the adoption of the wider mesh in 1953, 

 the annual catch uould increase 25 to 30 

 percent over the average yield before 

 adoption of the new mesh. This has not in 

 fact yet taken place. The reason has been 

 a poorer brood recruitment following the 

 adoption of the mesh. No definitive 

 reasons have been advanced for the lower 

 broods. Biologists have no reason to ex- 

 pect that environinantal conditions will 

 return to a more favorable situation idiich 

 would provide average or above average 

 recruitment, 



2. Maximum Annual Yield On Georges Bank 

 And Its Effect On Fishing Costa 



Basic to an understanding of the cost 

 of fishing in terms of effort and produc- 

 tion, is appreciation of a principle well 

 accepted by fishery biologists. This 

 principle is that there is a maximum 

 sustained annual yield (catch) in any fish - 

 ery, such as the Georges Bank haddock £Lsh- 

 ery. Further, this total equilibrium or 

 sustaiiied yield in any year can be taken 

 within a wide range of fishing effort , ^If 

 tne average annual elfort expended for 

 haddock on Georges Bank between 1931 and 

 1958 is called normal or 100 percent^ then 

 total fleet landings in normal brood years 

 will not vary significantly between a 

 fishing effort level ranging between 75 

 and 200 percent of normal. That is, the 

 maximum annual sustained yield can be ex- 

 pected w h ether fishing effort is 5,000 or 

 15,000 t"rawler days . The catch per vessel 

 may, of course, vary substantially. Ahy 

 effort by the fleet, however, above the 

 minim\m necessary to obtain the equilibrium 

 yield becomes siirplus higher cost fishing. 



In the case in point, biologists have 

 determined that with brood years similar 

 to those experienced between 1931 and 19li8, 

 the equilibrium yield of Georges Bank 

 haddock should be about 120 million pounds. 

 Before adoption of the mesh regulation the 

 eq\illibrium yield was about 9li million 

 pounds, again based on the average brood 

 recruitment between 1931 and 19li8, 



It must be kept In mind that the 

 principle of a siistained yield over a 

 wide range of effort is based upon an 

 average yield which assumes a given or 

 "normal" level of recruitment and normal 

 brood years. The declining yields in 

 recent years do not weaken this principle. 

 The poor catch has been due to successive- 

 ly poor brood years resulting from as yet 

 unknown environmental factors. If the 

 decline in brood recruitment continues, 

 there will still be an equilibrium yield 

 attainable over a wide range of effort. 

 The maximum yield will, however, be at a 

 lower figure than that formulated on the 

 basis of the "normal" 19 JL-IS brood years. 



!nie Idea of a maximum annual yield 

 may be clearer if one considers that 

 "the numbers of fish added to the stock 

 set a limit to the total landings which 

 can be taken from the banks. As soon as 

 enough days are put in to catch this 

 limit, any additional fishing effort does 

 not increase landings...." 12/ The total 

 merely must be shared by more units. 



The principle is formulated by Dr. 

 William F. Thon^json in the following 

 excerpt from "The Effect of Fishing on 

 Stocks of Halibut in the Pacific ." 



"The evidence of the halibut fishery 

 is strongly supported by the history of 

 fisheries in general. Those of such areas 

 as the North Sea have shown a tendency 

 toward relative constancy in total yield 

 throughout the period of great technolog- 

 ical in^irovement and expansion of the 

 fishery. It Is a tendency shared by the 

 fisheries of the North Atlantic as a 

 whole and of other regions. 



"It has given rise to prolonged 

 argument as to whether production has 

 fallen as a resiiLt of heavy fishing. It 

 was, indeed, assumed that this iroiild be 

 the case by those who in early times 

 urged conservation. This decline, if 

 existent, has not been of a magnitude to 

 be obvious without careful analysis of 

 extensive statistics covering many years. 



75/ Statement of Robert A, Nesbitt before the United States Tariff Commission. 

 19^, pp. 12-13, 



U3 



