Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a
Following recommendations made at IWC 65a, 2013, a single-stock BSD (Breeding Stock D, West Australia) model has been run for a range of Antarctic catch boundaries, and some two-stock BSE1 (Breeding Stock E1, East Australia)+BSO (Breeding Stock Oceania) models have been explored. The single-stock BS...
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ftunivcapetownir:oai:localhost:11427/17837 2023-05-15T13:32:17+02:00 Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a Ross-Gillespie, Andrea Butterworth, Doug S Johnston, Susan J 2014 application/pdf http://hdl.handle.net/11427/17837 https://open.uct.ac.za/bitstream/11427/17837/1/Ross_Gillespie_Assessment_results_for_2014.pdf eng eng University of Cape Town Faculty of Science Marine Resource Assessment and Management Group http://hdl.handle.net/11427/17837 https://open.uct.ac.za/bitstream/11427/17837/1/Ross_Gillespie_Assessment_results_for_2014.pdf humpback breeding stocks Working Paper 2014 ftunivcapetownir 2022-09-13T05:53:24Z Following recommendations made at IWC 65a, 2013, a single-stock BSD (Breeding Stock D, West Australia) model has been run for a range of Antarctic catch boundaries, and some two-stock BSE1 (Breeding Stock E1, East Australia)+BSO (Breeding Stock Oceania) models have been explored. The single-stock BSD model excluded the Hedley et al. (2011) absolute abundance estimate from the model fits, and instead utilised an uninformative uniform prior on the log of the target abundance estimate. The minimum value for this prior was based on calculations by Hedley of a minimum absolute abundance indicated by the 2005-2008 survey (Hedley et al. 2011). These changes markedly improve the fit to the BSD relative abundance series. The two-stock models considered consist of one model with fixed Antarctic boundaries that allowed for a proportion of each of the BSE1 and BSO stocks to feed in a common feeding ground between 170°E and 170°W, and a second model in which there was no overlap between the two stocks, but a range of different Antarctic catch boundaries have been explored. Results of these models showed that (a) the BSE1 growth rate remained virtually at 0.106 yr-1 (the demographic boundary imposed by the model), (b) fits to the BSE1 mark-recapture data were relatively poor and (c) the Nmin constraint remained problematic for BSO. Further two-stock runs, as well as a three-stock run, have not been included in this paper, but the authors aim to provide the results as an addendum to this paper at the meeting. Report Antarc* Antarctic University of Cape Town: OpenUCT Antarctic |
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Open Polar |
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University of Cape Town: OpenUCT |
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ftunivcapetownir |
language |
English |
topic |
humpback breeding stocks |
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humpback breeding stocks Ross-Gillespie, Andrea Butterworth, Doug S Johnston, Susan J Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
topic_facet |
humpback breeding stocks |
description |
Following recommendations made at IWC 65a, 2013, a single-stock BSD (Breeding Stock D, West Australia) model has been run for a range of Antarctic catch boundaries, and some two-stock BSE1 (Breeding Stock E1, East Australia)+BSO (Breeding Stock Oceania) models have been explored. The single-stock BSD model excluded the Hedley et al. (2011) absolute abundance estimate from the model fits, and instead utilised an uninformative uniform prior on the log of the target abundance estimate. The minimum value for this prior was based on calculations by Hedley of a minimum absolute abundance indicated by the 2005-2008 survey (Hedley et al. 2011). These changes markedly improve the fit to the BSD relative abundance series. The two-stock models considered consist of one model with fixed Antarctic boundaries that allowed for a proportion of each of the BSE1 and BSO stocks to feed in a common feeding ground between 170°E and 170°W, and a second model in which there was no overlap between the two stocks, but a range of different Antarctic catch boundaries have been explored. Results of these models showed that (a) the BSE1 growth rate remained virtually at 0.106 yr-1 (the demographic boundary imposed by the model), (b) fits to the BSE1 mark-recapture data were relatively poor and (c) the Nmin constraint remained problematic for BSO. Further two-stock runs, as well as a three-stock run, have not been included in this paper, but the authors aim to provide the results as an addendum to this paper at the meeting. |
format |
Report |
author |
Ross-Gillespie, Andrea Butterworth, Doug S Johnston, Susan J |
author_facet |
Ross-Gillespie, Andrea Butterworth, Doug S Johnston, Susan J |
author_sort |
Ross-Gillespie, Andrea |
title |
Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
title_short |
Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
title_full |
Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
title_fullStr |
Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
title_full_unstemmed |
Assessment results for humpback breeding stocks D, E1 and Oceania following recommendations from SC 65a |
title_sort |
assessment results for humpback breeding stocks d, e1 and oceania following recommendations from sc 65a |
publisher |
University of Cape Town |
publishDate |
2014 |
url |
http://hdl.handle.net/11427/17837 https://open.uct.ac.za/bitstream/11427/17837/1/Ross_Gillespie_Assessment_results_for_2014.pdf |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/11427/17837 https://open.uct.ac.za/bitstream/11427/17837/1/Ross_Gillespie_Assessment_results_for_2014.pdf |
_version_ |
1766025645047939072 |