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Chesapeake Bay 2005
Health and Restoration Assessment
Part One: Ecosystem Health
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iere are a number of smaller-scale success stories, the overall ecosystem health of the Chesapeake
is degraded. For more than twenty years, on the ground restoration efforts have managed to offset
of the region's growing population while making modest ecological gains in some areas. Major poliu-
lon, habitat restoration, fisheries management and watershed protection actions taken to date have
in sufficient to restore the health of the Bay.
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Chesapeake Bay Program
A Watershed Partnership
The Chesapeake Bay Program brings
together local, state and federal gov-
ernments, non-profit organizations,
watershed residents and the region's
leading academic institutions in a
partnership effort to protect and re-
store the Bay.
Through a series of Chesapeake Bay
agreements, Bay Program signato-
ries - the state of Maryland; the com-
monwealths of Pennsylvania and Vir-
ginia; the District of Columbia; the
U.S. Environmental Protection Agency
representing the federal government;
and the Chesapeake Bay Commis-
sion representing Bay state legislators
- have committed to reducing pollu-
tion, restoring habitat and sustainably
managing fisheries. Since 2000, the
headwater states of Delaware, New
York and West Virginia have joined
in regional efforts to improve water
quality.
To learn more and find out how you
can help, visit the Chesapeake Bay
Program website at www.chesapeake-
bay.net.
Chesapeake Bay Program
410 Severn Avenue, Suite 109
Annapolis, MD 21403
(800) YOUR BAY
www.chesapeakebay.net
Printed on recycled paper
Printed by the US. Environmental Protection
Agency for the Chesapeake Bay Program
About This Report
The Chesapeake Bay 2005 Health and Restoration Assessment is
presented in two parts. In Part One: Ecosystem Health, the most cur-
rent data available are used to provide a scientifically based assess-
ment of the health of the Bay. In Part Two: Restoration Efforts, key
restoration actions are measured against long-term restoration goals.
Part One: Ecosystem Health uses monitoring data gathered by Bay
Program partners to assess the overall health of the Bay ecosystem
over a one-year period. These annual assessments of water quality
parameters are affected by freshwater flow to the Bay. High flow
years contribute to decreasing water clarity and potentially affect
dissolved oxygen and chlorophyll. A three-year assessment that helps
to remove the impacts of annual weather-driven events (such as
drought and high flow years) is depicted on pages 13 and 14. Where
possible, data are compared to existing goals that measure progress
toward restoring a healthy Bay. By presenting data in this manner,
watershed residents can better understand the health of the Bay rela-
tive to what is needed for a balanced ecosystem.
In the Water Quality and Habitats sections of this report, individual
parameters are averaged together to provide an overall health assess-
ment for each section. In the Fish and Shellfish section, however,
independent data about individual species cannot be combined to
provide an overall assessment of the health of Bay fisheries. As eco-
system-based goals are defined in the future, we will compare annual
data to population targets needed for a restored Bay system.
For more information about the data, methodology and restora-
tion goals discussed in this report, please visit www.chesapeakebay.
net/assess/methods.
This report represents a change in the way the Chesapeake Bay Pro-
gram annually reports on the health and restoration of the Bay and
its tidal rivers. The Bay Program encourages the public to review
and comment on this report through May 31, 2006. To submit com-
ments, please visit www.chesapeakebay.net/assess. The Bay Program
has also scheduled this report for an independent scientific review
later this year. The partnership will incorporate recommendations
from both reviews into future efforts.
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The Chesapeake Bay Watershed
The Chesapeake Bay is an estuary - a place of tran-
sition between the land and the sea, where incom-
ing fresh water mixes with salty ocean water. The
Chesapeake Bay is a productive ecosystem and is
the largest estuary in North America, home to more
than 3,700 species of plants and animals.
The Bay's watershed covers an enormous 64,000-
square-mile area that includes parts of six states
- Delaware, Maryland, New York, Pennsylvania,
Virginia and West Virginia - and all of the District
of Columbia. Billions of gallons of water flow each
day through thousands of streams and rivers that
eventually empty into the Bay.
While the size of its watershed contributes to its
productivity, it also helps contribute to its woes.
With a watershed land to Bay water volume ratio
seven times that of any other major estuary in the
world, the Bay must process runoff from a large
amount of land with a relatively small body of water.
A healthy Bay requires balancing the needs of the
region's people and economy with the needs of the
Bay for clean waters and ample habitat for aquatic
life. The goal of Bay restoration is to restore this
balance by reducing pollution, protecting critical
habitat and ensuring sustainable populations of fish
and shellfish.
NEW YORK
JD.C.1
WEST
VIRGINIA
VIRGINIA
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V~---'' • ' "-:
Health Assessment Summary
The Chesapeake Bay is at a crossroads, with its future health still at stake.
For 20 years, restoration efforts have been underway to reverse the decline
of the Bay's health, but the cumulative impact of centuries of population
growth (currently 16 million) and landscape changes has taken its toll.
Water Quality
Most of the Bay's waters are degraded. Each summer, a large expanse of
its waters does not hold enough oxygen to support striped bass (rockfish),
crabs and oysters. Algal blooms fed by nutrient pollution block sunlight
from reaching the underwater bay grasses needed to support aquatic life.
Sediment from urban development and agricultural lands is carried into
the Bay, clouding its waters and covering critical oyster reef habitat. Cur-
rently, about one-third of Bay water quality goals are being met.
Habitats and Lower Food Web
The Bay's critical habitats and food webs are at risk. Nutrient and sedi-
ment runoff have harmed bay grasses and bottom habitat. Excessive algae
growth has pushed the Bay food web out of balance. A large portion of
the Bay's wetlands has been lost to development. Currently, the Bay's
habitats and lower food web are at about a third of desired levels.
Fish and Shellfish
Many of the Bay's fish and shellfish populations are below historic levels.
The number of adult blue crabs is below the long-term average for the
seventh straight year and oyster populations are at or near historic lows.
American Shad are recovering slowly, while other species like striped bass
(rockfish) show mixed signals. Current rockfish populations exceed resto-
ration goals, but approximately 60 to 70 percent are infected by a disease
called mycobacteriosis. Researchers are currently working to understand
the extent and severity of the disease and the extent to which environmen-
tal conditions in the Bay influence it. As ecosystem-based goals are not
yet developed for fish and shellfish species, data are not averaged in this
section this year.
One- and Three-Year Water Quality Assessments
The evaluation of Bay water quality described in the above summary and
on pages 5-7 provides an overview of conditions on a year-by-year basis.
This analysis highlights the annual variation experienced by the Bay and
its aquatic life.
Information presented on pages 13 and 14 details how the restoration
effort stands in relation to meeting its ultimate goal of "restoring Bay
water quality." This determination will be made by comparing monitored
conditions to state water quality standards. To help ensure conditions are
not just a result of one year of "good" weather, data collected over the past
three years is used to determine compliance with those standards.
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Summary: 2005 Bay Health Assessment
Priority Areas
Percent of Goal Achieved
0 10 20 30 40 50 60 70 80 90 100%
Water Quality
Dissolved Oxygen
Clarity
Chlorophyll a
Chemical Contaminants
Bay Grasses
Phytoplankton
Bottom Habitat
i
Tidal Wetlands
Not quantified this year
Data and Methods: www.chesapeakebay.net/assess/methods
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High quality waters are the foundation
of a healthy Chesapeake Bay. To sup-
port a vibrant Bay ecosystem, waters
must become clearer, oxygen levels
higher, and the amount of algae and
chemical contaminants in its waters
must be reduced.
Goals in this section are based on cri-
teria designed to protect aquatic life
in the Bay.
Oxygen Needs of Key Species
Striped Bass: 5-6
American Shad: 5
Water Quality
Throughout 2005, many of the region's envi-
ronmental and economic stories focused on the
Chesapeake Bay. From an ecological perspec-
tive, one of the most important stories high-
lighted low oxygen levels observed in the Bay
and some of its rivers during the summer.
North End
of Bay
Susquehanna
Dissolved Oxygen
Summer 2005 saw near-record
low dissolved oxygen condi-
tions in many parts of the
Bay. In many areas, levels were
insufficient to support resident
aquatic life. As the map to the
right shows, levels were lowest
along the mid-channel areas of
the Bay and its rivers, especially
in the mid-Bay area. This low
dissolved oxygen area
lasted longer and
covered a larger area • 10.0 mg/i
than in most years. __
7 "*" 7.5mg/l
39
Low oxygen condi-
tions are the result of
excess pollution com-
bining with weather
conditions and the
bottom contour of
the Bay. In 2005,
heavier than normal
spring rains washed large amounts of
pollution into the Bay. Once there, the
S.0mg/1
2.5mg/l
Omg/l
Center Transect
(See Side
View Below)
South End
of Bay
Side View of Dissolved Oxygen Levels - Summer 2005
North End
of Bay
o
South End
of Bay
Depth
so J
39
38° 37°
Data and Methodsiwww.chesapeakebay.net/assess/methods
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summer's light winds were unable
to mix the Bay's waters, and large-
scale low oxygen areas persisted in
bottom waters. Higher than average
water temperatures further reduced
the water's ability to retain suffi-
cient oxygen for aquatic life.
As shown in the side view of the
Bay, waters near the surface tend
to hold more oxygen than waters
closer to the bottom. The red areas
in the image highlight the anoxic
- or oxygen deprived - waters that
occupied the Bay's depths during
much of the summer.
Like terrestrial animals, the Bay's
fish and shellfish need oxygen to
survive. During summer months,
a large volume of the Bay's waters
does not hold enough oxygen to
support them. Throughout sum-
mer 2005, scientists estimate about
24 percent of the Bay met dissolved
oxygen restoration goals designed
to protect resident aquatic life.
Over time, large-scale reductions
in the amount of nutrients flowing
into the Bay will help improve low
oxygen conditions.
Mid-Channel Water Clarity
Dissolved Oxygen
PerontofSay
Mttttng OukMtms
100-
90
80
70 -
60
50 -
40
30 -
20 -
10 -
Goal
24%
of Goal Achieved
1990
199S
2000
Data and Methods: www.chesapeakebay.n
Mid-Channel Water Clarity
p«i«*nt of Station*
Matting Guidrtlnn
45%
of Goal Achieved
1985
1990
1995
2000
2005
Data weighted by respective salinity zone.
Data and Methods: www.chesapeakebay.net/asses5/niethods
Clear waters are indicative of a healthier Bay, with
acceptable levels of nitrogen, phosphorus, sedi-
ments and algae in the water column.
Water clarity is most important in shallow areas
close to shore. Unfortunately, systematic monitor-
ing of shallow water clarity has been underway for
only the past few years and there are not yet suffi-
cient data to provide a baywide assessment. In this
report, water clarity in deeper, mid-channel, areas
is used to indicate general conditions and trends.
Based on the mid-channel monitoring network,
water clarity in 2005 was better than in the previ-
ous two years, but the long-term trend is downward.
About 45 percent of approximately 150 monitoring
stations reported acceptable levels of water clarity.
Assessed by measuring how far light can penetrate
into the water column, improved water clarity will
come from reduced amounts of nutrients and
sediment flowing into the Bay and its rivers. Water
clarity will always fluctuate annually, as it is greatly
impacted by weather events, however, reduced nutri-
ent loadings, abundant bay grasses and healthy Bay
life will help improve annual conditions.
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Chlorophyll a
Scientists measure the amount of
chlorophyll a (the green pigment
in plants) in the Bay's waters to
assess the amount of algae present.
The Bay needs the right amount
of microscopic algae to maintain a
balanced food web. Too much algae
can cause large-scale algal blooms
that block sunlight from reach-
ing bay grasses, reducing available
habitat to Bay life. Lower algal levels
promote better water quality, more
available habitat and fewer harmful
bloom effects.
Chlorophyll a
Paront of Bay
Meeting GuMillrn*
100-
41%
of Goal Achieved
80-
TO-
60
50
40-
10-
Goal
1985
1990
1995
2000
2005
In 2005, scientists estimate that
about 41 percent of the Bay's waters had acceptable
chlorophyll a concentrations. Bay scientists attri-
bute the poor conditions to the pulse of nutrients
washed into the Bay during the spring's heavy rains.
Chemical Contaminants
Chemical contaminants are not only found
throughout the Bay's waters but also in the sedi-
ment and in tissues of fish. When they reach cer-
tain levels, they can impact aquatic life and human
health. One way scientists assess levels of contami-
nation is to examine a group of harmful chemical
pollutants called PCBs in tissues of white perch - a
resident species of fish found in the Bay's rivers.
Since perch tend to stay in the same river for their
entire life, they serve as an excellent measure of
chemical contaminants for that river.
Surveys suggest that in only 38 percent of the Bay's
tidal rivers, white perch PCB levels are low enough
for unrestricted human consumption. Generally
fish from rivers on the Bay's western shore have
higher concentrations than those on the eastern
shore, and rivers further north have higher concen-
trations than those in the south.
Scientists are also concerned about mercury levels
in the Bay's waters. Mercury contamination will be
Data and Methods: www.chesapeakebay.net/assesVmethods
addressed in future versions of this report.
2005 River Flow and Pollutant Loads
Reaching the Bay
Annual Chesapeake Bay water quality conditions
are largely determined by a combination of the
amount of pollution deposited on the land and
the amount of water flowing into the Bay. As the
volume of water flowing into the Bay - or river flow
- increases, its potential to carry increased pollut-
ants increases as well.
Total river flow to the Bay in 2005 was very close
to the long - term average. Pollutant loads were
close to average as well. However, their combined
impact on the Bay may have been greater in 2005
as a higher than usual portion of the annual load
occurred in the critical spring time period.
Precipitation doesn't just increase river flows by
washing directly off the land. Some water seeps into
the land, carrying nutrients into groundwater. It
can take years for these waters and their associated
pollutants to slowly travel through underground
systems until they reach the streams that drain into
the Bay. Some of this year's load actually came from
pollution sources that are decades old.
7
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Scientists calculate annual pollutant loads to the
Bay through a combination of monitored water sam-
ples and modeled information. Whenever possible,
scientists measure pollution levels in water samples
from the rivers and pipes that flow into the Bay.
Model generated estimates are used where monitor-
ing is not practical. By capturing water samples at
the point where large rivers meet the Bay, scientists
can calculate pollution loads from 78 percent of the
watershed. For the remaining area, model gener-
ated estimates are used. This unique combination
of monitoring and modeling data allows scientists to
provide the most complete accounting of the amount
of pollution reaching the Bay.
Provisional estimates indicate that approximately
370 million pounds of nitrogen and 26.1 million
pounds of phosphorus reached the Bay during
the 2005 water year (October 2004 to September
2005). These amounts are well above the restora-
tion target of 175 million pounds of nitrogen and
12.8 million pounds of phosphorus. Additional
pollution-fighting measures are being put in place
throughout the watershed to reduce annual pollu-
tion loads in the future.
River Flow and Nitrogen Loads Reaching Chesapeake Bay
River How |
Millions of
Pounds of Nitrogen
800 H
• Modeled Data
• Monitored Data
600-
400-
AwiragiLoad
200
1990 1995
2005 data provisional.
Billions of
Gallons Of Flow
25
2000
2005
Data and Methods: www.chesapeaketoay.net/assess/nwthods
4 '
1
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Life in the Bay needs high-quality food
and habitat to thrive. From the clams
and worms that live within the Bay's
bottom, to the rockfish that prow! its
open waters, to the juvenile fish and
crabs darting among underwater
grasses and wetlands, habitat sup-
ports the Bay's aquatic life. When
healthy habitat is supported by a
balanced food web, healthy aquatic
communities can flourish. As both of
these areas improve, the ecosystem's
potential to support larger and more
diverse populations of aquatic life ex-
pands as well.
Habitats and Lower Food Web
Bay Grasses
Aside from the water itself, underwater bay grasses are one of the
most important habitats in the Chesapeake Bay. As their health
is closely related to the quality of local waters, grasses serve as an
excellent barometer for the overall health of the estuary. Bay grass
abundance has a profound effect on the Bay and its aquatic life, as it
provides critical habitat to key species such as striped bass and blue
crabs while improving the clarity of local waters.
Bay Grass Abundance
Percvnt of Zon*
92%
of Goal Achieved
29%
of Goal Achieved
42%
of Goal Achieved
2005 data 'a preliminary. Data and Methods: www.chesapeakebay.net/assessymeihods
The most recent baywide data from 2004 show bay grasses covering
72,935 acres - or about 39 percent of the 185,000 - acre baywide res-
toration goal. Increases in the upper Bay from improved water clarity
have led the baywide resurgence of underwater grasses, while acreage
has decreased in the middle and lower Bay over the past decade.
Scientists' preliminary acreage estimate for the lower Bay in 2005 is
19,219 acres, a 10 percent increase from the same areas mapped in
2004. Soon after the 2005 survey was conducted, many lower Bay
grass beds unexpectedly lost their leaves and died. Scientists will
assess how this will impact future bay grass abundance in the 2006
survey.
As water clarity improves from nutrient and sediment pollution
reductions, bay grass acreage should continue to expand.
Bottom Habitat
The bottom of the Bay is home to bacteria, clams, worms and other
creatures that serve as a key food source for higher levels of aquatic
life, such as white perch, spot, croaker and crabs.
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The health of the Bay's bottom
dwelling - or benthic - communi-
ties is greatly reduced when pol-
lution levels increase and oxygen
levels drop. Benthic habitats serve
as a good indicator of long-term
environmental conditions, as their
inhabitants are long-lived, have lim-
ited mobility and their responses to
stress are well documented.
In 2005, about 41 percent of the
Bay's benthic habitat was consid-
ered healthy as measured by the
composite Benthic Index of Biotic
integrity. This decline is likely due
to persistent low dissolved oxygen
levels during the summer. Reduced
amounts of nutrients, sediment
and chemical contaminants flowing
into the Bay will help these bottom
dwelling communities improve.
Phytoplankton
Phytoplankton - microscopic plants
commonly called algae - are an
excellent indicator of the health of
the Bay's surface waters, as they are
especially sensitive to changes in nu-
trient pollution and water clarity.
Bottom Habitat (Benthic Index of Biotic Integrity)
GoalAcnlmd
100-
1
41%
of Goal Achieved
A Accounting Begins
90
SO
TO-
CO
50 -
40
SO-
20 -
10 -
Goal
1985
1990
2000
2005
Data and Methods: www.ehesapeakebay.net/assess/metnods
Phytoplankton (Index of Biotic Integrity)
Percent of B«y
MMtlng Ouldtlln*
100-
ao
70 -
eo -
50 -
40
0 "i
Goal
9% «85
of Goal Achieved
1990
1995
2000
2005
Data and Methods: www.chesapeakebay.net/asses5/methods
Phytoplankton form the base of the food web.
While increased populations provide more food to
organisms further up the food web, too much or
the wrong type of algae can harm the overall health
of the Bay. In some cases, harmful algal blooms can
impact human health.
Scientists assess microscopic algal community
health with a Phytoplankton Index of Biotic In-
tegrity. Data from Spring 2005 show that about 9
percent of the Bay's phytoplankton communities
were considered healthy.
Tidal Wetlands
Wetlands link land to the water. In both tidal and
non-tidal parts of the Bay, they serve as critical habi-
tat to terrestrial and aquatic life, and act as natural
filters by removing pollutants from water before it
can reach local streams and the Bay.
Measuring the health and acreage of wetlands
throughout the watershed is a difficult and expen-
sive task. Regional scientists are currently develop-
ing methods to assess wetland function and track
changes in acreage on a watershed level. For more
information about wetland improvement efforts, see
page 6 of Part Tu/o: Restoration Efforts.
10
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The long-term health and sustainabil-
ity of the Bay's fish and shellfish is
critical to restoring ecosystem health.
Ample aquatic habitat, clean water
and well-managed fisheries are key
components to restoring abundant
fish and shellfish populations to the
Bay.
Scientists and natural resource man-
agers are working to develop ecosys-
tem based fisheries management
strategies which take into account nu-
merous factors when setting harvest
targets, including the species' role in
the food web and other water quality,
habitat and climatic considerations. As
these strategies are further developed
and ecosystem goals are defined, the
Program will compare annual data to
population targets for a balanced Bay
system.
Fish and Shellfish
Blue Crab
The number of mature female Chesapeake Bay blue crabs, or
spawning stock, remains below the long-term average (a restoration
goal has not yet been established). Although some indices have
Blue Crab Abundance
1970
1975
1980
1985
1990
1995
2000
2005
Data and Methods:www.chesapeakebay.net/as5ess/methods
Striped Bass Abundance (Spawning Female Biomass)
t of
Goal Achieved
100%
of Goal Achieved
1982 1985
1990
1995
2000
2005
Data and Methodsiwww.chesapeakebay.net/assess/methods
shown improvements in recent years, the
Chesapeake Bay Stock Assessment Com-
mittee warned that the overall health of
the blue crab population warrants con-
tinued concern. Fisheries managers in
Maryland, Virginia and on the Potomac
River are being advised to retain protec-
tive blue crab harvest restrictions in order
to ensure the long-term sustainability of
the blue crab population.
Striped Bass
The striped bass - or rockfish - popu-
lation has dramatically increased over
the past decade in the Chesapeake Bay.
Scientists attribute this increase to a late 1980s fishing moratorium
and responsible fisheries management since the lifting of the fish-
ing ban. In 1995, populations had increased to the point where the
species was considered restored. While biomass remains high, data
gathered over the past three years show a slight decline.
Scientists are concerned over the species' health, as a large percent-
age of striped bass suffer from poor nutrition and 60 to 70 percent
of the population is infected with the disease mycobacteriosis. Re-
search is underway to better understand the disease's impact on
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stocks. The current status of Bay
striped bass - high abundance
but uncertain health - illustrates
the need for an ecosystem-based
fisheries management approach in
Chesapeake Bay. For more informa-
tion, see page 7 of Part Two: Restora-
tion Efforts.
Oysters
For more than a century, oysters
constituted one of the Bay's most
valuable commercial fisheries.
Over-harvesting, pollution and
diseases such as Dermo and MSX
have caused a severe decline in their
numbers throughout the Chesa-
peake. Scientists estimate that the
population of native oysters in the
Chesapeake Bay in 2004 is about 7
percent of current restoration goals.
American Shad
The introduction of hatchery raised
fish, a moratorium on shad fishing,
the removal of dams, and instal-
lation of fish passages on key Bay
tributaries have helped to increase the number of
shad returning to the Bay.
One of the ways scientists currently estimate spawn-
ing shad populations is by counting the number of
fish annually lifted over Conowingo Dam near the
mouth of the Susquehanna River. Annual estimates
have increased from several hundred per year in
the early 1980s to an average 101,140 per year in
2003-2005. In 2005, 68,926 American shad were
counted as they passed over the dam. In spite of
their increased abundance, the Susquehanna River
population is far below the long-term restoration
goal of two million fish.
Assessing annual baywide spawning populations is
difficult as each river stock is unique. To provide
better baywide estimates, scientists are developing
Native Oyster Abundance (Biomass)
Percen
Goal Ach
90 -
TO -
60 -
SO -
40 -
30 -
20 •
1 «:
•.»- o-
7% '
of Goal Achieved
A Accounting Begins
Of
DTOd
1 ••
985 1990 ^995 2000 2005 2010
3oal based on ten - fold biomass increase from 1 994 baseline.
3ata and Methods: www.chesapeakebay.net/assess/methods
Shad Returning to the Susquehanna River
Percent of
Goal Achieved
100-
90-
60
50 -
40
30-
20-
10 -
Goal
3%
of Goal Achieved
1980
1985
1990
1995
2000
2005
Based on Susquehanna River Restoration goal of 2 million shad.
Data and Methods: www.chesapeakebay.net/assesi/methods
new monitoring methods to estimate populations
in other key Bay tributaries including the James and
Potomac rivers.
Atlantic Menhaden
Scientists currently do not produce Chesapeake Bay
specific population estimates of menhaden. Estimates
are made on an Atlantic Coast wide basis. Popula-
tions along the Atlantic Coast appear to be healthy,
but scientists are concerned with a possible "localized
depletion" in the Chesapeake Bay, one of the species'
key nursery areas. The number of juvenile menhaden
has been declining in recent years, with current re-
cruitment levels being five to ten times lower than the
mid-1980s. Since menhaden are an important forage
species in the Bay food web, a number of studies are
underway to assess their status in the Bay.
12
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With about three-quarters of the nu-
trient pollution entering the Chesa-
peake Bay through surface runoff and
groundwater, the annual health of the
Bay is largely driven by the amount of
pollution deposited on the landscape
coupled with weather conditions
across its vast watershed. Rains, es-
pecially heavy downpours, wash pollu-
tion off the land and into local streams
and eventually the Bay.
In years where there is less rainfall
and lower river flow, the Bay's tidal
waters will likely be clearer, hold more
oxygen and generally be much health-
ier. Conversely, high rainfall years will
generally lead to poorer water quality
conditions.
The challenge to Bay restoration lead-
ers is to reduce the amount of pollu-
tion flowing into the Bay in all years.
By restoring the land's ability to natu-
rally filter water and putting in place
pollution-fighting practices across the
entire watershed, restoration leaders
hope to improve Bay health and re-
duce annual variability, :
Assessing the Health of the Bay Over Multiple
Three Year Bay Water Quality Assessment
When assessing the Bay's tidal water quality, federal and state regula-
tors examine conditions over the most recent three years to help
remove annual weather-driven fluctuations. To meet water quality
restoration goals, monitoring data from the Bay and its tidal tribu-
taries must attain a set of criteria measured over those three years.
Dissolved Oxygen
State water quality standards have been developed to meet the dis-
solved oxygen needs of the Bay's aquatic life. The standards vary
with depth, season and duration of exposure. Generally speaking,
oxygen rich shallow waters are most essential in the spring during
spawning season. Slightly lower dissolved oxygen levels are accept-
able at other times of the year and in deeper waters. Water quality
data gathered between 2003 and 2005 indicate that about 29 per-
cent of the Bay's waters met dissolved oxygen standards during the
summer months.
Shallow Water Clarity
Based on bay grass acreage data from 2002 to 2004, 27 percent
of the Bay's segments met water clarity standards. Scientists have
observed diverging water clarity trends when analyzing data collected
from shallow water areas and from mid-channel monitoring stations.
Improving trends in bay grass acreage in shallow waters has been
observed, while mid-channel clarity data show reduced clarity over
time. (See annual mid-channel water clarity information on page 4.)
Chlorophyll a
For this year's report, chlorophyll a guidance from the James River is
used to assess this key water quality measure. Scientists are currently
working with state and federal regulators to develop science-based
chlorophyll standards for adoption into the Bay states' water quality
standards. Using the James River guidance, data from 2003 to 2005
indicate that conditions at 48 percent of the Bay's waters met accept-
able algae levels as measured by chlorophyll a.
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Three Year Dissolved Oxygen Standards Attainment
GMlAchlovM
100-
I
29%
of Goal Achieved
90-
ao
70-
60-
50 -
40
SO -
20-
10 -
- 0
• Goal
Year of Assessment
1987 1990
1995
2000
2005
2010
Data represent 3 year period (data year and preceding 2 yean)
Data and Methods: www.chesapeakebay.net/assess/methods
Three Year SAV-Based Clarity Standards Attainment
_
Percent
GoilAcM
100-
90 -
80 -
70 -
60 -
50 -
40 -
30 '
H~- 1;:
27% i
of Goal Achieved
of
eved
_/
Year of Assessment
986 1990 1995 2000 2005 2010
3ata represent 3 year period (data year and preceding 2 years). Attainment based on
xrcent of segments achieving darity standards based on single-best-year SAVacreage.
3ata and Methods: wwwjchesapeakebay.net/assess/methods
Three Year Chlorophyll a Guidance Achievement
Goul Achieved
100
48%
of Goal Achieved
1987 1990
1995
2000
2005
2010
Data represent 3 year period (data year and preceding 2 years)
Data and Methods: www.chesapeakebay.net/as5ess/methods
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Improving the Health of the Bay
The Chesapeake Bay's ecosystem
health remains substantially degrad-
ed. Water quality dips dangerously
low during some critical periods an-
nually, and essential habitats face
constant pressure. The restoration's
goal of "abundant, diverse popula-
tions of living resources" will require
improved fisheries management as
well as improvements in water qual-
ity and other habitat.
For more than twenty years, water-
shed residents have worked with gov-
ernment leaders to put in place pro-
grams to restore and protect the Bay
and its watershed. While those ef-
forts have been numerous and wide-
spread, they have not been enough.
to yield large-scale improvements in
water quality and habitat.
For more detailed information about
the work being done to restore Bay
ecosystem health, please see Part
Two: Restoration Efforts.
Image: tn April 2005, near record rains washed large
amounts of sediment into the Bay, resulting in large
sediment plumes in the Bay and many of its rivers. The ( ,
mainstem plume began at the head of the Bay and car-S *
ried some 80 miles south to Chesapeake Beach, Md.,1
reducing water clarity for weeks in the upper Bay.j
Image courtesy of MODIS Rapid Response Project at ~_
NASA/GSFC.
This report was developed by the Chesapeake Bay Program partnership to help inform watershed residents about the health of the Bay and efforts to restore it. Staff from a large number of state
and federal agencies, academic institutions and non-governmental organizations contributed data and interpretation to the report, including The Alliance for the Chesapeake Bay, Chesapeake
Bay Commission, Del. Dept. of Natural Resources and Environmental Control, DC Dept. of Health. Interstate Commission on the Potomac River Basin, N.Y, Dept. of Environmental Conservation,!'
National Oceanic and Atmospheric Administration, Md. Dept. of Agriculture, Md. Oept. of the Environment, Md. Dept. of Natural Resources, National Park Service, Old Dominion University, Pa, Dept,1'
' -' f-'^yation and Natural Resources, Pa, Dept. of Environmental Protection, Pa. Fish and Boat Commission, Susquehanna River Basin Commission, University of Md. Center for Environmental,
•ersity of Md. College Park, U.S. Army Corps of Engineers, USDA Natural Resource Conservation Service, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, U.S. .
U.S. Geological Survey. Va. Dept. of Environmental Quality, Va, Dept. of Conservation and Recreation, Va. Dept. of Game and Inland Fisheries, Va. Institute of Marine Science, Va.j
$Versar, W.Va. Dept. of Agriculture and the W.Va. Dept. of Environmental Protection. For a full list of contributing partners, visit http://www.chesapeakebay.net/baypartners.htm. JB
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