432 



3. The collection of more comprehensive catch and effort statistics for all 

 fisheries where unavailable at present. 



Peter B. Best, chairman; J. Bannister, S. Brovi^n, W. Evans, E. Mit- 

 chell, S. Ohsumi, H. Omura, U. Rice, W. van Utrecht, members. 



Report of the Workinff Group on Biometrics and Management 



The group concludes as follows : 



1. The northern and southern seas are among the most biologically produc- 

 tive regions on Earth. In these regions, maoro-planktonic animals in most .strik- 

 ing abundance are the euphausids and copepods — the diet of the baleen whales. 

 Although direct harvesting by man of these zooplankton resources, especially of 

 euphausids, has been proposed and some research is in progress to this end, 

 practical and economic techniques have not yet been devised. Harvesting of 

 whales is, at present, by far the most effective way of tapping these resources. 

 Even if and when practical techniques are devised, they could supplement rather 

 than replace the whale harvest since the optimum whale stock sizes (i.e. those 

 giving maximum sustainable yields) are at about half the unexploited levels, 

 and we would expect there to be a large harvestable zooplankton surplus in these 

 circumstances. 



2. The herds of the great whales, which are our common heritage, could at 

 optimum stock levels contribute significantly to human needs for protein. We 

 therefore concur with a policy for whale management which will insure that 

 no stock is reduced below its optimum level or, when this has already happened, 

 exploitation is restricted to permit the stock to recover to its optimum. 



3. The history of the past centuries has been one of successive over-exploitation 

 of many of the major whale species. Bowhead, right, gray, blue, humpback, and 

 some stocks of fin whales have been depleted to well below their optimum levels. 



The present scientific evidence is sufficiently good to provide guidance in gen- 

 eral terms for the management of most stocks of large whales. Action has been 

 taken by the International Whaling Commission to rebuild stocks of the most 

 depleted species. Reduction of fin and sei whale stocks that had been occur- 

 ring at a very rapid rate has been slowed or stopped. But this is not good enough 

 since no deliberate action is yet being taken to rebuild the very important Ant- 

 arctic fin whale stock. The more conservative estimates suggest that this stock, 

 and some other stocks of fin, sei, and sperm whales, are still being depleted, al- 

 though rather slowly. No action has yet been taken to prevent the over-expoita- 

 tion of the remaining unexploited stocks of cetaceans, particularly the Antarctic 

 minke whale. 



The group aflSrmed that it is not enough to seek protection for a species only 

 after its numbers have been .so reduced as to threaten its existence. This mini-, 

 mum action is not resoui*ce management. Restraint should be exercised early 

 enough that the species remains sufficiently abundant to fulfill its role in the 

 ecosystem. It seems reasonable to assume that a species held at the level of 

 maximum sustainable yield is still a major element in the ecosystem and that 

 the policy of harvesting at maximum sustainable yield is therefore not at variance 

 with considerations of ecology. 



Existence of means of harvesting and of markets for the products must, in 

 the absence of regulation, be seen as an implicit danger to the wellbeing of a 

 species or stock. Thus, we recognize as a general principle of re.source manage- 

 ment that controls must evolve as new areas and species are opened to exploita- 

 tion and as major technological innovations appear. In the past when industries 

 have been allowed to expand without restraint, economic considerations have 

 made it difiicult or impossible for the industry to abide by the necessary reduc- 

 tions. Application of regulations after a period of over-exploitation has usually 

 meant a period of painful readjustment to a more rational pattern. Increasingly 

 rapid rates of exploitation might otherwise be presumed to lead to depletion 

 before conclusive scientific evidence on the optimum stock size could be obtained 

 and regulation .secured. A possible remedy to protect newly exploited species 

 might be to set an arbitrarily low quota which can be raised as data provided 

 by capture indicate how high su.stainable yields can be set. Specifically, it is rec- 

 ommended that conservative catch quotas should be set forthwith for the Ant- 

 arctic minke whale stocks. Better scientific information would permit a more 

 responsible attitude on these matters to be adopted. 



As .scientists, we feel that the burden of proof that any given rate of harvesting 

 will not endanger a stock must rest with those who stand to benefit from such 

 harvesting. The industry should accept the judgment of a competent group of 



