Author:Johnston, S J; Butterworth, Doug SDate:Sep 2017FISHERIES/2016/SEP/SWG-DM/51 provided a full description of the current stock assessment model for the South African Horse Mackerel. FISHERIES/2016/SEP/SWG-DM/52 reported updated 2016 assessments for a number of model variants where the ...Read more
Author:Johnston, S J; Butterworth, Doug SDate:Aug 2017The 2017 assessment of the resource is updated given two further years of data now available. Recruitment is estimated to have increased over the last two seasons compared to the previous three seasons when recruitment was estimated to be ...Read morecb
Author:Johnston, S J; Butterworth, Doug SDate:Jul 2017The performances of a number of OMP candidates are reported here. Simulation results do not vary much amongst the various candidates. For this and other reasons it is recommended that at this stage CMP3 be adopted as the new OMP. This CMP has ...Read more
Author:Johnston, S J; Butterworth, Doug SDate:Jan 2017Although each of the five super-areas used in the management of the West Coast rock lobster fishery is treated as homogenous in assessments, it is clear that there are inshore areas where predominantly hoops and bakkies are deployed, and ...Read more
Author:Butterworth, Doug S; Johnston, S JDate:Aug 2017OMPs have recently been accepted as the basis to recommend TACs for Tristan, Inaccessible and Gough islands. Given that for Inaccessible and Gough the recent catch rates continue to be above the associated OMP’s target catch rate, the OMPs ...Read more
Author:Johnston, S J; Butterworth, Doug SDate:May 2017The Powerboat CPUE series for Tristan was last updated in 2016 (MARAM/Tristan/2016/MAY/08) and took data for the 1994-20141 seasons into account. This GLM incorporated a method whereby the full GLM for Tristan can be rescaled to take into ...Read more
Author:Johnston, S J; Brandão, A; Butterworth, Doug SDate:May 2017The longline CPUE series for Inaccessible and Gough islands are GLMM standardised through to 20161. For Nightingale, the fishery was closed for the 2011 season and catches were set at precautionary levels for the 2011 and 2012 seasons. The ...Read more
Author:Johnston, S J; Butterworth, Doug SDate:May 2017This paper provides a further updated assessment of the rock lobster resource at Nightingale island. This assessment includes updated data from both the commercial fishery and the biomass surveys. The recent (2013-2016) high GLM standardised ...Read more
Author:Moloney, C L; Johnston, S JDate:2002Simulation models frequently are used to provide information to
assist in decision-making in natural resource management. The
sheer volume of information to process can be overwhelming,
however, and there is a danger that some management ...Read more
Author:Johnston, S J; Butterworth, Doug SDate:Jan 2017The SWG TAC recommendations for the next five years corresponded to reducing the previous recovery target by 2021 compared to 2006 from a 35% increase down to about a 7% decrease in median terms. The final DAFF decision was to leave the TAC ...Read more