million of dissolved oxygen is essential to the completion of the life 

 cycle of the economically important hard shell clam. 



Projects at the Environmental Research Laboratory at Gulf Breeze, 

 Fla. are directed to determining the toxicity of pesticides. This work 

 includes evaluating the impact of pesticides and polychlorinated 

 biphenyls on marine ecosystems and determining the pathways and 

 mechanisms of pesticide degradation in the marine environment. 

 The Laboratory also assays the effects of new pesticides on marine 

 organisms. The Gulf Breeze Laboratory is currently studying 

 methoxychlor, malathion, and mirex. Methoxychlor and malathion 

 are two pesticides that are now being substituted for DDT. Mirex is 

 an organochloride used extensively in the Southeastern United 

 States to treat fire ants. 



Other agencies supporting environmental quality research are the 

 AEG, NOAA, (through its Sea Grant Program), DOI, and the 

 Smithsonian Institution. The AEG supports a program directed to 

 tracing the movement of radioactive elements throughout the oceans 

 and determining the pathways by which radioactivity may progress 

 through the marine food chain and eventually return to man. In one 

 of its projects, the AEG, in cooperation with the National Marine 

 Fisheries Service is conducting basic studies relative to food web 

 dynamics in oceanic, coastal, and estuarine environments. A major 

 effort is underway to describe the structure and function of coastal 

 plain estuaries near Beaufort, N. G. This research involves studies of 

 the transfer of energy at all levels of the food web as well as studies 

 on the physiological responses of estuarine organisms to thermal 

 stress and the cycling of trace metals within these ecosystems. The 

 movement of radioelements through the marine environment, the 

 means and rates of return of radioactivity to man through marine 

 food webs, and other ecological process are of vital concern to all 

 mankind. 



Another major effort in food chain research is being conducted at 

 the Scripps Institution of Oceanography and consists of a 

 multidisciplinary investigation directed toward understanding the 

 transfer of energy in planktonic food webs in the North Pacific 

 Ocean. Additional food web research is being conducted in such 

 diverse marine environments as the Gulf of Mexico, the Ghesapeake 

 Bay, and coastal waters of Washington and Oregon. 



Researchers supported by the National Sea Grant Program are 

 monitoring the effects of thermal and radioactive discharges from 

 nuclear power plants to assess their effects on marine life, primarily 

 on commercial fisheries. Wastewater, dredge spoils, and solid 

 wastes are targets of other studies on pollutants that threaten to 

 degrade the marine environment. Scientists supported by Sea Grant 

 are also studying the physical, chemical, and environmental 



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