PART VIII — AQUATIC ECOSYSTEMS 



community exploitation. The concept 

 of optimizing yields from single 

 species, although argumentative, is 

 established in principle. But models 

 are not yet available on which to base 

 an aggregate species-management ra- 

 tionale, and we haven't the foggiest 

 idea of the possibilities of exploiting 

 marine fishes on a range-management 

 concept. Finally, although there is a 

 good body of information relating to 

 feeding patterns of fish, the tropho- 

 dynamics, or energetics, of food-chain 

 systems are still poorly understood 

 and are, to a degree, rooted in 

 mythology. 



Recent Additions to Scientific 

 Knowledge — Considerable new in- 

 formation on the distribution, mag- 

 nitudes, and community aspects of 

 demersal and benthic fishery re- 

 sources has been compiled, particu- 

 larly during the past decade for cer- 

 tain areas of the North Pacific. 



Important among these are the 

 recent Soviet works (four volumes) 

 which provide life-history data and 

 information on the dynamic aspects 

 of the fish and shellfish resources of 

 the Bering Sea and Gulf of Alaska. 

 These volumes also include new con- 

 tributions as related to benthic com- 

 munities, some new descriptive ocean- 

 ography, and an attempt to establish 

 environmental-resource relationships. 

 In addition, the recent contribution to 

 the understanding of the Kuroshio 

 Current should provide a basis on 

 which to examine its influence on the 

 adjacent fishery resources. 



The contribution of oceanography 

 to fisheries in the past decade lies 

 largely in describing the environment. 

 This contribution must be tempered, 

 however, by the fact that the de- 

 scriptive features to date are too gross 

 to deal effectively with some prob- 

 lems, particularly those relating to 

 survival of eggs, larvae, and young 

 of species that are commercially 

 utilized. Furthermore, the availability 

 of theoretical formulation, including 

 mathematical modeling, exceeds our 



empirical capacity to evaluate model- 

 ing forecasts. 



Needed Scientific Advances 



The major scientific controversies 

 concerning the North Pacific fisheries 

 relate to (a) the total possible contri- 

 butions of its elements to the food 

 stream, (b) the importance of mari- 

 culture vis-a-vis developing more effi- 

 cient systems to utilize wild stocks, 

 and (c) the character of relation- 

 ships between adult populations and 

 recruitment. 



Fisheries Management — Among 

 the priorities for scientific advance is 

 the need to develop management 

 concepts and techniques for timely 

 implementation of management. Fish- 

 eries management has been and con- 

 tinues to be largely remedial in 

 character. We need to cope with the 

 problem of pulse-fishing activities, 

 examine it as a theoretical basis for 

 utilizing ocean resources, and find 

 mechanisms that will allow us to 

 forecast trends sufficiently in advance 

 of their manifestation to implement 

 effective management. The concept 

 must cope with managing aggregates 

 as well as single species. 



The most critical scientific needs 

 as regards management and use of 

 North Pacific fisheries relate to de- 

 riving the nature of the stock recruit- 

 ment relationship, the reaction of 

 multi-species fisheries, the prediction 

 of environmental factors that bring 

 about year-class fluctuations or other- 

 wise influence stock recruitment rela- 

 tionships, and a clear, fundamental 

 understanding of the potential impact 

 of persistent pesticides and other for- 

 eign substances on the productivity 

 of the total ocean food chain, as well 

 as the potential contamination of the 

 food sources. 



A number of fishery resources in 

 the North Pacific appear to have 

 been overexploited, resulting in loss 

 of food potentials. This seems to 

 have been the product of failure to 



find an effective means of implement- 

 ing management decisions and the 

 inability of existing monitoring sys- 

 tems to detect important changes in 

 sufficient time to react in a respon- 

 sive manner. 



Resource Assessment — In addi- 

 tion to the problems of managing 

 exploited resources, there is a real 

 need to evolve the fishing strategy 

 that will allow us to use the full 

 potential in the ocean. This may re- 

 quire considerable information on the 

 behavior patterns of species (a) in the 

 natural state, (b) in response to exist- 

 ing fishing gears, and (c) in response 

 to physical or chemical stimuli that 

 might be used for herding or aggre- 

 gating marine life. 



One of the shortcomings is tech- 

 nological instrumentation to carry out 

 resource-assessment activities. Most 

 of the classical methods are not really 

 effective for the task. One of the real 

 weaknesses of the data is that they 

 do not provide contemporary infor- 

 mation. The greatest success is likely 

 to come from the development of 

 sonar assessment techniques. Inte- 

 gration of returned echoes, in con- 

 junction with a means of identifying 

 the target, could provide a reliable 

 method for obtaining stock data over 

 wide areas within reasonable costs. 

 Acoustic holography offers some 

 promise of fish identification detected 

 at relatively close ranges. 



Impact of Pollution — Perhaps the 

 greatest urgency relates to the area 

 of the multiple demands on the 

 ocean's environment. The hazards of 

 pollution in the North Pacific and the 

 potential contamination of the food 

 resources therein are major questions 

 that must be answered in the next 

 decade. We are only beginning to 

 consider the possible implication of 

 man's multi-purpose needs on the 

 ocean's environment. The whole field 

 of pollution — ranging from persist- 

 ent pesticides and other industrial 

 chemicals to oil pollution and the 

 like — obviously represents a danger 

 which is not adequately understood. 



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