PROGRESS IN BIOLOGICAL INQUIRIES, 1939 25 
Maryland increase their size limit to the Bureau’s recommendation 
of 16 inches to insure more efficient utilization of the supply. The 
increased size limit will result in a greater total catch and value, 
provided by an equal number of fish of the same year class. 
A survey of the coastal regions of Chesapeake Bay to southern 
New England during 1939 confirmed conclusions resulting from 
previous study that not all important areas for striped bass furnish 
their quota of young to replace the larger-sized fish removed by the 
fishery. Spawning grounds of significant importance were located 
in the Maryland waters of Chesapeake Bay, Delaware Bay, and the 
lower Hudson River in New York. According to studies made in 
previous years, the lower Chesapeake Bay and the sounds and coastal 
rivers of North Carolina are also productive areas. Results of the 
survey in 1939 indicated a notable lack of successful reproduction of 
striped bass along the ocean coasts of New Jersey, Long Island, and 
southern New England. These observations suggest that the adult 
stock in these latter regions originates mainly from the migration 
of young fish from the more productive spawning and nursery areas 
of Chesapeake Bay, and possibly Delaware Bay and the Hudson 
River. 
The survey also revealed that spawning in 1938 and 1939 in the 
important Chesapeake Bay region was relatively unsuccessful, de- 
spite the fact that the spawning stock was one of the largest on 
record. This was in marked contrast to the unusually successful 
reproduction that occurred in 1934, when the stock of adult fish was 
relatively low. This disclosure supports the results of previous 
studies in that the production and survival of young striped bass 
are, to a large extent, independent of the number of spawners, and 
hence regulatory measures to increase the spawning stock are not of 
primary importance in the proper conservation of the species. The 
Bureau’s recommendation of a 16-inch size limit will, however, in- 
crease the number of spawners, but it is intended more specifically 
to insure better utilization of each brood. Results of the study of 
spawning and nursery areas for striped bass, and of tagging experi- 
ments to determine the extent of the withdrawal on the stock and 
additional information on the seasonal migratory habits of the spe- 
cies, have been considered in connection with the question of whether 
more restrictive legislation intended to improve or maintain the 
abundance of striped bass is necessary in some of our Atlantic Coast 
States. 
Shad.—Further study in 1939 confirmed the opinions expressed 
in the report for 1938 to the effect that the principal cause of de- 
pletion is overfishing, rather than pollution or obstruction of runs, 
and that recovery can best be brought about by providing a spawning 
escapement substantially equivalent to that which has proved ade- 
quate in the Hudson River. 
Study in 1939 also brought out the important point that the mod- 
erate fishing rate in the Hudson eventually takes as much shad from 
each year class as the more intensive fishery in Chesapeake Bay, but 
spreading the catch over several years allows six times as much 
spawning from each year class. 
In December 1939, a memorandum was submitted to the conserva- 
tion departments of Maryland, Virginia, and North Carolina, sum- 
