Results 1 to 10 of about 147 (109)
Candidate Management Procedures Projections for the South African hake resource
, 2023 Results for a series of target-based Candidate Management Procedures (CMPs) under the Reference Set (RS) of Operating Models for hake are compared. The aspects and options compared are: the maximum TAC decrease constraint; the period over which abundance index averages are obtained; constant future catches; a maximum cap on the TAC; and the relative ...
Rademeyer, Rebecca A, Butterworth, Doug
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Further projections under the Reference Set for the South African hake resource
, 2021 OMP-2014 projections for the Reference Set are considered for variants which impose a further 5 000 or 10 000 ton TAC reduction for 2018 for comparison to performance under the unadjusted OMP. These reduce the number of further years for which a TAC decrease can be expected, but M. paradoxus reaches BMSY only one year earlier.
Rademeyer, Rebecca A, Butterworth, Doug
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Proposed Reference Set for the South African hake resource
, 2022 This document identifies three aspects that have been found to account for most of the uncertainty regarding the key considerations of resource status and productivity: a) pre-1978 species split of the offshore trawl catches; b) natural mortality-at-age specifications; and c) the stock-recruitment relationship.
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, 2022 An initial update of the Reference Case for the hake assessment is developed using the data available to date. This update is used to explore projections under OMP2014 and some variants thereof, with results compared to those at the time that this OMP was selected. Recent poor recruitments for both M. paradoxus and M.
Rademeyer, Rebecca A, Butterworth, Doug
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, 2022 An initial further update of the Reference Case hake assessment is presented. This incorporates all data updates now available, and also proposes a more parsimonious model for survey selectivities. The recent spawning biomass for M. paradoxus is estimated to be higher in relative terms compared to that estimated in an earlier analysis presented in May,
Rademeyer, Rebecca A, Butterworth, Doug
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Investigating the consequences of Marine Protected Areas for the South African deep-water hake (Merluccius paradoxus) resource [PDF]
ICES Journal of Marine Science, 2008 AbstractEdwards, C. T. T., Rademeyer, R. A., Butterworth, D. S., and Plagányi, É. E. 2009. Investigating the consequences of Marine Protected Areas for the South African deep-water hake (Merluccius paradoxus) resource. – ICES Journal of Marine Science, 66: 72–81. Protected areas are often touted as important management tools to mitigate the uncertainty
Edwards, Charles T T +3 more
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, 2023 Proposals are made for a Reference Set of Operating Models for testing the 2014 Revision of the hake OMP. These start from a full cross of factors covering three major axes of uncertainty: 3 centre-years for the species preponderance change in the catch x 3 natural mortality vectors x 3 stock-recruitment relationships.
Rademeyer, Rebecca A, Butterworth, Doug
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Corrected Reference Case for the South African hake resource
, 2016 An error in the way the sex-disaggregated catch-at-length data were taken into account in the likelihood in the September RC is corrected. This makes little difference to recruitment estimates and abundance trends, but in terms of the spawning biomass at MSY, M. paradoxus is estimated to be seven percentage points lower and M.
Rademeyer, Rebecca A +1 more
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, 2013 A Reference Set (RS) of 12 scenarios was selected as the primary basis to be used to simulation test candidates for OMP-2011 (Rademeyer and Butterworth, 2010). This paper presents an update of this RS, based on updated commercial data (catches, trawl and longline length distribution and trawl CPUE), some revisions of biological parameter values, and ...
Rademeyer, Rebecca A, Butterworth, Doug
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, 2013 The effects of no future surveys on projections under the current OMP for the South African hake resource are investigated by simulation. The implications of an undetected increase in catchability with and without surveys are compared. The results indicate that while surveys cannot entirely correct for bias in the CPUE, they do ameliorate this effect ...
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