GREY SEALS AS COMPETITORS WITH MAN FOR SALMON 321 

 Proportion of this food that was salmon and sea-trout = 



-?-^ X 111,020 lb 

 100 



= 21,800 lb (9,875 kg). 



COMMERCIAL CATCHES 



This information is based on: (a) confidential information from certain 

 salmon fishing companies; (h) published accounts; and (c) estimates based on 

 the situation and size of the fishery where the catch is not precisely known. 



Catches of sea-trout and grilse (salmon that have spent just over one year 

 in the sea) are included in the total. Where the catch is expressed in sterling, 

 the weight has been calculated using the average price wholesale of salmon 

 in 1957 as given by the Scottish Home Department Annual Report (1957). 



On this basis the total catch for coastal stations, estuarine fisheries of the 

 Tweed and the rod catch of the River Tweed was in 1957 approximately 

 731,000 lb (331,580 kg). 



CONCLUSION 



During the 1957 salmon fishing season, man removed 731,000 lb of salmon 

 and sea-trout. A very imprecise calculation suggests that immature grey 

 seals and young bulls removed 23,000 lb of salmon and sea-trout from the 

 same area, or about 3 per cent of the total catch (range, 0-3 to 30 per cent). 

 In addition, there is an unknown amount eaten by an unknown number of 

 mature seals. Clearly we do not yet know enough to draw conclusions 

 about grey seals as competitors with man for free-living salmon even on 

 this rather well-documented section of the British coast. However, a solution 

 to the problem, while difficult, is by no means impossible. 



The more serious gaps in our knowledge which are necessary for this kind 

 of study can be listed as follows : 

 (i) The annual mortahty of the various age-groups. 



(2) The exact age at which breeding commences in each sex. 



(3) The distribution of immature animals. 



(4) The age-groups frequenting the salmon nets. 



(5) A food study that takes into account the limitations of stomach analysis 

 and the difficulties of sampling in the field. 



Happily, some of these are already under investigation and we may 

 expect others to be tackled now that Mr E. A. Smith has been appointed by 

 the Development Commission and based at the Nature Conservancy, 

 Edinburgh, to study the problem of seals and fisheries. 



