Standardized Catch Rates for Bigeye Tuna (Thunnus obesus) From the Pelagic Longline Fishery in the Northwest Atlantic and the Gulf of Mexico

摘要

Two indices of abundance of bigeye tuna from the United States pelagic longline fishery in the Atlantic are presented for the period 1981-2001: An index of number of fish per number of hooks (thousand) estimated from numbers of bigeye tuna caught and reported in the Pelagic logbooks data. And, a biomass index (dress weight) per number of hooks (thousand) estimated from the weight-out data. The standardization analysis procedure included the following variables; year, area, season, gear characteristics (light sticks, main line length, hook density, etc) and fishing characteristics (bait type, operations procedure, and target species). The standardized index was estimated using Generalized Linear Mixed Models under a delta lognormal model approach.