Until comparatively recent years the mouths of all shrimp 

 trawls vera rGctangular, the load or bottcm lino and tno float or 

 corK line boing more or loss straight horizontally, A new design, 

 however, has the float lino fointiing a pronounced arc when the trawl 

 Is in operation. The former is known as a flat trawl and tlie latter 

 as abriloon trawl. The United States Fish and Wildlife Service has 

 made experiments designed to compare the efficiency of the two trawls. 

 Tho results of these experiments indicated that under similar conditions 

 the catches per hour of the 7li-f oot balloon and the 100-foot flat trawl 

 were abuut the same. The balloon not contained less bottom trash (shells 

 and sponges) and the catch was landed in a better condition. 



The length of the drag and the speed of tho tow vary with 

 depths, bottom conditions, and the speed with which the tail of the 

 net is filled. Generally speaicing, drags in deep waters usually take 

 from 1-1/2 to 3 hours. In the inshore and shallow water fishery, how- 

 ever, drags are sometimes of much shorter duration. 



Gear Preferences 



Preferences for types of gear in the south Atlantic and Gulf 

 shrimp fishery ascertained by Harwell, Knowles and Associates in 1955 

 in connection with a study of vessel efficiency are stated below. 



Balloon and Flat Nets on Shrimp Trawls .— The number of nets 

 fishermen Tind necessary to keep aboard, ship is a function primarily 

 of length of trip and t3rpe of bottoms encountered. In North Carolina, 

 South Carolina and Georgia 1 or 2 trawls are carried; in Florida, Louis- 

 iana and Texas, 2 or 3; and in Mississippi, 2 to 5 nets. 



In tho Carolinas and Mississippi, 2-inch stretch mesh is used, 

 while in Florida, Louisiana and Texas the 2-lA-inch stretch mesh is 

 most coimon. The nets are inada of 15- to 18- thread cotton twine and are 

 usually tarred. The cod end or bag is made up of heavier, 1-to 1-1/2- 

 Inch netting. 



Every fisherman has his o^m preference for net size* The 

 sizes most couiraonly encountered ranf^^d from 90 feat to 110 feat in flat 

 nets and from 65 feet to 85 feet in balloon nets. In Louisiana the 30- 

 foot to U2~foot vessels are equipped with li5-foot to 55-foot flat trawls. 

 The nata used in the Carolinas are also small and are usually about 55 

 feet to 60 feet. In addition to vessel length, vessel power has a bear- 

 ing on the choice of net size. 



In considering the efficiency of a fishing net an investigation 

 cannot be limited to operational efficiency but must include a study of 

 "net use-life". Inquiries have been made to detennine the causes of net 

 losses in various areas. In North Carolina, South Carolina, Georgia, 

 Florida and Texas, the general opinion of fishermen, net dealers, and 



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