Vol. 16—1962 - NorthEastern Weed Science Society

FIELDOBSERVATIONS UPONESTUARINE ANIMALS EXPOSED TO2,4-D l
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G. Francis Beaven, Charles K. Rawls, Gordon~. Beckett
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ABS'l"RACT
Oysters, crabs, clams and fish were held near the center and outside
of one.acre tidewater plots of Hlri9phYllumfPl~tum L. during
and after treatment with the butoX1.ethanol-ester'o,~.4:D at several
specified rates. Mortality of the caged animals in 'reated plots and
in controls was observed for five weeks. Examinationof native bottom
or~isms in the plots was madeb, hFdraulic dredge aadby grabs with
a Petersen dredge. Results indicate that applieatiOl1 at rates as
high as 120 lbs. acid equivalent per acre are not dl.ect1y lethal
to the caged animals. In one instance an anaerobic,eondition developed
that was lethal to both caged and native animals. Whennormal
aerobic conditions are maintained,tr.eatments of 3OU,. liE/Aresulted
in no mortality to the native macro-fauna observed and did not
kill the valuable native plants.' Groupsof animals:eiposed to the
above treatnient are being analyzed fo~ herbicide red¢ues. I '
INTRODUCTION j.
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The ChesapeakeBiological Laboratory of the University of MarylandNatural
Resources Institute, in cooperation with the PatuxeatWildlife Research
Center, the MarylandDepartmentof Ga.m$'andInland Fish. and the Virginia
Institute of Marine Science, is engagedin a joint research programupon the
varied aspects of invasion of the Chesapeakearea by ~sian watermilfoil
(Myriophyllumspicatum L.). This paper,deals with preliminary observations
of the effects upon certain native aquatic organisms that result from milfo11
control by 2,4-D in tidal estuaries.!
Acknowledgment and sincere appreciation is expresst4 for the help given'
to this phase of the study by personnel of the above agencies, by the Taft
Sanitary Engineering Laboratory, by the manycooperat1!18',shOreownersand
marina operators in the areas where the experiments we:rliconducted,and by
Mr. Robert Wakefield, a student of Antioch College who'bred in the field
workduring the spring and early summer.
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Contribution No. 192 of the Nat~ral Resources Iattitute of the Uni~
versity of Maryland, ChesapeakeEiological LabQtAtory,Solomons,Md.
Senior Biologist, Shellfish Investigations, ChesapeakeBiological
Laboratory.
Biologist II, Aquatic weedstudies, ChesapeakeBiological Laboratory.
Biologist I, Aquatic weedstudies (nowgraduate .tudent at OklahomaState
University).
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