218 



Anadromous fish 



Landings of anadromous fish, particularly those of economic im- 

 portance such as the salmon and shad, have declined in numbers, while 

 retail markets have generally shown a steady improvement. 



The diminution of the continental salmon fishery provides a classic 

 example of the damage inflicted on fisheries by biophysical modifica- 

 tion. As dam-building, lumberins:, and other kinds of man's activities 

 increased, the once-abundant salmon catches declined. The Atlantic 

 salmon has almost completely disappeared from the east coast. On the 

 west coast, reduction in the quality and quantity of freshwater, sedi- 

 mentation in spawning areas, pollution of the transitional zones in 

 estuaries, and heavy fishing pressure by both sport and commercial 

 fishermen have combined to reduce the once-flourishing salmon 

 industry. 



Most of the domestic catch now comes from salmon dependent on 

 the streams, rivers and estuaries of Alaska, since that State is for the 

 most part free of the physical and biological modifications made by 

 man in the other Pacific coast States. Growth of logging, oil, natural 

 ^as, and hydroelectric activities may alter this situation drastically 

 m coming decades. Even without these modifications, which have little- 

 known effects on the possible sustained yield of Alaskan salmon, this 

 fishery faces serious economic and institutional problems. Fishing 

 pressure is rising significantly because of increased numbers of fisher- 

 men and improved harvesting teclmology, while catch per fisherman 

 has declined greatly. Increases in market price sustained this odd 

 circumstance, as figure IV.4.13 shows. 



Future prospects 



Examples of the historical decline and projected pressures on the 

 domestic commercial fishery could be multiplied many times. The 

 market demand for fishery products is growing and is projected to 

 rise sharply in the near future, but the amount of that market which 

 will be supplied by imports is not yet clear. 



It is the conclusion of many experts in the field that a harsh choice 

 must be made in the near future : either the management of the Na- 

 tion's estuarine resources will be substantially strengthened, institu- 

 tional constraints relieved, and the trend toward degradation of the 

 estuarine environment stemmed, or the supply of commercially val- 

 uable finfish and shellfish to meet rising demands will diminish. 



Mariculture, the manipulation of the estuarine or marine environ- 

 ment to increase production of commercial species, is often cited as a 

 method to overcome the depletion of natural stocks and fill increasing 

 market demands for fish products. The ability of artificial culture to 

 significantly increase yields has been proven in countries such as Japan 

 where shrimp, oyster, and certain finfish are raised on a profitable 

 basis. However, the economic use of mariculture is in its infancy in 

 the United States. Although the ultimate impact of aquaculture prac- 

 tices would appear great, increasing yields from five to as much as 

 20 times, the present economic and social climate would seem to indi- 

 cate that the impact of mariculture will be relatively slight in im- 

 mediate future decades. When other ancillary values are added, it 

 would appear that proper management of the natural estuarine en- 



