英文摘要 |
In this study, we applied generalized additive model (GAM) to analyse the abundance variation of D. gigas in the Southeast Pacific using temporal, spatial and environmental variables. The optimal model for inter-annual variation of CPUE (2002-2004) includes all variables, and can explain 12.4% variance. The abundance of D. gigas showed an increase in 2002-2005, decrease in 2005-2007, and increase after 2007. The squid abundance decreased from January to June and increase from July to December. The higher CPUE occurred towards equatorial and coastal regions. The optimal models for intra-annual variation of CPUE include all variables, and can explain 8.4-34.2% variance in 2002-2008. The spatiotempoal patterns and influences of environmental variables for squid abundance are similar among years, except 2005 and 2006. The higher abundance and narrower range of distribution in 2005 might be related to the occurrence of warm episodes in the east equatorial Pacific. |