GLMM- and GLM-standardised lobster CPUE from the Tristan da Cunha group of islands for the 1997-2012 period.
The longline CPUE series for the three outer islands are GLMM standardised through to 2010. Year, month, area, trap-type, soak time, depth and year-area interactions are treated as fixed effects, and year-month interactions treated as a random effect. For Tristan, for which the available powerboat data are more limited, a GLM with year and month as fixed effects is applied. After initial increase, the standardised CPUE indices show drops over the most recent years for all islands – although for Gough, this decrease is only seen in the most recent 2010 season’s data.