Results 261 to 270 of about 132,518 (295)
Some of the next articles are maybe not open access.
2007
Updated assessments of the four orange roughy aggregations off Namibia, based upon a maximum penalised likelihood approach which uses all available indices of abundance and reflects the proportion of a stock present at the fishing aggregation each year, are presented, and projections under constant catch levels reported.
Brandão, Anabela, Butterworth, Doug S
openaire +1 more source
Updated assessments of the four orange roughy aggregations off Namibia, based upon a maximum penalised likelihood approach which uses all available indices of abundance and reflects the proportion of a stock present at the fishing aggregation each year, are presented, and projections under constant catch levels reported.
Brandão, Anabela, Butterworth, Doug S
openaire +1 more source
2004
The South African horse mackerel (Trachurus trachurus capensis) fishery began in 1950. It currently consists of a demersal/midwater trawl fleet (concentrated on the South coast) and a pelagic purse-seine fishery (concentrated on the West Coast). Adult horse mackerel are taken as a by-catch by the demersal trawl fleet and as a targeted catch by the ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
The South African horse mackerel (Trachurus trachurus capensis) fishery began in 1950. It currently consists of a demersal/midwater trawl fleet (concentrated on the South coast) and a pelagic purse-seine fishery (concentrated on the West Coast). Adult horse mackerel are taken as a by-catch by the demersal trawl fleet and as a targeted catch by the ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
2011
An age-structured production model (ASPM) is used to assess the Carpenter resource off the south western coast of South Africa. The model is fitted to standardized CPUE and length frequency linefish data. Problems encountered when attempting to fit the model to these data are explored.
Geromont, Helena F, Butterworth, Doug S
openaire +1 more source
An age-structured production model (ASPM) is used to assess the Carpenter resource off the south western coast of South Africa. The model is fitted to standardized CPUE and length frequency linefish data. Problems encountered when attempting to fit the model to these data are explored.
Geromont, Helena F, Butterworth, Doug S
openaire +1 more source
2008
Preliminary results of the sex- and area-specific age-structured production model for the South Coast rock lobster, as described in Johnston and Butterworth (2008) are presented here. The model explored to date incorporating time-varying selectivity with estimation in terms of the “MARAM” method (as reported in Johnston and Butterworth 2007).
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
Preliminary results of the sex- and area-specific age-structured production model for the South Coast rock lobster, as described in Johnston and Butterworth (2008) are presented here. The model explored to date incorporating time-varying selectivity with estimation in terms of the “MARAM” method (as reported in Johnston and Butterworth 2007).
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
2020
An Age-Structured Production Model is applied to assess the Alfonsino (Beryx splendens) resource in the West and East SIOFA areas of the Southern Indian Ocean. Data limitations restrict these applications to deterministic variants, which assume no variation in annual recruitment about the predictions from a stock-recruitment relationship.
Brandão, Anabela +2 more
openaire +1 more source
An Age-Structured Production Model is applied to assess the Alfonsino (Beryx splendens) resource in the West and East SIOFA areas of the Southern Indian Ocean. Data limitations restrict these applications to deterministic variants, which assume no variation in annual recruitment about the predictions from a stock-recruitment relationship.
Brandão, Anabela +2 more
openaire +1 more source
2007
The conventional ASPM assessment of the South African horse mackerel resource is updated by taking account of recent trawl survey results. Projections are similar to those of previous assessments: a demersal/deepwater catch of 44 000 tons pa can be increased only provided the annual pelagic catch is kept below 5000 tons, or if the swept area survey ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
The conventional ASPM assessment of the South African horse mackerel resource is updated by taking account of recent trawl survey results. Projections are similar to those of previous assessments: a demersal/deepwater catch of 44 000 tons pa can be increased only provided the annual pelagic catch is kept below 5000 tons, or if the swept area survey ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
2008
This document provides an update on the development of sex- and area-specific operating models for testing candidate OMPs for the South Coast rock lobster resource. Models are needed which can provide reasonable fits to both the CPUE and catch-at-length data available.
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
This document provides an update on the development of sex- and area-specific operating models for testing candidate OMPs for the South Coast rock lobster resource. Models are needed which can provide reasonable fits to both the CPUE and catch-at-length data available.
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
2008
A Reference Case application of ASPM to the Georges Bank yellowtail flounder, together with three sensitivies, is presented. Strong residual patterns in the fits to survey indices of abundance, particularly to that for the Canadian DFO Spring survey, raise concerns about the compatibility of the population model and these indices.
Butterworth, Doug S +1 more
openaire +1 more source
A Reference Case application of ASPM to the Georges Bank yellowtail flounder, together with three sensitivies, is presented. Strong residual patterns in the fits to survey indices of abundance, particularly to that for the Canadian DFO Spring survey, raise concerns about the compatibility of the population model and these indices.
Butterworth, Doug S +1 more
openaire +1 more source
2006
The assessment conducted in 2006 has been routinely extended, taking account of a further year’s catch, CPUE and catch-at-age data. CPUE shows a continuation of the increase that commenced in 1998. The sustainable yield estimates are generally very similar to those for the 2005 assessment, although estimates of current biomass levels relative to K ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
The assessment conducted in 2006 has been routinely extended, taking account of a further year’s catch, CPUE and catch-at-age data. CPUE shows a continuation of the increase that commenced in 1998. The sustainable yield estimates are generally very similar to those for the 2005 assessment, although estimates of current biomass levels relative to K ...
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
2005
The 2005 assessment was routinely extended, taking account of a further year’s catch, CPUE and catch-at-age data. CPUE shows a continuation of the increase that commenced in 1998. However, sustainable yield estimates are generally less than those for the 2004 assessment, although estimates of current biomass levels relative to K increase. The Reference
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source
The 2005 assessment was routinely extended, taking account of a further year’s catch, CPUE and catch-at-age data. CPUE shows a continuation of the increase that commenced in 1998. However, sustainable yield estimates are generally less than those for the 2004 assessment, although estimates of current biomass levels relative to K increase. The Reference
Johnston, Susan J, Butterworth, Doug S
openaire +1 more source