71 



fishing. Similarly, the striped bass has been practically extermin- 

 ated on parts of the New England coast, though holding its ot.ti better 

 along the southern shores; the catch crf lobsters per unit of effort 

 has greatly declined since early days, and the smelt fails to hold its 

 o'Jm. In north European waters this is equally true of the plaice. 

 In this case the avere.ee size of the individual fish caught has also 

 declined, and it ^vas this decline in the plaice fishery, with the fears 

 felt for the future of other equally important fisheries in the North 

 Sea, that led the nations bordering on the latter to organize the 

 International Council for the Exploration of the Sea in 1902 (page 1)3.7 ) 



Other coiT.mercial developments on land may also damage the fishery. 

 The effects, on shell fish beds, of pdELution either by sewage or by 

 industrial wastes is often serious; sometimes directly, sometimes in- 

 directly as when the oysters or clams are contaminated with bacteria 

 of diseases. The damming of tidal estuaries may also have a destruc- 

 tive effect, not only within, but by altering the circulation of water 

 in the general vicinity. The probable effects of one project of this 

 sort on the "sardine" fishery and packing industry for young herring 

 in the region of the Bay of Fundy (a two-million dollar industry, based 

 on one of the most important local fisheries of the Atlantic coast of 

 Forth America), is now causing concern to the Fisheries Services of 

 Canada and of the United States. The difficulty is that the detailed 

 understanding of the biology of the herring, and of the hydrography of 

 the region that is needed for positive prediction, is lacking. 



It is obvious that when any species is being fished down below 

 the limit of safety, the rem.edy lies in regulation of the fishery, 

 in order to allow the stock to recover; whether by closed seasons, by 

 closed areas, or by otherwise limiting the catch. 3ut regulation of 

 this sort invariably must cause great disturbance, loss ajn.d hardship 

 to the fishing industry. It is, therefore; of great importance fromi 

 the eccn^uic standpoint to be able to state whether a shrinkage in the 

 catch of one or other of the important species does actually mean that 

 depletion i-s in progress. It is true that in the past any sudden 

 decrease in the yield of the fisheries has usually been blamed, forth- 

 with, to overfishing, or to the development of modern m.ethods more 

 effective than those of the past. In fact, whenever any improved 

 method of fishing is introduced, a wail of calamity arises; it is 

 claimed that the young fish are destroyed, the sea bottom disturbed, 

 etc. etc. and investigation is demanded. Such an investigation of the 

 otter-trawl fishery is, in fact, in progress in Canadian waters at 

 present, though this method has been employed for many years off the 

 United States"and northern Europe. But when it happens, as it often 

 has in the past, that the stock of some fish that had been at a low 

 ebb over a period of years, reestablishes itself in the face of a 

 fishery perhaps even increasing in intensity, it is clear that some 

 factor other than overfishing is at work. In such cases it is the 

 industry that requires protection more than the fish. It has, indeed, 

 been amply proven that the stocks of many sea fishes (perhaps of ell} 

 may vary greatly in abundance from year to year, or over perj.ods of 

 years, from strictly natural causes, with which the hand of man has 

 had nothing whatever to do. 



Natural fluctuations of this sort have been so freely discussed 

 in fisheries literature during the past quarter century that only a 

 few instances need be m.entioned here. In general, they mirror the fact 



