PROGRESS IN BIOLOGICAL INQUIRIES, 1939 17 
Island waters. During 1939 a series of fish also was tagged in John’s 
Bay, Maine. In gener al, tagging experiments indicate offshore migra- 
tions of the winter flounder in the spring, and inshore spawning 
migrations in the fall. Although there was some slight dispersion 
of fish from local areas, the majority never ventured far from home 
waters. 
Racial studies of the flounders in the Long Island area, during the 
summer of 1939, confirmed the existence of local populations in the 
Peconic Bay, Great South Bay, and Long Island Sound regions, as 
indicated by the tagging experiments. 
ANALYSIS OF GROUNDFISH ABUNDANCE 
The groundfish abundance analysis was continued under the direc- 
tion of Dr. Rounsefell, who was assisted by Mr. Bearse. During 1939 
the fishing vessels landed 376,000,000 pounds of groundfish at Boston, 
Gloucester, and Portland. Compared with 1938, when 379,000,000 
pounds were landed, this represents a decrease of less than 1 percent. 
However, the value to the fishermen rose from $8,352,000 in 1938 to 
$9,017,000 in 1939; an increase of 8 percent. 
An outstanding feature of the 1939 fishery was the continuing ex- 
pansion of the rosefish catch. In 1933 une catch was less than 300,000 
pounds, and in 1934 it was just under 2,000,000 pounds. In 1935 the 
filleting of rosefish gave the product access to the markets of the 
Midwest—where they are sold as “ocean perch”—and the catch rose 
to 17,000,000 pounds. In 1936 it jumped to over 66,000,000 pounds, 
which was almost too large for the market to absorb. In 1937 the 
catch fell off to 58,000, 000; in 1938 it was 65 000,000 pounds; and in 
1939 was 77,600,000 pounds. 
Waking: 1939 the large otter trawlers, which have a long cruising 
radius, commenced taking large quantities of rosefish off eastern 
Nova Scotia, especially in The Gully, just south of Banquereau. 
From July to December 1939, this area accounted for over 8,400,000 
pounds, or 58 percent, of the rosefish catch of the large trawlers, 
whereas it accounted for only about 1 percent of their cateh during 
like periods in 1937 and 1938. 
The various species of groundfish form the basis of the most im- 
portant New England fisheries. Although it has been known that the 
total yield has fluctuated, our knowledge has been too limited to know 
the causes, or which species are most. affected. The shift in the 
fishery within the past few years toward rosefish and grey sole, for 
instance, presents the problem of discovering what effect these changes 
are having on the species that were already being intensively ex- 
ploited. Indices of abundance are being determined for each species, 
which are so constructed that they may be added to from month to 
month to show any sudden changes. Under a system which made 
only irregular summaries of abundance those changes might be un- 
noticed for a long period. When the indices are completed, how- 
ever, it will be possible, as soon as the requisite knowledge of the 
life history becomes available for each species, to suggest means of 
maintaining the population at that level which will yield the largest 
sustained annual catch. 
