PRODUCTIVITY OF THE SEA FISHERIES 323 



Firth of Clyde were selected for experiment. Some of these areas were closed 

 to commercial fishing and others were left open, and periodic trawls were made 

 by the Scottish Fishery Board steamer Garland in order to detect what 

 differences (if any) would be the result of the closure. Prof. Mcintosh was 

 himself the scientific member of the Board (for the constitution of that body 

 provided for such a member as well as a scientific stafi), and he, if anyone, 

 is familiar with the results of these famous experiments. Their results are 

 tabulated in the book under notice, but I doubt if any reader will be able to 

 digest them, and in any case there is little doubt that they were inconclusive. 

 Far more searching investigation was necessary. 



At any rate, the conclusion that Prof. Mcintosh makes is that there was 

 no evidence that trawUng could deplete or impoverish a fishing ground. The 

 question is partly a natural history one and partly one that is to be discussed 

 in the light of very exhaustive statistical data. In so far as it is a question of 

 natural history no one is better able to judge than our author, with his un- 

 rivalled record as a marine zoologist. His dehberate opinion, expressed in this 

 book, is that no operations possible to man can have any appreciable effect in 

 reducing the productivity of a fishing ground. One must, because of the 

 personal authority of our author, hesitate to differ from him. 



Nevertheless, many people do differ. The Scottish Fishery Board, a body 

 with great traditions and capable of very sound judgments, does differ, and so 

 would most owners of steam fishing vessels. Without doubt a fishing ground 

 can be rendered less profitable from the commercial point of view by long- 

 continued and increasing exploitations. Much depends on a precise statement 

 as to what one means by " depletion," " impoverishment," or " loss of 

 productivity," and so far no one has been able to give us a satisfactory 

 analysis of these conceptions. 



This book is pubUshed in 1920 — after a very interesting though undesired 

 experiment on the great scale. In August of 19 14 it became necessary, for 

 military reasons, to prohibit trawhng over large areas of the North Sea, the 

 Irish Sea, and the English Channel. Fishing, therefore, fell off to an enor- 

 mously greater extent than could have been possible in any designed experi- 

 ment. How did the stock of fish on those grounds, that had presumably 

 been depleted by the last thirty years' trawling, recover during the four years 

 of partially suspended fishing ? The question is being investigated, and I 

 have, myself, examined statistics relating to the Irish Sea. This is pretty clear : 

 if one had not known about the war, and the military restrictions, and had had 

 only those statistics to serve as the material for an opinion, it would have been 

 impossible to deduce that anything had occurred other than the " natural 

 fluctuations " that are always to be seen in the productivity of a fishing 

 ground. This conclusion, if it be sound and is confirmed for the North Sea, 

 must be of significance in respect of Prof. Mcintosh's attitude. 



