THE AMERICAN SHRIMP INDUSTRY 593 



ranging from 18 to 50 feet in depth, and remain at sea from 10 to 15 days, 

 depending upon their success in obtaining a pay load. 



It has been estabUshed that as much as 10 per cent of the catch is often lost 

 because it is bruised and improperly iced while being headed and stored in the 

 hold of the vessel. When shrimp are plentiful and the crew are busy taking care 

 of the catch as it is hauled aboard, it is not possible to find time to remove the 

 heads before packing the shrimp in ice. This results in a much more rapid spoilage 

 since bacteria and enzymes from the viscera infect the remainder of the shrimp 

 and cause rapid softening. Another type of spoilage occurs when the shrimp are 

 held in ice over a prolonged period, and results in a distinct stale shrimp odor. 

 At the same time a black discoloration often develops on the flesh directly under 

 the shell. In extreme cases this black discoloration causes a similar discoloration 

 in the water from the melting ice flowing over the shrimp, and is known as "black 

 drip." If the shrimp are left uniced on deck for a prolonged period, they develop 

 a red discoloration under the shell, and are known as "red shrimp." These are 

 recognized as unmarketable by all shrimp fishermen. 



Method of Capture 



Prior to 1912-15 most shrimp were taken in haul seines. About this time, at 

 the Beaufort, N. C. biological station, the small otter trawl came into use for 

 gathering specimens for study. The otter trawl was so successful in taking shrimp 

 that the industry began to adopt this method in preference to the haul seine. The 

 first commercial operation to make use of the otter trawl was located at Fernandina, 

 Fla. Seines were so rapidly replaced by the trawl that in the early 1930's only a 

 few remained in operation; at present none is in use. 



The introduction of the trawl is of considerable economic importance in the 

 development of this fishery. The haul seine could be used only in relatively shallow 

 water and required a large crew of men, while the otter trawl is handled by a 

 small crew and can be used in deep water. The catch is considerably greater with 

 a trawl since its use made possible the opening of new fishing grounds. In the deep 

 water of the Gulf the schools of shrimp are located by means of a small "try net," 

 which is similar in construction to the large trawl. This saves time and efl^ort as 

 the large trawl is not put overboard unless there are good indications that a quan- 

 tity of shrimp is in the area. 



Power boats of various sizes are employed in the otter-trawl fishery, but as a 

 rule the crew consists of 2 men. Many small boats, however, with crews of 1 man 

 each, successfully engage in this fishery, while a few of the larger boats carry 

 3 men. 



As the vessel leaves port for the fishing grounds, the net is arranged on deck 

 at the stern, the mouth of the bag being placed on deck first and the tail end on 

 top. The otter boards are placed on either side of the deck, bridles up, and the tow- 

 lines are coiled in the hold. When drags with the try net indicate sufficient quan- 

 tities of shrimp are present, the engine is slowed down so that the boat does not 

 travel more than from 2 to 4 miles per hour. The tail end of the net is first thrown 

 overboard and the remainder of the trawl quickly follows, the boards being the 

 last to go. The amount of towline let out in hauling the trawl varies, being 

 usually about 3 times the depth of the water. The lines are attached to cleats on 

 either side of the vessel, the point of attachment varying in the different boats. 



