SEALS AND FISHERIES 325 



counting the pups surviving.) Then you have to have accurate knowledge of 

 the hfe-table for the species under your consideration. It has been estimated 

 that bulls become mature at eight and a half years: I believe that the true 

 figure is higher than that. I deprecate most strongly the use of figures of the 

 degree of unreliability of most of those which we have had today. 



E. B. Worthington: Although the picture is based on 'guesstimates* it 

 seems to be one of interaction between a population with a steady upward 

 trend — the grey seal — and another with extreme fluctuations — salmon. 



Rae's paper clearly contains some sweeping conclusions, but I feel that it 

 is most important that we examine it in full, with its supporting data, before 

 agreeing with or rejecting these conclusions. 



In spite of the inadequacy of the data and divergent conclusions that have 

 been drawn, some interim decisions must be made about seal populations 

 and salmon fisheries. It is evident that the pohcy must be based on considera- 

 tions of the whole populations involved, and not on the isolated study of 

 local aggregations of them. 



F. Raw : Surely it is possible to see some figures of the losses (from 

 nets) of salmon destroyed and damaged, the former loss being estimated, if 

 necessary. 



K. A. Pyehnch: One has also to take into account the damage to nets, 

 not just to salmon: such net damage may release unharmed fish. 



J. B. Cragg: Are the data pubhshed? 



J. DE B. Stansfeld: The figure of the actual catches of salmon are 

 supplied by the fisheries to the Scottish Home Department, but they are not 

 published for ten years. There is no reason why percentage figures should 

 not be given. Any company would be prepared to give these and to indicate 

 the percentage of damaged fish in the catch. 



I would emphasize that in Scotland we are suffering considerably from 

 this damage. We are not asking for the extermination of seal: only for a 

 reasonable — and quick — measure of control for an extremely expensive 

 predator. 



