PROGRESS IN BIOLOGICAL INQUIRIES, 1939 ol 
and the 100-fathom contour from the Mexican border to Carrabelle, 
Fla. Throughout this stretch of bottom 380 hauls, of one-half hour 
duration each, were made with a 9-foot otter trawl. The trawl 
actually was dragged over 1,200 miles of ocean floor. In addition 
to trawling, the Pelican occupied 70 hydrographic stations at which 
158 salinity samples, 51 Petersen dredge samples, 51 mud samples, 
and 20 bottom-core samples were taken, together with temperature 
observations at each station. 
Again, as in 1938, concentrations of large shrimp were found off 
the central Louisiana coast near the 10-fathom line between Ship 
and Trinity Shoals. No comparable aggregations were found along 
the entire length of the Texas coast. East of the Mississippi River, 
between Mobile, Ala., and Carrabelle, Fla., the catch was even less 
than along the Texas coast. At no time were common shrimp taken 
in depths greater than 15 fathoms. 
These results indicate that the common shrimp does not go to 
any great depths; that the shrimp boats working in the offshore 
Louisiana area extend their fishing operations to the outer limit 
of the range of the common shrimp; that there appears to be little 
likelihood of other offshore fishing areas being developed in the 
Gulf with a magnitude comparable to that now present between 
Ship and Trinity Shoals; and that bottoms composed primarily of 
sand, shell, or coral do not provide a suitable habitat for the shrimp. 
Since it has been determined that the common shrimp does not 
inhabit’ areas in the Gulf of Mexico that are outside of the range 
of operations of Launch 458, it was decided that further work with 
the Pelican would be unnecessary in the Gulf. However, similar 
offshore studies on the distribution of shrimp along the Atlantic 
coast also are needed, for the same reasons that they were required 
in the Gulf. The Pelican will be transferred to the East coast in 
January 1940, for the purpose of performing exploratory trawling 
out to the 100-fathom contour between Fort Pierce, Fla., and Cape 
Hatteras, N. C. When this exploratory work has been accomplished 
we will be in a position to recommend what, in our judgment, ap- 
pears to be the best method for the management of the Atlantic 
coast shrimp fishery. 
MIGRATION STUDIES 
As shown by tagging experiments, the Florida winter fishery is 
comprised of migrants from as far north as North Carolina. Before 
the migrating shrimp can reach their Florida winter ground they 
first must run the gamut of the fishery along the entire stretch of 
coast from their nursery ground to their winter ground. The fishing 
intensity has been so severe during the past few years that only a 
small portion of the shrimp that start out on this migration ever 
reach their objective. 
Since the shrimp definitely is migratory, the solution of the At- 
lantic coast problem les not within the individual responsibility 
of any one State but must be the accomplishment of unified action 
on the part of all four of the States involved. Until the current year, 
although suspected, it was not known whether similar united action 
would be advisable in the Gulf of Mexico in case the need arose. 
However, tagging experiments conducted in Louisiana, Mississippi, 
