the net is being towed. European and American 

 experiments have demonstrated convincingly 

 that this can be accomplished by increasing 

 the size of mesh, particularly in the cod 

 end (Davis, 1934; Herrington, 1935). 



It is acknowledged that the adoption of 

 such a modification in gear by the winter 

 trawl fishery involves careful consideration 

 of all conditions under which the fishery 

 operates. Foremost among these is the fact 

 that the catch of this southern fishery con- 

 sists of several different species differing 

 markedly from each other in shape and length. 

 In addition to scup, the catch is composed of 

 sea bass, fluke, croakers, and lesser quan- 

 tities of butterfish (Poronotus tricanthus ) and 

 squeteague (Cynoscion regalis). It is the opinion 

 of many of the fishing captains engaged in the 

 winter trawl fishery that a change to a larger 

 size of mesh in the cod end in excess of that 

 now in use would cause the loss of market- 

 able sizes of fish other than scup. For ex- 

 ample, it is their belief that increase in size 

 of mesh of the cod end above present dimen- 



sions (2-1/2 to 3 inches stretched measure- 

 ment) would result in the loss of the small 

 but marketable- sized butterfish and squeteague 

 by escapement through the mesh and the loss 

 of good "market croakers" by gilling. Hence, 

 the importance of "saving" the small and 

 undersized scup relative to the catch as a 

 whole is a debatable question. 



On the other hand, in some winters, de- 

 pending on conditions, scup constitute a major 

 portion of the catch. In addition, especially in 

 recent years, it has comprised an important 

 part of the catch of the summer inshore 

 fishery, particularly along the New Jersey 

 coast, and in some regions, as in Rhode 

 Island, for years has accounted for prac- 

 tically the total catch of the principal fish- 

 eries of the region. Because of the importance 

 of scup in the summer and winter fisheries, 

 it is advisable to determine whether the 

 prevailing destruction of the young and small 

 sizes can be effectively reduced and whether 

 this can be done without excessive loss of 

 other market species. 



SUMMARY 



1. The scup population of the Atlantic coast 

 constitutes an important part of the catch of 

 a fishing industry of major commercial and 

 recreational importance. 



2. The total catch over the past 50 years 

 has fluctuated widely and abruptly within 

 relatively short periods of time. 



3. The catch per unit of effort has also 

 fluctuated widely, because of changes in avail- 

 ability which, in the summer fishery, resulted 

 principally from changes in abundance and, 

 in the winter fishery, from changes in move- 

 ments of the fish. 



4. Fluctuations in the catch of the summer 

 fishery were due mainly to differences in the 

 size of the increments added to the population 

 by succeeding year classes, which apparently 

 has been caused by variations in the relative 

 success of reproduction of annual broods. 



5. Fluctuations in the catch of the winter 

 fishery were due mainly to differences in 

 the amount of cooling of the water over the 

 general fishing area in the several winters, 

 scup being more available in a cold winter 

 by being more concentrated in a relatively 

 small and easily accessible part of the 

 ground. 



6. Although the fluctuations in catch of 

 the summer and winter fishery have resulted 

 from different causes, results of tagging and 

 observations of size composition reveal that 

 both fisheries draw on the same general 

 stock. 



7. The stock of scup is now (1935) at a 

 high level of abundance despite the much 

 increased fishing activity of the past 5 years, 

 the increase resulting mainly from the devel- 

 opment of the winter fishery and from the 

 Increased activity of the summer otter trawl 

 fishery. 



58 



