1
0
0
20
1
61
2
6
0
0
0
55
2
0
0
1
0
6
0
0
0
391
12
586
17
2772
82
2064
61
38
1
432
13
6
0
2
0
107
3
0
0
28
1
231
7
0
0
2
0
0
0
24
1
0
0
0
0
38
1
37
1
231

-------
Sits.
Land cover
J221
_12SL
_ac	2L.	ac	%
Columbia agriculture/grassland	1160	33	1066	31
coniferous forest	423	12	1023	29
mi^ed forest	1405	40	524	15
deciduous forest	0	0	398	11
bottomland hardwood forest	372	11	400	12
forested wedand	48	1	6	0
water	46	1	23	1
barren/other	4	0	37	1
nonforested wetland	2	0	0	0
urban area	18	1	0	0
Lucien agriculture/grassland	1285	38	1116	33
coniferous forest	755	22	927	27
mixed forest	748	22	745	22
deciduous forest	151	4	146	4
bottomland hardwood forest	370	11	421	12
forested wedand	0	0	0	0
water	54	2	10	0
bairen/other	3	0	10
nonforested wetland	0	0	0	0
urban area	47	1	47	1
1 Land cover was digitized 1/4 mile on either side of each 40-km Breeding Bird Survey
Route, and within a 24-kilometer diameter circle of the Christmas Bird Count Jackson
Site.
232

-------
APPENDIX D
Species List Of The Pearl River Basin
233

-------
MAMMALS
CASTORIDAE
American Beaver
CRICETIDAE
Marsh Rice Rat
Eastern Harvest Mouse
Fulvous Harvest Mouse
White-footed Mouse
Cotton Mouse
Golden Mouse
Hispid Cotton Mouse
Eastern Wood Rat
Pine Vole
Muskrat
MURIDAE
Black Rat
Norway Rat
House Mouse
CAPROMYIDAE
Nutria
CANIDAE
Coyote
Red Wolf
Red Fox
Gray Fox
URSIDAE
American Black Bear
PROCYONIDAE
Raccoon
MUSTELIDAE
Long-tailed Weasel
Mink
Spotted Skunk
Striped Skunk
River Otter
FELIDAE
Florida panther
Bobcat
CERVTDAE
White-tailed Deer
Castor canadensis
Oryzomys palustris
Reithrodontomys humulis
Reithrodontomys fulvescens
Peromuscus leucopus
Peromyscus gossypinus
Ochrotomys nuttalli
Sigmodon hispidus
Neotoma floridana
Pitymys pinetorom
Ondaira zibethicus
Rattusrattus
Rattus norvegicus
Mus musculus
Myocastor coypus
Canis beans
Canis rufus
Vulpes fulva
Urocyon cinereoargenteus
Ursus americanus
Procyon lotor
Mustela frenaia
Mus tela vison
Spilogale puiorius
Mephitis mephitis
Lutra canadensis
Felis concolor coryi
Lynx rufus
Odocoileus virginianus
235

-------
BIRDS
GAVTEDAE
Common Loon
PODICIPEDIDAE
Homed Grebe
Eared Grebe
Pied-billed Grebe
PELECANIDAE
White Pelecan
Brown Pelecan
SUIJDAE
Gannet
PHALACROCORACTOAE
Double-crested Cormorant
ANHINGIDAE
Anhinga
FREGAHDAE
Magnificient Frigatebird
ARDEIDAE
Great Blue Heron
Green Heron
Little Blue Heron
Cattle Egret
Reddish Egret
Great Egret
Snowy Egret
Louisiana Heron
Black-crowned Night Heron
Yellow-crowned Night Hero
Least Bittern
American Bittern
QCONIIDAE
Wood Stork
THRESKIORNITHIDAE
Glossy Ibis
White-faced Ibis
White Ibis
ANATTDAE
Whistling Swan
Canada Goose
White-fronted Goose
Snow Goose
Gaviaimmer
Podiceps auritus
Podiceps migricollis
Podifymbus podiceps
Pelecanus erythrorhynchos
Pelecanus occidentalis
Morns bassanus
Phalacrocorax auritus
Anhinga anhinga
Fregata magnificens
Ardea herodias
Butorides striaxus
Florida caerulea
Bub ulcus ibis
Dichromanassa rufescens
Casmerodius albus
Egretta thula
Hydranassa tricolor
Nyctiocorax nyctiocorax
Nyctanassa violacea
Ixobrychus exilis
Botaurus lentiginosus
Mycteria americana
Plegadis Falcinellus
Plegadis chihi
Eudocimus albus
Olor collumbianus
Branta canadensis
Anser albifrons
Chen caerilescens
236

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Fulvous Whistling-Duck
Mallard
Black Duck
Mottled Duck
Gadwall
Pintail
Green-winged Teal
Blue-winged Teal
American Widgeon
Northern Shoveler
Wood Duck
Redhead -
Ring-necked Duck
Canvasback
Greater Scaup
Lesser Scaup
Common Goldeneye
Buffelhead
Oldsquaw
White-winged Scoter
Surf Scoter
Black Scoter
Ruddy Duck
Hodded Merganser
Common Merganser
Red-breasted Merganser
catharhdae
Turkey Vulture
Black Vulture
accipitridae
Swallow-tailed Kite
Mississippi Kite
Sharp-shinned Hawk
Coopers Hawk
Red-tailed Hawk
Red-shouldered Hawk
Broad-winged Hawk
Harris' Hawk
Golden Eagle
Bald Eagle
Marsh Hawk
Dendrocygna bicolor
Anas platyrynchos
Anas rubripes
Anas fulvigula
Anas strepera
Anas acuta
Anas crecca
Anas discors
Anas americana
Anasctypeaia
Aix sponsa
Aythya americana
Aythya collaris
Aythya valisineria
Aythya marila
Aythya affinsis
Bucephala clangula
Bucephala albeola
Clangula hyemalis
Melanitta deglandi
Melanitta perspicillata
Melanitta nigra
Oxyura jamaicensis
Lophodytes cucullatus
Mergus merganser
Mergus senator
Cathartes aura
Coragyps atrants
Elanoides foroicatus
Ictinia mississippiensis
Accipiter striaius
Accipiter cooperi
Buteo jamaicensis
Buteo lineatus
Buteo platypterus
Parabuleo unicinctus
Aquila chrysaetos
Haliaeetus lucocephalus
Circus cyaneus
PANDIONIDAE
Osprey
FALCONE) AE
Arctic Peregrine Falcon
Merlin
American Kestrel
Pandion haliaetus
Falco peregrinus tundrius
Falco columbarius
Falco sparverius
237

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PHASIANIDAE
Bobwhite
MELEAGRIDIDAE
Turkey
GRUIDAE
Sandhill Crane
RALUDAE
King Rail-
Clapper Rail
Virginia Rail
Sora
Yellow Rail
Black Rail
Purple Gallinule
Common Gallinule
American Coot
CHARADRHDAE
Semipalmated Plover
Piping Plover
Snowy Plover
Wilson's Plover
Killdeer
American Golden Plover
Black-bellied Plover
SCOLOPACIDAE
Ruddy Turnstone
American Woodcock
Commor Snipe
Whimbrel
Upland Sandpiper
Spotted Sandpiper
Solitary Sandpiper
Greater Yellowlegs
Lesser Yellowlegs
Willet
Red Knot
Pectoral Sandpiper
White-rumped Sandpiper
Least Sandpiper
Dunlin
Semipalmated Sandpiper
Western Sandpiper
Sanderling
Short-billed Dowitcher
Long-billed Dowitcher
Stilt Sandpiper
Buff-breasted Sandpiper
Colinus virginianus
Meleagris gallopavo
Grus canadensis
Rallus elegans
Rallus longirostris
Rallus limnicola
Porzana Carolina
Coturnicops noveboracensis
Laterallus jamaicensis
Porphyrula martinica
Gallinula chloropus
Fuluca american
Charadrius semipalmaus
Charadrius melodus
Charadrius alexandrinus
Charadrius wilsonia
Charadrius vociferus
Pluvialus dominica
Pluvialus squatarola
Arenaria interpres
Philohela minor
Capella gallinago
Numenius phaeopus
Bartramia longicauda
Actitis macularia
Tringa solitaria
Tringa melanoleucas
Tringa flavipes
Catoptrophorus semipalmatus
Calidris camaus
Calidris melanotos
Canidris fuscicollis
Calidris rrurumlla
Calidris alpina
Calidris pusillus
Calidris mauri
Calidris alba
Limnodromus g rise us
Limnodromus scolopaceus
Micropalama himantopus
Tryngites subruficollis
238

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Marbled Godwit
Hudsonian Godwit
RECUR VIROSTRIDAE
American Avocet
Black-necked StUt
PHALAROPODIDAE
Wilson's Phalarope
Northern Phalarope
LARIDAE
Herring Gull
Ring-billed Gull
Laughing Gull
Bonaparte's Gull
Black-legged Kittiwake
Gull-billed Tem
Forester's Tern
Common Tern
Sooty Tem
Least Tem
Royal Tem
Sandwich Tem
Caspian Tem
Black Tem
RYNCHOPIDAE
Black Skimmer
COLUMBIDAE
Rock Dove
White-winged Dove
Mourning Dove
Ground Dove
CUCULIDAE
Yellow-billed Cuckoo
Black-billed Cuckoo
Groove-billed Ani
TYTONIDAE
Bam Owl
STRIGIDAE
Screech Owl
Great Homed Owl
Burrowing Owl
B aired Owl
Long-eared Owl
Sh on-eared Owl
Saw-whet Owl
CAPRIMULGEDAE
Limosafedoa
Limosa haemastica
Recurvirostra americana
Himantopus mexicanus
Steganopus tricolor
Lobipes lobatus
Larus argentatus
Larus delawarensis
Larus amcilla
Larus Philadelphia
Rissa tridactyla
Gelochelidon nilotica
Sterna forsteri
Sterna hirundo
Sterna fuscata
Sterna albifrons
Sterna maximus
Sterna sandvicensis
Sterna caspia
Chlidonias niger
Rynchops niger
Columba li\ia
Zenaida asiatica
Zenaida macroura
Columbina passerina
Coccyzus americanus
Coccyzus erythropthalmus
Crotophaga sulcirostris
Tytoalba
Otusasio
Bubo virginianus
Athene cunicularia
Strix varia
Asio otus
Asio flammeus
Aegolius acadicus
239

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Chuck-wills-widow
Whip-poor-will
Common Nighthawk
APODIDAE
Chimney Swift
TRQCHTT ,TDAE
Ruby-throated Hummingbird
ALCEDINIDAE
Belted Kingfisher
PICIDAE
Common Flicker
Pileated Woodpecker
Red-bellied Woodpecker
Red-headed Woodpecker
Yellow-bellied Sapsucker
Hairy Woodpecker
Downy Woodpecker
Red-cockaded Woodpecker
Ivory-billed Woodpecker*
TYRANNIDAE
Eastern Kingbird
Western Kingbird
Scissor-tailed Flycatcher
Great-crested Flycatcher
Eastern Phoebe
Say's Phoebe
Acadian Flycatcher
Eastern Wood Pewee
Olive-sided Flycatcher
Vermilion Flycatcher
ALAUDIDAE
Homed Lark
Caprimulgus carolinensis
Caprimulgus voctferus
Chordeiles minor
Chaeturapelagica
Archilochus colubris
Megaceryle alcyon
Colaptes auraxus
Dryocopus pileaius
Melanerpes carolinus
Melaneroes erythrocephalus
Sphyrapicus varius
Picoides vilbsus
Picoides pubescens
Picoides borealis
Campephilus principalis
Tyrannus tyrannus
Tyrannus verticalis
Muscivoraforficata
Myiarchus crinitus
Sayornis phoebe
Sayornissaya .
Empidonax virescens
Contopus virens
Nunallornis borealis
Pyrocephalus rubinus
Eremophila alpestris
~No verified reports but basin is within historical range of species.
HIRUNDINIDAE
Tree Swallow
Bank Swallow
Rough-winged Swallow
Bam Swallow
Cliff Swallow
Purple Martin
CORVIDAE
Blue Jay
Common Crow
Fish Crow
Tridoprocne bicolor
Riparia riparia
Stelgidopteryx ruficollis
Hirundo rustica
Petrochelidon pyrrhonota
Progne subis
Cyanocitta cristata
Corvus brachyrhynchos
Corvus ossifragus
240

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PAPIDAE
Carolina Chickadee
Tufted Titmouse
srrnDAE
White-breasted Nuthatch
Red-breasted Nuthatch
Brown-headed Nuthatch
CERTHIIDAE
Brown Creeper
TROGLODYTEDAE
House Wren
Winter Wren
Bewick's Wren
Carolina Wren
Long-billed Marsh Wren
Short-billed Marsh Wren
MIMTDAE
Mockingbird
Gray Catbird
Brown Thrasher
TURDIDAE
American Robin
Wood Thrush
Hermit Thrush
Swainson's Thrush
Gray-cheeked Thrush
Veery
Eastern Bluebird
SYLVUDAE
Blue-gray Gnatchatcher
Golden-crowned Kinglet
Ruby-aowned Kinglet
MOTACILLIDAE
Water Pipit
Sprague's Pipit
BOMB YCHUDAE
Cedar Wax wing
LANHDAE
Loggerhead Shrike
STURNIDAE
Starling
Parus carolinensis
Parus bicolor
Sitta carolinensis
Sitta canadensis
Sitta pusilla
Certhia familiaris
Troglodytes aedon
Troglodytes troglodytes
Thryomanes bewickii
Thryoihorus ludovicianus
Cistothorus palustris
Cistothorus plaiensis
Mimus polyglottos
Dwnetella carolinesis
Toxostoma rufum
Turdus migratorius
Hylocichla mustelina
Calharus guttata
Catharus ustulatus
Calharus minima
Catharus fuscescens
Sialia sialis
Poliopala caendea
Regulus satrapa
Regulus calendula
Anthus spinoletta
Anthus spragueii
Bombycilla cedorum
Lanius ludovicianus
Sturnus vulgaris
241

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VIREONIDAE
White-eyed Vireo
Bell's Vireo
Yellow-throated Vireo
Solitary Vireo
Red-eyed Vireo
Philadelphia Vireo
Warbling Vireo
PARULIDAE
Black-and-white Warbler
Prothonotaiy Warbler
Swainson's Warbler
Worm-eating Warbler
Golden-winged Warbler
Blue-winged Warbler
Bachman's Warbler*
Tenessee Warbler
Orange-crowned Warbler
Nashville Warbler
Northern Parula
Yellow Warbler
Magnolia Waibler
Cape May Warbler
Black-throated Blue Warbler
Yellow-rumped Warbler
Black-throated Green Warbler
Cerulean Warbler
Blackbumian Warbler
Yellow-throated Warbler
Chestnut-sided Warbler
Bay-breasted Warbler
Blackpoli Warbler
Pine Warbler
Kirtland's Warbler
Prairie Warbler
Palm Warbler
Overbird
Northern Waterthrush
Louisiana Waterthrush
Kentucky Warbler
Connecticut Warbler
Mourning Warbler
Common Yellowthroat
Yellow-breasted Chat
Hooded Warbler
Wilson's Warbler
Canada Warbler
American Redstart
Vireo griseus
Vireo bellii
Vireo flavifrons
Vireo solitarius
Vireo olivaceus
Vireo philadelphicus
Vireo gilvus
Mniotilta varia
Protonotaria citrea
Umnothlypis swainsonii
Helmitheros vermivorus
Vermivora chrysoptera
Vermivora pinus
Vermivora bachmanii
Vermivora peregrine
Vermivora celata.
Vermivora ruficapilla
Parula americana
Dendroica petechia
Dendroica magnolia
Dendroica ngrina
Dendroica caerulescens
Dendroica coronata
Dendroica virens
Dendroica cerulea
Dendroica fusca
Dendroica dominica
Dendroica pensytvanica
Dendroica castanea
Dendroica striata
Dendroica pinus
Dendroica Idrtlandii
Dendroica discolor
Dendroica pabnarum
Seiurus aurocapillus
Seiurus noveboracensis
Seiurus motacilla
Oporornis formusus
Oporornis agiiis
Oporornis Philadelphia
Geothlypis trichas
Icteria virens
Wilsonia citrina
Wilsonia pusilla
Wilsonia canadensis
Setophaga runcilla
* No verified reports but basin is within historical range of species.
PLOCEIDAE
House Sparrow	Passer domesticus
242

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ICTERIDAE
Bobolink
Eastern Meadowlark
Western Meadowlark
Yellow-headed Blackbird
Red-winged Blackbird
Orchard Oriole
Northern Oriole
Rusty Blackbird
Brewer's Blackbird
Boat-tailed Grackle
Common Grackle
Brown-headed Cowbird
THRAUPIDAE
Western Tanager
Scarlet Tanager
Summer Tanager
FRINGILLEDAE
Cardinal
Rose-breasted Grosbeak
Black-headed Grosbeak
Blue Grosbeak
Indigo Bunting
Painted Bunting
Dickcissel
Evening Grosbeak
Purple Finch
Pine Siskin
American Goldfinch
Rufous-sided Towhee
Lark Bunting
Savannah Sparrow
Grasshopper Sparrow
Sharp-tailed Sparrow
Seaside Sparrow
Vesper Sparrow
Lark Sparrow
Bachman's Sparrow
Dark-eyed J unco
Chipping Sparrow
Clay-colored Sparrow
Field Sparrow
Harris' Sparrow
White-crowned Sparrow
White-throated Sparrow
Fox Sparrow
Lincoln's Sparrow
Swamp Sparrow
Song Sparrow
Lapland Longspur
Dolichonyz oryzivorus
Sturnella magna
Sturnella neglecta
Xanthocephalus xanthocephalus
Agelaius phoeniceus
Icterus spurius
Icterus galbula
Euphagus carolinus
Euphagus cyanocephalus
Quiscalus mexicanus
Quiscalus quiscula
Molothrus ater
Piranga ludoviciana
Piranga olivacea
Piranga rubra
Cardinalis cardinalis
Pheucticus ludovicianus
Pkeucticus melanocephalus
Guiraca caerulea
Passerina cyanea
Passerina ciris
Spiza americana
Hesperiphona vespertina
Carpodacus purpureus
Carduelis spinas
Carduelis tristis
Pipilo erythrophthalmus
Calamospiza melanocorys
Passer cuius sandwichensis
Ammodramus savannarum
Ammospiza caudacuta
Ammospiza maritima
Pooecetes gramineus
Chondestes grammacus
Aimophila aestivalis
J unco hyemalis
Spizella passerina
Spizella pallida
Spizella pusilla
Zonotrichia querula
Zonotrichia leucophrys
Zonotrichia albicollis
Passerella iliaca
Melospiza lincolrdi
Melospiza georgiana
Melospiza melodia
Calcarius lapponicus
243

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REPTILES
ALLIGATORIDAE
American Alligator	Alligator mississippiensis
CHELYDRIDAE
Snapping Turtle
Alligator Snapping Turtle
KINOSTERNIDAE
Common Musk Turtle
Stripe-necked Musk Turtle
Razor-backed Musk Turtle
Eastern Mud Turtle
Mississippi Mud Turtle
EMYDIDAE
Alabama Map Turtle
Mississippi Map Turtle
Ringed Sawback
Mississippi Diamondback Terrapin
Southern Painted Turtle
Slider
Mobile Cooter
Missouri Slider
Red-eared Pond Slider
Yellow-bellied Turtle
Three-toed Box Turtle
Eastern Chicken Turtle
TESTUDINIDAE
Gopher Tortoise
TRIONY CHIDAE
Gulf Coast Smooth Softshell
Gulf Coast Spiney Softshell
IGUANIDAE
Green Anole
Northern Fence Lizard
Southern Fence Lizard
SCINCIDAE
Ground Skink
Five-lined Skink
Broad-headed Skink
Southeastern Five-lined Skink
Southern Coal Skink
TEIIDAE
Six-lined Racerunner
Chetydra serpentina
Macroclemys temmincki
Sternotherus odoratus
Sternotherus minor peltifer
Sternotherus carinatus
Kinosternon subrubrum subrubrum
Kinosternon subrubrum hippocrepis
Graptemys pulchra
Graptemys kohni
Graptemys oculifera
Malaclemys terrapin pileata
Chrysemys picta dorsalis
Chrysemys concinna hieroglyphica
Chrysemys concinna mobilensis
Chrysemys floridana hoyi
Chrysemys scripta elegans
Chrysemys scripta scripta
Terrapene Carolina triunguis
Dierochetys rencularia reucularia
Gopherus polyphemus
Trionyx muticus calvatus
Trionyx siniferus asperus
Anolis carolinensis carolinensis
Sceloporus undulatus hyacinthinus
Sceloporus undulatus undulatus
Scincella lateralis
Eumeces faciatus
Eumeces laticeps
Eumeces inexpectatus
Eumeces anthracinus pluvialus
Cnemidophorus sexlineatus sexlineatus
244

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ANGUIDAE
Eastern Glass Lizard
Eastern Slender Glass Lizard
COLUBRIDAE
Banded Water Snake
Broad-banded Water Snake
Gulf Coast Salt Marsh Snake
Green Water Snake
Gulf Coast Glossy Water Snake
Delta Glossy Water Snake
Midland Water Snake
Yellow-bellied Water Snake
Diamondback Water Snak
Queen Snake
Eastern Garter Snake
Eastern Ribbon Snake
Western Ribbon Snake
Rough Earth Snake
Western Smooth Earth Snake
Yellow-lipped Snake
Northern Red-bellied Snake
Midland Brown Snake
Marsh Brown Snake
Eastern Hognose Snake
Midwest Worm Snake
Mississippi Ringneck Snake
Rough Green Snake
Rainbow Snake
Western Mud Snake
Southern Black Racer
Eastern Coachwhip
Eastern Indigo Snake
Black Pine Snake
Gray Rat Snake
Com Snake
Northern Scarlet Snake
Scarlet Kingsnake
Pale Milk Snake
Mole Snake
Speckled Kingsnake
Southeastern Crowned Snake
IPERIDAE
Western Cottonmouth
Southern Copperhead
Western Pygmy Rattlesnake
Dusky Pygmy Rattlesnake
Canebrake Rattlesnake
ELAPIDAE
Eastern Coral Snake
Ophisaurus ventralis
Ophisaurus attenuatus longicaudus
Natrixfasciaia fasciata
Natrix fasciiata confluens
Matrix fasciata clarki
Natrix cyclopion cyclopion
Natrix rigida sinicola
Natrix rigida dehae
Nerodia sipedon pleuralis
Nerodia erythrogasterflavigaster
Nerodia rhombifera rhombifera
Regina septemvittata
Thamnophis sirtalis sirtalis
Thamnophis sauritus sauritus
Thamnophis proximus proximus
Virginia striatula
Virginia valeriae elegans
Rhadinaae flavitata
Storeria occipitomaculata
Storeria dekayi wrighttorum
Storeria dekayi limnetes
Heterodon platyrhinos
Carophophis amoenus helenae
Diadophis punctatus stictogenys
Opheodrys aestivus
Farancia erytrograrrana erytrogranvna
Farancia abacura reimvardn
Coluber constrictor priapus
Masticophis flagellum flagellum
Drymarchon corais couperi
Pituophis melanoleucus lodingi
Elaphe obsoleta spiloides
Elaphe guttata guttata
Cemophora coccinea copei
Lampropeltis triangulum elapsoides
Lampropeltis triangulum multistrata
Lampropeltis calligaster rhombomaculta
Lampropeltis getuJus holbrooki
Tantilla coronata
Agkistrodon piscivorus leucostoma
Agkistrodon contortrix contortrix
Sistrurus miliarius streckeri
Sistrurus miliarius barbouri
Crotalus horridus atricaudatus
Micrurus fulvius fulvius
245

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AMPHIBIANS
SIRENIDAE
Western Lesser Siren
AMPIUMIDAE
Three-toed Amphiuma
Two-toed Amphiuma
NECTURIDAE
Gulf Coast Waterdog
Alabama Waterdog
SALAMANDRIDAE
Central Newt
AMBYSTOMAUDAE
Mole Salamander
Small-mouthed Salamander
Eastern Tiger Salamander
Spotted Salamander
Marbled Salamander
PLETHODONTIDAE
Spotted Dusky Salamander
Southern Dusky Salamander
Southern Red Salamander
Gulf Coast Mud Salamander
Slimy Salamander
Zig Zag Salamander
Four-toed Salamander
Southern Two-lined Salamander
Three-lined Salamander
Dwarf Salamander
PELOBATTDAE
Eastern Spadefoot Toad
EICROHYLIDAE
Eastern Narrow-mouthed Toad
BUFOMDAE
American Toad
Southern Toad
Fowler's Toad
Oak Toad
Siren intermedia nettingi
Amphiuma tridactylum
Amphiuma means
Necturus beyeri
Necturus alabamensis
Notophthalmus viridescens louisianensis
Ambysioma talpoideum
Ambystoma texanum
Ambystoma tigrinum tigrinum
Ambystoma maculatum
Ambystoma spacum
Desmoganthus fuscus conanti
Desmoganthus auriculatus
Pseudotriton ruber vioscai
Pseudotriton montanus flavissimus
Plethodon glutinosus glutinosus
Plethodon dorsalis dorsalis
Hemidactylium scutatum
Eurycea bislineata cirrigera
Eurycea longicauda guttolineata
Eurycea quadridigitatc.
Scaphipus holbrooki holbrooki
Gastrophryne carolinensis
Bufo americanus americanus
Bufo terrestris
Bufo woodhousei fowleri
Bufo quercicus
HYLIDAE
Barking Treefrog	Hyla graaosa
Northern Spring Peeper	Hyla crucifer crucifer
Green Treefrog	Hyla cinerea
Western Bird-voiced Treefrog	Hyla avivoca avivoca
Squirrel Treefrog	Hyla squirella
246

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Pine Woods Treefrog
Gray Treefrog
Gray Treefrog
Ornate Chorus Frog
Southern Chorus Frog
Upland Chorus Frog
Northern Cricket Frog
Southern Cricket Frog
RANIDAE
Bronze Frog
Pig Frog
Bullfrog
Southern Leopard Frog
Pickeral Frog
Northern Crawfish Frog
Dusky Gopher Frog
Hylafemoralis
Hyla versicolor
Hyla chrysoscelis
Pseudacris ornata
Pseudacris nigrita nigrita
Pseudacris triseriata feriarum
Acris crepitans crepitans
Acris gryllus gryllus
Rana climitans climitans
Ranagrylio
Rana catesbeiana
Rana utricularia
Rana palustris
Rana areolata circulosa
Rana areolata sevosa
247

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FISHES
PETROMYZONHDAE
Chestnut Lamprey
Southern Brook Lamprey
Least Brook Lamprey
ACIPENSERIDAE
Atlantic Sturgeon
POLY ODONTIDAE
Paddleflsh-
AMHDAE
Bowfm
LEP1S OSTEID AE
Spotted Gar
Longnose Gar
Alligator Gar
ELOPIDAE
Tarpon
CLUPEIDAE
Alabama Shad
Largescale Menhaden
Skipjack Herring
Gizzard Shad
Threadfin Shad
ENGRAULIADAE
Bay Anchovy
ESOCIDAE
Grass Pickerel
Chain Pickerel
HIODONTIDAE
Mooneye
CATOSTOMIDAE
Quillback
Highfin Carpsucker
Blue Sucker
Creek Chubsucker
Lake Chubsucker
Sharpfin Chubsucker
Hogsucker
Smallmouth Buffalo
Spotted Slacker
River Sucker
Blacktail Redhorse
Ichthyomyzon castaneus
Ichthyomyzon gagei
Okkelbergia aepyptera
Acipenser oxyrhynchus
Polyodon spathula
Amia calva
Lepisosteus oculatus
Lepisosteus osseus
Lepisosteus spathula
Megalops atlanaca
Alosaalabamae
Brevoortia pan-onus
Alosa chrysochloris
Dorosoma cepedianum
Dorosoma petenense
Anchoa mitchilli
Esox americanus
Esox niger
Hiodon tergisus
Carpiodes cyprinus
Carpiodes velifer
Cycleptus elongatus
Erimyzon oblongus
Erimyzon sucetta
Erimyzon tenuis
Hypentelium nigricans
Ictiobus bubalus
Minytrema melanops
Moxostoma carinarum
Moxostoma poecilurum
24*

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CYPRINIDAE
Carp
Silveijaw Minnow
Cypress Minnow
Silvery Minnow
Speckled Chub
Bigeye Chub
Silver Chub
Bluehead Chub
Golden Shiner
Emerald Sniner
Bluntface Shiner
Ironcolor Shiner
Common Shiner
Longnose Shiner
TailUght Shiner
Rosyfin Shiner
Flagfin Shiner
Weed Shiner
Blacktail Shiner
Mimic Shiner
Bluenose Shiner
Pugnose Minnow
Bluntnose Minnow
Bullhead Minnow
Creek Chub
ARUDAE
Sea Catfish
ICTALURIDAE
Blue catfish
Black Bullhead
Yellow Bullhead
Channel Catfish
Black Madtom
Tadpole Madtom
Speckled Madtom
Brindled Madtom
Frecklebelly Madtom
Freckled Madtom
Flathead Catfish
ANGUILLIDAE
American Eel
BELONIDAE
Atlantic Needlefish
SYNGNATHIDAE
Gulf Pipefish
Cyprinus carpio
Ericymba buccata
Hybognathus hayi
Hybognathus nuchalis
Hybopsis aestivalis
Hybopsis amblops
Hybopsis storeriana
Nocomis leptocephalus
Notemigonum crysoleucas
Notropis atherinoides
Notropis camprus
Notropis chalybaeus
Notropis chrysocephalus
Notropis longirostris
Notropis maculatus
Notropis roseipinnis
Notropis signipinnis
Notropis texanus
Notropis venustus
Notropis volucellus
Notropis welaka
Opsopoeodus emiliae
Pimephales notatus
Pimephales vigilax
Semotilus atromaculatus
Arius felis
Ictalurus furcatus
Ictalurus melas
Ictalurus natalis
Ictalurus punctatus
Noturus funebris
Noturus gyrinus
Noturus leptacanthus
Noturus miurus
Noturus munitus
Noturus nocturnus
Pylodictis olivaris
Anguilla rostrata
Strongylura marina
Syngnathus scovelli
249

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CYPRIN ODONTIDAE
Northern Studfish
Golden Topminnow
Blackstripe Topminnow
Starhead Minnow
Blackspotted Topminnow
POECTI .TTDAE
Mosquitofish
Least Killifish
Sailfin Molly
APHREDODERIDAE
Pirate Perch
ATHERINIDAE
Brook Silverside
Tidewater Silverside
MUGILIDAE
Striped Mulled
PERCICHTHYEDAE
Yellow Bass
Striped Bass
CENTRARCHIDAE
Rockbass
Flier
Banded Pygmy Sunfish
Warmouth
Green Sunfish
Orangespotted Sunfish
Bluegill
Dollar Sunfish
Longear Sunfish
Redear Sunfish
Spotted Sunfish
Bantam Sunfish
Spotted Bass
Largemouth Bass
White Crappie
Black Crappie
PERQDAE
Crystal Darter
Naked Sand Darter
Scaly Sand Darter
Fundulus catenatus
Fundulus chrysotus
Fundulus notatus
Fundulus norti
Fundulus olivaceus
Gambusia affinis
Heterandriaformosa
Poecilia kaipinna
Aphredoderus sayanus
Labidesthes sicculus
Menidia beryUina
Mugil cephalus
Morone mississippiensis
Morone saxatilis
Ambloplites rupestris
Centrarchus macropterus
Elassoma zonatum
Chaenobryttus gulosus
Lepomis cyanellus
Lepomis humilis
Lepomis macrochirus
Lepomis marginatus
Lepomis megalotis
Lepomis microlophus
Lepomis punctatus
Lepomis symmetricus
Micropterus punctulaius
Micropterus salmoides
Pomoxis annularis
Pomoxis nigromaculatus
Ammocrypta asperella
Ammocrypta beani
Ammocrypta vivax
250

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MUSSELS
amblenddae
Amblema plicata perplicata
Fusconaia ebena
Fusconaia cerina
Fusconaia rubida
Fusconaia chickasawhensis
Plectomerus dombeyanus
Quadrula apiculata aspera
Quadrula pustulosa
Quadrula refulgens
Quadrula mononi
Tritogonia verrucosa
Megabnaias nervosa
UNION ID AE
Elliptio crassidens crassidens
Uniomerus tetralasmus
Uniomerus declivus
Anodoraa imbecillis
Anodoraa grandis corpulenta
Lasmigonia complanaia
Glebula rotundata
Lampsilis teres teres
Lampsilis teres anodontoides
Lampsilis straminea daibornensis
Leptodea fragilis
Potamilus purpuratus
Ligumia subrostrata
Obovaria jacksoniana
Obovaria unicolor
Villosa lienosa lienosa
Obliquaria reflexa
251

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PLANTS
PINACEAE
Loblolly Pine
Longleaf Pine
Shortleaf Pine
Slash Pine
TAXODIACEAE
Bald Cypress
TYPHACEAE
cattail
POTAMOGENTONACEAE
pondweed
RUPPIACEAE
Widgeon Grass
NAJADACEAE
Southern Najad
ALIS MATACEAE
Arrowhead
Bulltongue
HYDROCHARITACEAE
Wild Celery
POACEAE
Bermuda Grass
bluestem
cord grass
Big Cordgrass
Saltmeadow Cordgrass
Com
Dallis Grass
fescue
Maidencane
Sorghrum
Wild Millet
CYPERACEAE
Sawgrass
Southern Bullrush
ARACEAE
Golden Club
peltandra
LEMNACEAE
duckweed
Pinus taeda
Pinus palustris
Pinus echinata
Pinus elliottii
Taxodium distichum
Typha sp.
Pontamogeton sp.
Ruppia mariiima
Najas guadalupensis
Sagittaria sp.
Sagittaria lancifolia
Vallisneria americana
Cynodon dactylon
Andropogon sp.
Spartina sp.
Spartina cynosuroides
Spartina altemiflora
Zeamays
Paspalum dialatatum
Festuca sp.
Panicum hemitomon
Sorghrum vulgare
Echinochloa walteri
Cladium jamaicensis
Scirpus californicus
Oroniium aquaticum
Peltandra sp.
Lemna sp.
252

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PONTEDERIACEAE
Pickerelweed
Water Hyacinth
JUNCACEAE
Needle Rush
LILIACEAE
smilax
SALICACEAE
Black Willow
JUGLANDACEAE
hickory
Biner Pecan
Bittemut Hickory
Shagbark Hickory
Swamp Hickory
FAGACEAE
Blackjack Oak
Laurel Oak
Northern Red Oak
Nuttal Oak
Overcup Oak
Post Oak
Scrub Oak
Shumard Oak
Southern Red Oak
Swamp Chestnut Oak
Water Oak
Willow Oak
ULMACEAE
elm
American Elm
Slippery Elm
Winged Elm
Sugar berry
AMARANTHACEAE
Alligator Weed
CERATOPHYLLACEAE
Coontail
CABOMACEAE
Fanwort
MAGNOLIACEAE
Sweetbay
Yellow Poplar
Pontederia cordata
Eichhornia crassipes
Juncus roemerianus
Smilax sp.
Salix nigra
Carya sp.
Carya aquanca
Carya cordiformis
Carya ovata
Carya leiodermis
Quercus marilandica
Quercus laurifolia
Quercus rubra
Quercus nuttallii
Quercus lyrata
Quercus stellata
Quercus ilicifolia
Quercus shumardii
Quercus falcata
Quercus michauxii
Quercus nigra
Quercus phellos
Ulmus sp.
Ulmus americana
Ulmus rubra
Ulmus alata
Ulmus laevigata
Alternantnera philoxeroides
Ceratophyllum demersum
Cabomba caroliniana
Magnolia virginiana
Liriodendron tulipifera
253

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HAMAMFIJDACEAE
Sweetgum
PLATANACEAE
Sycamore
ROSACEAE
blackberry
Black Cherry
FABACEAE
lespedeza
Redbud
Sericea
Soybean
ANA CARD IACEAE
sumac
Poison Oak
ACERACEAE
Boxelder
Red Maple
Drummond Red Maple
MALVACEAE
Cotton
Rose Mallow
VIOLACEAE
violets
NYSSACEAE
Tupelo Gum
CORNACEAE
dogwood
Flowering Dogwood
Roughleaf Dogwood
ERICACEAE
Sourwood
EBENACEAE
Persimmon
OLEACEAE
Green Ash
GENTIANACEAE
Pennywort
Liquidambar styraciflua
Platanus occidentalis
Rubus sp.
Prunus serotina
Lespedeza sp.
Cercis canadensis
Lespedezacuneata
Glycine max
Rhus sp.
Rhus toxicdendron
Acer negundo
Acer rubrum
Acer rubrum var. drwnmondii
Gossypium hirsutum
Hibiscus rmlitaris
Viola sp.
Nyssa aquatica
Cornus sp.
Cornus florida
Cornus drummondii
Oxydendrum arboreum
Diospyrus virginiana
Fraxinus pennsylvanica
Obolaria virginica
254

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LENTIBULARIACEAAE
bladderwort
Utricularia sp.
RUBIACEAE
Buttonbush
CAPRIFOLIA CEAE
honeysuckle
ASTERACEAE
asters
goldenrod
ragweed
Bitterweed
Source: Fish and Wildlife Service (1981).
Cephalanthus occidentalis
Lonicera sp.
Aster sp.
Solidago sp.
Ambrosia sp.
Helenium amarum
255

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APPENDIX E
Habitat Preference Of Endangered And Threatened Species Occurring In
The Pearl River Basin
257

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Common Name	Habitat preference
Fish
Atlantic Sturgeon
Frecklebelly Madtom
Crystal Darter
Freckled Darter
Reptiles
Ringed Sawbacked Turtle
Southern Coal Skink
Southern Hognose Snake
Rainbow Shake
Eastern Indigo Snake
Black Pine Snake
American Alligator
Anadromous. Spawning occurs along gulf coastal
streams over gravel beds in spring.
Found in shallow riffle areas over a gravel bottom in
moderate to strong current streams and rivers.
Occurs over sand or gravel bottom in strong flowing
current of large sandy creeks and rivers.
Large river form. Fast-flowing current in deep
water. Uncommon in tributaries of larger streams.
Aquatic. Associated with flowing streams and rivers
leaving only to lay eggs and bask. Known only
from Pearl River system.
Occurs in hilly terrain and mixed pine-hardwood
forests near water. Known from sandy soils and
rocky areas usually under logs or rocks.
Found in sandy open habitat Frequents sandy
woods, fields and groves, river flooding plains, and
hardwoods hammocks.
Usually found in or near streams. Frequents stream
banks and ponds where it forages. May burrow in
sandy soil near water. Streams passing through
swamps favorite habitat.
Usually found in desolate areas where gopher
tortoise burrows occur close to streams or swamps.
Encountered most frequently in xeric habitats.
Chiefly found in longleaf pine-turkey oak or sandhill
associations and mixed pine-hardwood forests.
Occurs in swamps, lakes, sloughs, and sluggish
streams.
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Birds
Brown Pelican
Southern Bald Eagle
Artie Peregrine Falcon
Red-cockaded Woodpecker
Ivory-billed Woodpecker
Cliff Swallow
Bachman's Warbler
Mammals
Red Wolf
Black Bear
Florida Panther
Coastal bays and beaches.
Chiefly found along coasts and large rivers.
Associated with hardwood forests along waterways.
Coastal bays and beaches, mountains, and
woodlands.
Mature, open pine forests. Understory if present,
usually under two meters.
Mature bottomland deciduous hardwood forests and
cypress swamps.
Open pastures, meadows, and marshes. Nests under
culverts and bridges.
Bottomland hardwood and moist deciduous forests.
Mature bottomland hardwood forests, coastal
prairies, and marshes.
Mature bottomland forests and swamps.
Mature bottomland hardwood forests, swamps, and
upland forests.
Data from U.S. Fish and Wildlife Service (1981).
EPA Library Region 4
1024363

library
us EPA Region 4
AFC/9th FL Tower
61 Forsyth St. S.W.
Atlanta, GA 30303-3104
7
DATE BUI
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