PRODUCTION 



These dangers must include potential 

 alteration of the environment as the 

 result of the heat added as a by- 

 product of generating electricity by 

 nuclear means. The whole concept 

 of the ocean's capacity to produce 

 food for man and the technological 

 capacity to use it is a subject of cur- 

 rent discussion. The impact of loss 

 of these resources or inability to de- 



velop their potential must be consid- 

 ered in evaluating future food sources. 



We cannot assume that pollution 

 problems will be resolved in time to 

 maintain present biological produc- 

 tion. Indeed, man's multi-purpose 

 needs to use the water environment 

 for transport, to exploit its mineral 

 potential, to develop it for real estate 



and industrial pur] to use 



it to dispense his waste products in- 

 crease the likelihood that we may 

 ultimately degrade the general pro- 

 ductivity of the sea. In this respect, 

 the criterion of sublethal level of tol- 

 erance is irrelevant if the accretion 

 of pollutants continues. Time, in this 

 instance, does not possess the infinite 

 quality usually ascribed to it. 



Some Scientific Problems Associated With Aquatic Mammals 



The following list of problems as- 

 sociated with aquatic mammals is 

 made up mostly of broad, general 

 problems. There are also many spe- 

 cialized problems, such as diving 

 physiology or the ecology of specific 

 parasites. 



Pollution Hazards 



Effect of Pesticides, Petroleum, and 

 Other Pollutants on Marine Mam- 

 mals — The flow of pesticides and 

 other chemical pollutants into the 

 ocean is concentrated in marine mam- 

 mals since they are at the top of the 

 food chain. (See Figure VIII— 8) It is 

 known that chlorinated hydrocarbons 

 are in the tissues of marine mammals 

 in every part of the world. The effect 

 of the chemicals is not at all known. 

 A possibility exists that the apparent 

 high rate of premature births in Cali- 

 fornia sea-lions is related to pollutants. 

 Little is known about the effect of 

 petroleum on marine mammals except 

 that it reduces the insulating capa- 

 bility of fur. This is lethal for sea 

 otters and fur seals in the marine 

 environment and for the furred fresh- 

 water mammals such as otter, mink, 

 muskrat, and beaver. 



Pollution of the types mentioned is 

 continually increasing. Unless the 

 hazards are understood, marine mam- 

 mal populations can be reduced or 

 lost before the potential effects of the 

 hazard are realized. A variety of 

 sampling experiments and tests with 

 captive animals can be devised to 

 show the effects of the pollutants. 



Conservation and Management 

 of Stocks 



Management of World Whale 

 Stocks to Preserve the Species and 



Restore a Resource — Short-term eco- 

 nomic gain has been the overriding 

 consideration in the exploitation of 

 the large species of whales. Pursuit 

 of this end has resulted in depletion 



Figure VIII— 8 — THE FATE AND DISTRIBUTION OF MARINE POLLUTANTS 



POLLUTANT 



Diluted and 

 dispersed by 



MARINE 

 ENVIRONMENT 



Turbulent 

 mixing 



Ocean 

 currents 



Uptake by 

 fish 



Transported 

 by 



Ocean 

 currents 



Migrating 

 organisms 



Concentrated 

 by 



Biological 

 processes 



Chemical and 

 physical processes 



Uptake by 

 phytoplankton 



Uptake by 

 seaweeds 



Adsorption 



Precipitation 



Invertebrate 



benthos 



Zooplankton 



z 



Fish and mammals 



Ion 

 exchange 



Accumulation 

 on the bottom 



The diagram shows the various processes that determine the fate and distribution 

 of pollutants in the marine environment. Under favorable conditions, the pollutants 

 are diluted, dispersed, and transported by turbulent mixing, ocean currents, and 

 migrating organisms. Unfortunately, the oceans are not mixed thoroughly and 

 high concentrations of pollutants exist in local areas. In addition, there are 

 biological, chemical, and physical processes taking place that concentrate 

 pollutants and lead the pollution back to man. 



245 



