Standardized catch rates in biomass for the South Central and Western Pacific swordfish (Xiphias gladius) from the Spanish longline fleet for the period 2004-2006.

Abstract

Standardized catch rates in weight were obtained using General Linear Modeling (GLM) from sets carried out by the Spanish surface longline fleet targeting swordfish in the South central and South western Pacific areas during the 2004-2006 period. Year, quarter, area, ratio between swordfish and blue shark species and gear were used for modeling. The model tested explained 75% of CPUE variability. As in the case of the Atlantic, most of the CPUE variability was attributed to the ratio between the two species and secondly, tothe gear factor. Other significant, although less important factors were quarter and area and the interaction between the two, while the year was considered the least important of all the factors examined during this period. The time period covered is too short to be able to lead to any conclusions on the standardized CPUE trend, but the results suggest that activity was stable during the Spanish fleet’s initial period of operation in these regions.