39 



of the total harvest of seafood taken by American fishermen comes from estuaries 

 or the waters over the continental shelf. About two-thirds of that harvest con- 

 sists of six'cies whose existence depends upon the estuarine zone or which must 

 pass through the estuary enroute to their spawning grounds. The salmon v/hich 

 used to abound in our Northeast rivers are excluded from practically all of 

 them today, either because of the construction of dams or because of the pollu- 

 tion of the water itself. Many productive shellfish ground ■ have been closed 

 because of pollution, and our inshore fisheries resources are less abundant, which 

 is due, in jart at least, to overfishing. 



Today, there ai*e increasing demands upon the coastal zone for many of man's 

 activities. Navigation, disposal of pollutants, and fisheries resources remain 

 important, but the recreational demands of our population are increasing dra- 

 matically. In the coastal waters the.se traditional users are in conflict with many 

 of the amenities and more i>ers()nal uses which our population rightfully feels 

 should he maintained for future benefits. 



By hindsight we can evaluate what man has done in the past, but we do not 

 understand well enough the ways in which the marine ecosystem works to 

 predict the results of new or proposed engineering developments. I think that 

 it is clear that technology exists which would prevent or ameliorate the impact 

 of marine pollution upon the environment, but we must apply this technology 

 and be willing to pay the cost of correcting past errors and of preserving our 

 marine environment for the benefit of future generations. 



It is worth emphasizing that large parts of our coastal zone are still relatively 

 unmodified by man's activities and that severe deterioration has been localized 

 in areas of large ix>pulation densities. It is imperative that the natural areas 

 be preserved in their unmodified state even as we strive to improve the quality 

 of areas which have been degraded. The Coastal Zone Workshop in Woods Hole 

 la.st year discussed these problems at great length (The Water's Edge. Ketchura, 

 1972). The Coastal Zone Management Act of 1972 recognized the need for estu- 

 arine sanctuaries which should be preserved in a natural state to permit con- 

 tinuing research on the ecological relationshiixs within the area. Additional 

 recognition of the need has also been provided in the Marine Protection, Research 

 and Sanctuaries Act of 1972. Such sanctuaries would preserve and protect the 

 genetic stocks of plants and animals essential for the i>eritetuation of the 

 marine ecosystem. 



POLLUTANT CHARACTERISTICS 



There are three characteristics of each pollutant which must be understood 

 before one can evaluate the possible impact or hazard of its release to the 

 environment. The.se are (a) the quantities produced which may reach the en- 

 vironment, (b) the toxicity of the ix)llutant to marine organisms and to man 

 if it will reach him in his seafood, and (c) the persistence of the pollutant in 

 the environment. Our knowledge is incomplete; sometimes with regard to all 

 three of these essential characteristics of pollution. For example, production 

 statistics are frecpiently considered to be proprietary information which industry 

 will not make public. This makes it difficult or impossible to make a "materials 

 balance" analysis of the flow of the substance through the environment, an 

 analysis which is essential if we are to evaluate the relative impacts of different 

 pollutants. It is obAious that a highly toxic pollutant which reaches the en- 

 vironment in very small quantities may be far less important than a less toxic 

 material which is released in massive quantitie.s. 



General categDries of materials may be cited as examples of the range to be 

 expected among these characteristics. At one extreme are the heavy metals which 

 are produced in large quantities, are toxir- at low concentrations and do not 

 degrade biologically or chemically, even though they may be trapped in the 

 sediments and thus removed from the water column reducing their impact. Once 

 added to the marine environment, however, the.v are there forever. 



Various .synthetic organic compounds, particularly the chlorinated hydro- 

 carbons such as DDT and the polychlorinated biphenyls have also been produced 

 in large quantities and are now found even in the water and organisms of the 

 oi)en ocean. Tliese compounds are not produced naturally and organisms have 



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