da^m and at dusk, or in muddy water, when both species may bo taken in a 

 single drag, brown shrimp are usustlly caught in night drags while white 

 shrimp are talcon in the daytime. A fevi pinlc shri-np are found in the west- 

 ern Gulf of Mexico, amd the range of the brcm shrimp may extend into 

 the eastern Gulf, but the commercial importance of these out~of -range 

 shrimp is not known, perhaps because of the limited observations of 

 fluctuating availability. 



Broim shrimp have been taken in 8^ percent of all exploratory 

 drags made by the "Oregon" in depths of 10 to 70 fathoms between Cape 

 San Bias, Florida, westward and southward on the continental shelf to 

 Carmen, Mexico. 



The area that has repeatedly yielded the highest catch rate of 

 broim shrimp lies in the 30-to U5-fathom depth range between 88° and 90° 

 west longitude on both sides of the Mississippi Delta. Until 1952 some 

 sections in this area were only partly fished becaxise the soft mud bottom 

 bogged trawling gear. After the introduction of the "mud rope", however, 

 the entire area was being fished. 



Eastvmrd from 88° west longitude (east of Mobile) catch rates 

 diminish rapidly. No catches of brown shrimp were made east of Cape San 

 Bias, Florida. 



Westward from the Delta, all grounds that seasonally have com- 

 mercially valuable stocks are being worked by the Texas and Louisiana 

 fleets. Beyond the present depth range of this fishery, in 35 to 50 

 fathoms, there are extensive areas of good trawling bottom. Catches of 

 the "Oregon" in this area averaged only 20 to 50 pounds per hour, a 

 quantity which is considered below the present minimtun catch rate for 

 offshore shrimp vessels. 



Off the Alabama, Mississippi, Louisiana, and Texas coasts the 

 steep slope of the continental shelf beUreen 70 and 100 fathoms makes 

 trawling difficult or impractical. 



Beyond 50 fathoms out to the edge of the continental shelf 

 poor trawling bottom was encountered by the "Oregon" in its latest trips. 



Hildebrand goes into considerable detail in outlining the 

 expanse of the fishing grounds for broxm shrimp in the Gulf. His descrip- 

 tion of the fishing grounds is based on the results of his oim explora- 

 tions and on information supplied to him by commercial fishermen in the 

 area. The maps prepared by him do not show the fishery for small brovm 

 shrimp in the protected waters of the bays and in depths of less than 

 twelve fathoms since no separate statistics on this part of the fishery 

 exist. He emphasizes, though, that at times large landings of small, UO- 

 65 count, shrimp are made in Louisiana and East Texas ports, (see figure 

 1-8) 



26 



