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Dr. White. They addressed the question of what is the optimum 

 sustainable population. They came to the conclusion the lowest was 

 50 to 60 percent. If we had anv stock which was below 50 percent of 

 the original level, which we did not, everybody would agree that it 

 was depleted by the terms of the act. 



Now we have a stock that is 54 percent of its original level. That 

 falls somewhere between the estimates of 50 to 70 percent of the 

 lower limit of the optimum sustainable population. The question 

 therefore arises as to how you make the judgment as to whether 

 that stock is or is not depleted. 



There are scientists that will take the view that it is not depleted. 

 There are others who will take the view that it is depleted. 



In our judgment, as to whether it was depleted or not, we were 

 persuaded by three rather cogent factors. One was the view of the 

 Marine Mammal Commission, which was established by statute to 

 provide oversight on these matters. And we have a letter from them 

 which indicates that they believe the stock of Eastern Spinner por- 

 poises is depleted. 



Further, our own statistical analysis indicates that there is about 

 a 60-percent chance that the eastern spinner porpoise is depleted. 

 We were then faced with the question of whether a 60-percent chance 

 of its being depleted warranted our declaration of eastern spinner 

 as being depleted. 



We came down on the side of saying it is. It was a close call, but 

 we did not see any alternative after also considering the views of 

 the Marine Mammal Commission, but to come down on the side of 

 its being depleted in terms of the act. 



To get to the question of the biological depletion, everybody agrees 

 that you could take as many as 6,600 per year of the eastern spinner 

 porpoise population and still have the virtual certainty that the 

 stock of that porpoise would continue to increase. That is a separate 

 statement, however. 



Mr. Leggett. You could take that number and have a virtual cer- 

 tainty that a depleted species is increasing? 



Dr. White. That this species is increasing. 



Mr. Leggett. OK, Dr. White. 



Dr. White. But we were faced by the requirements of the law 

 that say once a species is declared depleted, we cannot allow any 

 take of* that particular species. That is the dilemma we are in. We 

 know, from a biological point of view, that you can allow a take and 

 still have that population increase. On the other hand we are con- 

 strained by the law and the interpretation of the courts that we can- 

 not allow that take. It is a dilemma. 



We fully appreciate the economic hardship it is causing to indus- 

 try. That is why I said we must look at some changes in the act that 

 would permit us to reduce the porpoise mortality which, I believe, 

 we can do and still allow the industry to fish. 



Mr. Forsythe. Mr. Chairman? 



Mr. Leggett. Mr. Forsythe. 



Mr. Forsythe. Dr. White, there is also doubt whether we can de- 

 fine the optimum sustainable population for particular species if you 

 take the whole ecosystem approach. 



