OCEANIC PRODUCTION 



Figure VII 1—7 — DISTRIBUTION OF THE WORLD'S FISHERIES 



INDIAN 

 OCEAN 



^] COASTAL AREAS— About 50% ol Global Commercial Harvest 

 s.^> UPWELLING AREAS— About 50% ot Global Commercial Harvest 

 _| Less than 1% of Global Commercial Harvest 



INDIAN 



OCEAN 



The map shows the fisheries of the world today. Fish production in the future 

 will depend on the responses of this system to exploitation and on the oppor- 

 tunities that may derive from a better understanding of the system. One critical 

 factor is the total fish production of the oceans, which has recently been estimated 

 to be only four times greater than the 1968 catch, for corresponding species. 

 Another is the vital role played in estuaries and along coastlines, where pollution 

 threatens the nurseries of many commercial species. A third is the role of 

 upwelling. Weather is important to the success of fishing, and further improve- 

 ments in local weather forecasting await a better understanding of larger-scale 

 meteorological phenomena. Altogether, the systems of air, water, and life are 

 intimately interwoven in the production of fishery yields. 



dominance, and succession in the 

 ocean communities are the subject of 

 considerable rhetoric, most of which 

 is rather fanciful. Hence, we have 

 not been able to get a firm grasp of 

 the relationship between parental 

 stock and subsequent recruitment, 

 nor have we been able to interpret 

 the implications of environmental 

 contamination (degradation) on early 

 life-history phases of marine fauna. 



Knowledge of the environment that 

 various groups of commercially ex- 

 ploited fish and shellfish inhabit has 

 improved considerably in the past 

 decade, although it is descriptive in 

 character. We can probably state 

 that we now have a fairly firm esti- 

 mate of mortality coefficients (mor- 

 tality, growth rates, etc.) for repre- 

 sentative species that are subject to 

 commercial fishing. It is possible that 



we can generalize and make fairly 

 good estimates for species for which 

 these coefficients have not been estab- 

 lished. Similarly, we are starting to 

 get a fix on the response of single- 

 species fisheries to the mortality re- 

 sulting from man's exploitation. 



Limitations — By contrast, how- 

 ever, the existing models are inade- 

 quate to cope with multi-species or 



243 



