500 REPORT ON TRAWLING AND OTHER INVESTIGATIONS 



size and higher vahie. The marking experiments show that at least 

 41 per cent, of the marketable plaice marked in Teignmouth Bay were 

 subsequently caught by the fishermen, viz. 31 per cent, during the 

 first year, and 10 per cent, during the second. 



On the other hand, the closure of Start Bay appears to deprive the 

 small trawlers of a serious proportion of the large plaice which they 

 would otherwise secure. Only 23| per cent, of the marked plaice from 

 Start Bay were recovered, viz. 21^ per cent, in the first year and 2 per 

 cent, in the second. The difference between the percentages in the two 

 experiments appears to indicate that about 10 per cent, of the large 

 plaice in Start Bay annually migrate outside the area of the Mumble 

 Bees altogether. It is impossible at present to say whether this migra- 

 tion materially' affects the upkeep of the trawling grounds in the 

 Channel, to which it undoubtedly contributes ; but, regarding the 

 matter merely from the standpoint of the Brixham fishery, it appears 

 fairly certain that the closure of Start Bay altogether deprives the 

 small trawlers of a considerable number of large plaice, against the 

 capture of which no biological objections can be urged. 



(8) In view of the facts ascertained by these investigations, and 

 liaving regard to the permanent maintenance of the fishery, it would 

 appear to be highly inadvisable to rescind the regulation which pro- 

 hibits trawling in Teignmouth Bay and Torbay. On the other hand 

 tliere are no biological reasons against the reopening of Start Bay, 

 either as a whole or in its northern part alone, as suggested by Mr. 

 Holt in his previous report. 



In this connection it cannot be overlooked that the natural migra- 

 tions of the fishes determine to a large extent the areas in a particular 

 district which it is profitable or unprofitable for the trawlers to work 

 over. There is no doubt that during the autumn months the plaice are 

 concentrated in the bays, especially in Start Bay. At this season of 

 the year the trawlers are limited by the closure of the bays to the soles 

 and whiting on the offshore grounds (cf. Table A). 



