Standardized catch rates for blue shark (Prionace glauca) from the Venezuelan pelagic longline fishery in the Caribbean Sea and adjacent waters of the North Atlantic Ocean: Period 1994-2013
Indices of abundance of blue shark (Prionace glauca) from the Venezuelan Pelagic Longline fishery are presented for the period 1994-2013. The index of number of fish per thousand hooks was estimated from numbers of blue shark caught and reported in the observer data forms recorded by scientific observers aboard longline (Venezuelan Pelagic Longline Observer Program) vessels since 1994, and from INSOPESCA’s Observer Program for 2012-2013. The standardization analysis procedure included the following variables; year, vessel, area, season, bait, and approximate fishing depth. The standardized index was estimated using Generalized Linear Mixed Models under a delta lognormal model approach. The standardized CPUE series show that the relative abundance of blue shark increased in the early part of the series (19972000) followed by a decline from 2001 until 2006 with the lowest value in 2005, and some recovery in the latest years of the series.