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CHLORINATED HYDROCARBONS AND PLASTICS 



One group of globally significant pollutants is totally foreign to 

 the naturally occurring atmosphere and ocean — the manmade chemi- 

 cals used as pesticides and industrial solvents and insulating fluids, 

 PCB's. These compounds are extremely i^ersistent . They may be carried 

 by winds either clinging to particles or as vapors, and are accumulated 

 and concentrated by organisms. 



In other words, we have a persistent group of substances with known 

 biological effects that can be dispersed throughout the entire atmos- 

 phere. We know that these materials are biologically concentrated and 

 widely distributed throughout the marine food chain, including heavy 

 concentrations in certain fish-eating birds. 



Recent limitations on the use of these materials in the United States 

 should assist in attacking this problem, although they continue to be 

 used widely in many other nations. In the meantime, as with oil, we 

 must track their distribution and learn more about their effects. 

 NOAA's LaJolla Laboratory is attempting to gain an understanding 

 of the distribution of chlorinated hydrocarbons in the California cur- 

 rent and eastern tropical Pacific regions, the characteristics of sources 

 of these pollutants, and the processes influencing their transport in 

 the atmosphere and ocean. 



We are presently cooperating with EPA to monitor pesticide 

 residues in estuaries. We are also studying the effect of DDT on re- 

 production of anchovies and whether this DDT is transmitted to the 

 eggs of this fish during exposure to DDT. 



Plastics are also emerging as ubiquitous reminders of man's impact 

 on world environment. NOAA's MARMAP program recently re- 

 ported the widespread occurrence of plastic in the North Atlantic. 

 Styrofoam cups litter much of the North Atlantic Ocean. "\'Miile the 

 biological effects of such plastic debris upon fish are not known, this 

 is an area calling for continued scrutiny. 



TOXIC METALS 



Toxic metals are contaminants of global interest. They enter the 

 ocean from many sources. Once there, tliey are indestructible. Our 

 marine contaminants program is yielding some basic information con- 

 cerning distribution of these materials in marine fishes. We are study- 

 ing such things as the effects of heavy metals on all stages of mollusks, 

 crustaceans and fish; the responses of membranes and cells to pol- 

 lutants; and the movement of heavy metals from prey to predators 

 and back into the environment. 



I would like to talk now about some of the effects on human food 

 resources, of great concern to all of us. 



Thus far I have discussed these pollutants in forms of their effects 

 on the ecosystem. Equally important questions center around their 

 effects on human health basically on the extent to which these materials 

 are contaminatins: food i-esources and making them unsafe for human 

 consumption. 



Pollution has had a heavy impact on the Nation's shellfish resources. 

 About 30 percent of the Nation's presently harvestable oyster and clam 

 beds are closed to harvesting because of contamination with human 

 wastes. 



