Using Kappenman\u27s Model to Compare the Relative Fishing Power of 42-Foot Shrimp Trawls and 65-Foot Fish Trawls During Summer and Fall in the Western and North-Central Gulf of Mexico

Kappenman’s fishing power correction (FPC) model was used to compare the fishing efficiency between a 42-ft shrimp trawl and a 65-ft fish trawl towed simultaneously at 985 stations by the National Oceanic and Atmospheric Administration ship Oregon II in the western and north-central Gulf of Mexico. The shrimp trawl was consistently more efficient, both summer and fall, and regardless of whether using no./hr or kg/hr to calculate the FPC factors, for four species of fish, three species of crustaceans, and paper scallops. During summer, the shrimp trawl was more efficient, when using FPC factors calculated using no./hr as the catch per unit of effort (CPUE), at catching 13 of the 42 species of fish, 11 of the 12 species of crustaceans, and paper scallops. It was more efficient at catching 18 of the 42 species of fish, 10 of the 12 species of crustaceans, and paper scallops when FPC factors were calculated using kg/hr as the CPUE. In the fall, the shrimp trawl was more efficient, when using no./hr or kg/hr as the CPUE, at catching five species of fish, three species of crustaceans, and paper scallops. Fishing power correction factors were then compared between summer and fall seasons for 42 species of fish and 16 species of invertebrates. During summer, FPC values ranged from a low of 0.15 for Gulf menhaden to 4.94 for shoal flounder; fall FPC values ranged from 0.05 for yellow box crab to 2.52 for broad-striped anchovy. With the exception of three species, when using number of individuals caught per hour as the CPUE, all FPC factors were significantly different between summer and fall catches