168 DESCRIPTION OF IMPORTANT FISHERIES AND THEIR PRODUCTS 



Usually two men handle a southern shrimp boat, although three may 

 be employed, especially in offshore operations; in a few cases vessels 

 have been handled by one man. 



Fishing for white shrimp takes place mostly during the day while the 

 best catches of pink and brown shrimp are made at night. In some areas, 

 including North Carolina to northeast Florida and parts of the Gulf of 

 Mexico, vessels return to port each day. In the Tortugas fishery, boats 

 are usually on the fishing grounds for periods of four to seven days or 

 longer; in the Campeche fishery the usual length of trip is 45 days. In 

 the case of these long trips, vessels send their early catches to port with 

 other boats, transferring loads about every seven days. In turn, a vessel 

 will ordinarily carry part of the catches of several others when they 

 complete their trip. 



The length of time that the net is dragged varies considerably but is 

 ordinarily about two to three hours. In addition to shrimp, the nets 

 pick up considerable quantities of "trash," including fish, sponges, crabs, 

 and other animals, plus stones, shells, and other material. The trash 

 may constitute a major proportion of the catch, the amount varying 

 with locality and season. Much of the material caught in this way would 

 make meal which is useful in poultry feeds or could be used for animal 

 feeds or to manufacture other useful products. So far no proven method 

 has been devised for the economical collection and processing of this 

 material, but autoenzymatic breakdown at a low pH may be usefuP'^. 



Handling on the Vessels 



When the trawl net has been dumped on the deck of the vessel, the 

 shrimp are separated from the trash (Figure 12.2) and the latter is 

 dumped overboard. In the southern shrimp fishery the shrimp are 

 usually beheaded on the boat, but if the catch consists of large quantities 

 of small shrimp or if the vessel expects to return to port without delay, 

 this may not be done. The shrimp are put into metal baskets of about 

 85 pounds capacity and washed with a stream of sea water from a hose. 

 They are then stored in the hold of the vessel in crushed ice. 



Temperatures are high in the southern areas where most of the shrimp 

 are caught, with water temperatures ranging up to about 85°F and air 

 temperatures rising to the 90's. Temperatures on the metal decks of 

 some vessels reach higher levels than this. As a consequence, shrimp are 

 damaged if they are not (|uickly handled. Bacterial and autolytic spoil- 

 age, as well as a condition known as ''black spot," may be well advanced 

 before the shrimp reach shore unless care is exercised ^^. 



Black spot is a condition affecting the shell of shrimp and, in severe 

 cases, also causing discoloration of the flesh. It usually appears as a 



