The Effect of Circle Hooks and Straight (J) Hooks on the Catch Rates and Numbers of White Marlin and Blue Marlin Released Alive by the U.S. Pelagic Longline Fleet in the Gulf of Mexico

Abstract

The effect of circle and straight (J) hooks on the catch rates of white marlin Kajikia albida (formerly Tetrapturus albidus) and blue marlin Makaira nigricans and the proportions released alive by the U.S. pelagic longline fleet targeting yellowfin tuna Thunnus albacares in the Gulf of Mexico was assessed with data collected by scientific observers aboard commercial vessels between 1992 and 2004. Catch rates were lower with circle hooks than with straight hooks, but the differences were not significant; while the catch rates of the targeted species, yellowfin tuna, were the same for both hook types. However, a significantly higher proportion of marlins was released alive from circle hooks than from J hooks.