The longline CPUE series for Inaccessible and Gough islands are GLMM standardised through to 20191. For Nightingale, the fishery was closed for the 2011 season and catches were set at precautionary levels for the 2011 and 2012 seasons. The Nightingale GLMM model thus excludes 2011 and 2012, although it now includes 2013-2019 for this island. 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. The standardised CPUE for Inaccessible continues to be high, and shows a slight increase since the previous season. For Nightingale and Gough, the standardised CPUE value for the current season is lower than that of the previous season, although the Nightingale CPUE remains well above the Itar value. The Gough CPUE has been below the Itar value for the past four seasons.
1 The convention used here for split seasons is to use the first year, i.e. 2013 refers to the 2013/2014 season.
History
Department/Unit
Department of Mathematics and Applied Mathematics, University of Cape Town