EPA - 903/9-76-001
AQUATIC PLANT DIE-OFFS IN
CHESAPEAKE BAY
Relationship to light penetration
and or herbicide pollution
VOLUME I
JULY 1976
FIRST PROGRESS REPORT
(for June, 1976)
SMITHSONIAN INSTITUTION
CHESAPEAKE BAY CENTER FOR ENVIRONMENTAL STUDIES
EDGEWATER, MARYLAND 21037

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EPA - 903/9-76-001
AQUATIC PLANT DIE-OFFS IN
CHESAPEAKE BAY
Relationship to light penetration
and or herbicide pollution
VOLUME I
By
David L. Correll
Tung-Lin Wu
Jack W. Pierce
Smithsonian Institution
Chesapeiake Bay Center for Environmental Studies
Route 4, Box 622
Edgewater, Maryland 21037
Project Officer
Len Mangiaracina
Chesapeake Bay Program
Environmental Protection Agency
6th and Walnut Streets
Philadelphia, Pennsylvania 19106
JULY 1976
FIRST PROGRESS REPORT
(for June 1976)

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3.
The work upon which this
publication is based was
performed pursuant to P.O.
WD-6-99-0766-J
with the Environmental
Protection Agency.

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4.
INTRODUCTION
In the last decade a spectacular die-off of all species of submerged
aquatic plants has occurred all over the Chesapeake. Now only small
'pockets' of these plants may be found in the bay. This is also a phe-
nomena observed recently on other east coast estuaries. The suspected
results include reduced forage for wintering waterfowl, increased shore-
line erosion, and loss of habitat for commercial fisheries species.
The two most popular hypotheses to explain this die-off are in-
creased turbidity due to erosion and phytoplankton blooms and/or in-
creased herbicide pollution levels. This research project was designed
to gather preliminary data to test whether either of these hypotheses is
correct. A recent conference on No-Till agriculture:(held in January
1976 at Hershey, Pennsylvania) pointed out that Maryland leads the nation
in the use of agricultural herbicides, and that the levels of use are
rising rapidly. Chemical and Engineering News, May 19, 1975, gave data
on a national level for the use of herbicides on corn and soybeans,
Maryland's principal crops. In 1974, 400 and 280 millions of dollars
worth respectively of herbicides were applied in the U.S. to corn and
soybean crops and this use rate is predicted to rise to 520 and 480
millions of dollars worth, respectively by 1980. Thus, it is apparent
that studies of the relative effects of various herbicides in estuaries
are urgently needed, if we are to determine which one(s) may be used
without serious damage to aquatic environments

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5.
OBJECTIVES
General
To conduct a preliminary research study to test whether higher aquatic
plant die-offs are the result of increased turbidity and/or of herbicide
pollution from agriculture at the time of year when these factors should
be most critical for the plants.
Specific
1.	To measure the concentration distribution patterns of herbicides
in the spring following -agricultural herbicide applications, in two western
shore subestuaries of Chesapeake Bay, one with a high and one with a low
proportion of agriculture on its watershed.
2.	To measure the concentration distribution patterns of herbicides
in an area of shallows of the open bay, formerly noted for dense higher
aquatic plant beds and in an eastern shore subestuary representative of
agricultural watersheds in that region.
3.	To measure suspended particulate concentrations and submerged
higher aquatic plant distributions in these areas.
4.	To determine whether a good correlation exists between higher
aquatic plant distributions and turbidity or herbicide levels in the Ches-
apeake.

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6.
SAMPLING STATUS REPORT
Collection of samples at five stations (28, 28.4, 29, 30.2, and
31.5) in the Rhode River was carried on April 13/April 21 (for baseline
data), on May 25, and on June 22. On June 10 samples were collected at
six stations (91-96) on the Severn River. On June 16 and 17 samples
were collected at eight stations (71-78) on the Choptank River. On
June 18 samples were collected at four stations (81-84) near the Pop-
lar Islands. Stations were always scattered evenly along the axis of
each tidal river from near the upper extent of tidal action to the mouth.
Samples taken on station included submerged aquatic plants, turbidity
of surface waters, suspended particulates in surface waters, filtered
surface water, and bottom sediments. Suspended particulate and bottom
sediment samples are being analyzed for partical size distribution,
mineralogy, and percent organics. Filtered water, suspended particulates
and bottom sediments are being analyzed for the herbicides atrazine,
alachlor, linuron,.and simazine. Submerged higher aquatic plants were
sorted by species, counted, dried, and weighed. In all cases phyto-
plankton chlorophyll a levels were determined in surface waters along
transects between stations.

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7.
METHODS
Submerged higher aquatic plants:
A common steel garden rake is used to collect plants by scrapping the
surface of the bottom sediments in random paths in areas of 0.6 to 1.2 meters
depth. Sampling stations are selected in areas of shallows relatively pro-
tected from wave action. A total area of bottom of from 10 to 100 square
meters per station is sampled, depending upon plant abundance. Samples of
plants from each station are sorted by species, counted, dried to constant
weight at 60° C in an oven and weighed. On site visual observations are also
recorded of presence or absence of plants.
Phytoplankton Chlorophyll a concentrations:
Between stations the boat was operated at an even speed and surface
waters were pumped continuously from a depth of 0.5m through a flow-thru
door (110-880A) on a Turner model 111 flurometer. The flurometer had a
F4T4-BL blue excitation lamp, a Corning 5-60 excitation filter, a Corning
2-64 emission filter and a red sensitive photomultiplier tube (R-136).
The signal was recorded on a strip chart. A sample of known volume was
taken at a marked time position on the chart, filtered through a Mi Hi pore
HA filter, and the filter was dissolved in 90% acetone saturated with
MgC03 and stored in the dark. The acetone extract was then analyzed for
chlorophyll a by the method of Loftus, M.E., and Carpenter, J.H.(J. Marine
Research 29:319-338;1971). The average invivo fluorometer response was
then determined by integration of the transect recording and the concen-
tration of chlorophylla was determined by multiplying times the ug invitro
chlorophylla a per invivo response unit.
Turbidity:
A Hach, model 2100A, turbidimeter was used to measure the turbidity of

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8.
samples in the field. It was calibrated, in Jackson units, with sealed
standards before each measurement. Three samples of surface waters were
analyzed at each station.
Suspended particulate characterization:
Surface water samples were filtered through prewashed and weighed
Millipore HA filters. Weight gain was used to assay for total particu-
lates. Mineral particulates were determined after firing organic matter
present in the sample. Size fractions and mineralogy were determined as
described by Carroll (Clay Minerals: A Guide to Their X-Ray Identification,
Geo!. Soc. Amer. Sp. Paper 126, 80pp.; 1970).
Bottom sediment characterization:
At each station 3 Pflueger cores were taken unless the bottom was too
hard in which case 3 Ekman Dredge samples were taken. These samples were
analyzed for percent organics, mineralogy and mineral particle size dis-
tribution. In the case of cores these parameters were measured as vertical
profiles.
Herbicide sampling:
At each station 151 of surface waters are taken and 50g Ca CI^ are added.
The sample is allowed to stand overnight and is then filtered through a Gil-
man, type A, glass fibre filter. The filter is then treated with anhydrous
sodium sulfate and extracted with benzene and methylene dichloride. The
filtrate is extracted with benzene and then with methylene dichloride.
Sediment cores (3) were taken at each station with a Pflueger corer.In cases
of hard bottom conditions, a set of three Ekman dredge samples were taken.
These sediment samples were stored on ice until they could be segmented (cores).
Subsamples of lOg weight were then mixed with lOg. anhydrous sodium sulfate

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9.
and extracted with benzene and methylene dichloride.
Herbicide analyses:
Organic solvent extracts of samples were concentrated in a Kuderna-
Danish Evaporator in a water bath. The sample was then chromatographed
on a column of alumina, activity grade V, prewashed with petroleum ether
and topped with anhydrous sodium sulfate. Samples were eluted with
hexane and then hexane/benzene (50:50 by volume) and were concentrated.
Samples are then analyzed on a gas chromatograph equipped with an electron
capture detector.

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10.
RESULTS
This report is an initial progress statement. Since laboratory anal-
yses, have not progressed very far and data processing is still under way
no final conclusions or detailed results can be reported at this time. As
noted in the following milestone chart field sampling is on schedule and
nearly complete. Collections are still scheduled in the Rhode River for
July and August. Laboratory characterization of suspended particulate
and bottom sediments and herbicide analyses of all types are just beginning.
Turbidity and chlorophyll data is ready for processing on the completed
cruises. Aquatic plant population data is ready for processing for the
completed cruises. No significant equipment or field problems have oc-
curred.
Some preliminary observations can be reported. Of the stations sampled,
submerged higher aquatic plants were most abundant in the Rhode River, where
they were common at all stations. Plants appeared to be totally absent on
the Choptank River above Cambridge and at some stations at the Poplar Islands
and on the Severn River. Where plants occurred, many were apparently healthy
and had flowered. Most of the plants collected were of the following species:
Rupia maritima, Zannichellia pallustris, Potamogeton perfoliatus, and Pota-
mogeton pectinatus. Turbidities were lowest on the Poplar Islands, the
Severn River and the lower Choptank River and highest on the upper Choptank
River. Phytoplankton chlorophyll a values were highest on the Severn, es-
pecially in Round Bay where higher aquatic plants were also most abundant
on the Severn River. Chlorophyll levels were also high in the Rhode River
and low in the Choptank River and near the Poplar Islands.

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11
MILESTONE CHART
	Activity	Task	Status	
Intensive field sampling	1,2,3	near completion
Laboratory analysis of samples 1,2,3	initiated
Processing of field and	4	initiated
laboratory data
Analysis of all data	4	not yet initiated

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12.
CHAPTER 2
FOBMAT
SCIENTIFIC AND
TECHNICAL PUBLICATIONS
TECHNICAL RcPORT DATA
(Please rend Inttrucrioftt ca the reverse btfore completing)
1. REPORT NO. 3.
EPA - 903/9-76-001
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SU&TITLE
AQUATIC PLANT DIE-OFFS IN CHESAPEAKE BAY
telationship^fojight penetration and or
5. REPORT DATS
Julv 1976(date nf prpn)
9. PERFORMING ORGANIZATION COOS ' '
^axjfefeftiide pol 1 uti oh.
David L. Correll, Tung-Lin Wu, Jack w. Pier
8. PERFORMING ORGANIZATION REPORT NO.
ce
9. PERFORMING ORGANIZATION NAMi ANO ADORfiSS
Smithsonian Institution
Chesapeake Bay Center for Environmental Stuc
It.. 4, Rnx ft??, FHnpwaf pr, Maryland ?1D?7
10. PROGRAM ELEMSNT NO.
11. CONTRACT/GRANT NO.
"WD-6-99-0766-J
12. SPONSORING AGENCY NAM8 Atfb AODRBS9 ' w
Chesapeake Bay Program
Environmental Protection Agency
>th & Walnut Streets, Philadelphia, Pa.19106
13. TVPE OP REPORT ANO PERIOD COVERED
Proaress Renort-.lune 19;
14. SP0NSORINO AGEfrCY COOB
IS. SUPPLEMENTARY NOTES
16. ABSTRACT
Samples and data have been collected to begin the determination
of whether the distribution and species composition of submerged
higher aquatic plants in Chesapeake Bay are related to herbicide
concentrations and/or the turbidity and phytoplankton concentra-
tions. The Rhode,1Severn and Choptank Rivers and the waters near
the Poplar Islands were sampled.
17. KEY WORDS AND DOCUMENT ANALYSIS
•>. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Crimp
Aquatic Plants
Turbidity
Phytoplankton
Herbicides
Chesapeake
Bay
Program
Chesapeake
Bay
SB. DISTRIBUTION STATEMENT
Release unlimited
19. SECURITY CLASS (Tha Report)
21. NO. OF PAGES
12
20. SECURITY CLASS (Thitpoje}
22. PRICE
6
EPA Form 22200 (9*73)
IN 3
5-1-'.-74
Figure 2-2. Technical Report Data I'agc
(Part 1 of 2)
CHAP 2

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