STUDIES ON THE STRIPED BASS OF THE ATLANTIC COAST 57 



Of especial importance in this respect is the dominant year-class of 1934, probably 

 the largest production of striped bass in a single year in the past half century, whose 

 members appeared along the Atlantic coast as 2-year-olds in 1936 and were at once 

 subjected to the highly intensive fishery that confronts this migratory species over the 

 greater part of its range. Information gathered in the course of this investigation 

 makes it possible to demonstrate that this dominant year-class was directly responsible 

 for a greatly increased catch, and also to make a rough estimate of the approximate 

 rate at which this surplus was removed. Such an estimate is based on the percentage 

 of tag returns from 2- and 3-year-old striped bass of the dominant 1934 year-class. 

 (See pp. 36-41 and tables 17-20.) It includes all the factors which show that the 

 percentage of tag returns on this age-group was far lower than the actual percentage 

 removed by the fishery from 1936 to 1938. (See pp. 15 and 36.) Using this method, 

 the most reasonable approximations show that about 40 percent of the members of this 

 year-class were removed as 2-year-olds, and that at least 25-30 percent of the remain- 

 ing 3-year-olds were taken by the fishery in 1937 and 1938. If these estimates are 

 correct it means that over 50 percent of the 2-year-olds entering the fishery in the 

 spring of 1936 had been removed by the spring of 1938, neglecting the effect of natural 

 mortality, which is taken up below (see p. 59, et seq.), and which is an important 

 factor in the rate of removal of the members of any population. Even though these 

 estimates are only rough approximations, it is plainly evident that the enormous sur- 

 plus created by the production of the dominant 1934 year-class, resulting in the largest 

 catch of many years in 1936 (see figs. 4 and 6), is rapidly being removed, and that the 

 members of this age-group will soon have been depleted to such an extent that they 

 will no longer bolster the annual catch. 



Granting, then, that there has been a sharp decline in the numbers of striped bass 

 along the Atlantic coast despite the occasional appearance of dominant year-classes 

 that bolstered the stock temporarily, it is of interest to know what lias caused this 

 decline. Two factors appear to have been responsible — first, the destruction of spawn- 

 ing areas by pollution and dams, and second, overfishing. Let us now consider these 

 two factors in some detail. 



There can be little doubt that striped bass formerly entered and spawned in nearly 

 every river that was suitable along the better part of the Atlantic coast. As civiliza- 

 tion advanced, dams were built, many of the streams were polluted, and the number 

 of spawning areas that were available became less and less. It has been pointed out 

 under the section on spawning habits and early life history, and elsewhere in this 

 paper, that the majority of the spawning areas for striped bass are now confined to 

 the coastal rivers from New Jersey south. There remain, however, a few isolated 

 localities to the north that are still suitable — probably but a fraction of the areas 

 that were once available. Yet it is clear from the production of the dominant 1934 

 year-class that there are still a sufficient number of good spawning areas left along 

 the whole Atlantic coast to produce a large supply under the proper conditions. It 

 should not be necessarj- to emphasize the fact that these remaining localities should 

 be carefully protected against anything that might damage them, and other areas 

 should be restored if it is possible. 



Further investigations on the striped bass should continue the study of spawning 

 areas along the Atlantic coast and determine the necessary requirements for the nor- 

 mal production, fertilization, and development of the eggs and larvae. In the case 

 of some of the isolated spawning areas in northern waters, where the stock appears 

 to have been maintained by a more or less self-supporting and partially resident popu- 

 lation, there is some evidence that intensive winter and spring fisheries on the supply 

 in the spawning localities have practically exhausted the stock. Under normal con- 

 ditions the populations north of Cape Cod are probably not increased to any great 

 extent by migrants from outside — especially from the south. This only occurs under 

 exceptional cases, although it may occur more commonly in the future now that the 

 ("ape Cod canal provides an easy means of access to the north (see p. 41). Thus an 

 intensive fishery in the winter and early spring when the members of such an isolated 

 self-supporting stock are dormant and inactive, and hence more easily available for 

 capture, may come close to entirely depleting a population of this sort. 



Turning to the other factor, overfishing, which in conjunction with the destruc- 

 tion of spawning areas by dams and pollution has been responsible for the decline in 



