BUREAU OF IISHERIES 99 
and the attendant effects on the commercial stock available to the 
fishery. Information has also been obtained on the migratory, 
spawning, feeding, and schooling habits of the mackerel, and prog- 
ress has been made toward discovering the relationship between the 
northern and southern subdivisions of the stock which have been 
found to have an important bearing on availability to the fishermen. 
During the 1936 season the abundance of mackerel remained at a 
fairly high level, although the total catch, 40,173,400 pounds, repre- 
sented a decrease of 24 percent as compared with the previous year. 
During the first half of the 1937 season the decline has been even 
more marked, and appears to be too severe to be ascribed to varia- 
tions in year-class survival. Without hydrographic work from a re- 
search vessel, however, the abundance of yearling mackerel, often a 
determining factor in the success or failure of a fishing season, must 
remain an element of uncertainty in the predictions made each year 
by the Bureau. 
Because of the migratory habits of the shore fishes of the Middle 
Atlantic region, the division of jurisdiction among many States, and 
the interstate traffic in the products of the fishery, the problems of 
this area are far beyond the scope of the conservation organizations 
of the several States. In recognition of this fact, leaders of the fish- 
ing industry and of angler organizations have united during the year 
in urging that the Bureau of Fisheries undertake scientific and eco- 
nomic studies necessary for formulation of a conservation policy to 
arrest the evident depletion of several important species. 
From data collected between 1927 and 1935, a comprehensive study 
of the problems of squeteague or weakfish conservation has been com- 
pleted. Observations have been continued on the new and important 
winter trawl fishery off the Virginia Capes. During the 1937 season, 
an observer spent considerable time at sea aboard fishing boats col- 
lecting detailed information on fishing activities and composition of 
catch as to kind, quantity, and sizes of fish; and gathering data on 
various types of trawls with particular attention to the need for and 
practicability of modifications in size of mesh to insure release of 
undersized and unsalable fishes, especially scoup and sea bass. 
In response to general complaint of depletion of the winter 
fiounder, the Bureau is beginning investigations of the life history 
and conservation needs of this species. During the spring of 1937, a 
tagging experiment was undertaken to obtain information on the sea- 
sonal migrations of flounders and to gain some measure of the in- 
tensity of the fishery. 
Shrimp investigations on the South Atlantie and Gulf coasts.— 
Total catch statistics collected for the important shrimp fishery of 
the South Atlantic and Gulf coasts reveal the fact that the yield is 
not increasing in proportion to the increase in fishing effort. This 
fact, considered in relation to the scarcity of spring shrimp that has 
prevailed during the past three seasons, indicates a heavy drain on 
the fishery. 
The tagging program, designed to secure data on migrations, 
growth rate, and fishing intensity, has been continued on both the 
South Atlantic and Gulf coasts. Returns from tagging, together 
with leneth-frequency data that have been collected, indicate that on 
the South Atlantic coast the shrimp move from the area of southern 
South Carolina, Georgia, and northern Florida to the central Florida 
