FISHERIES_2021_SEP_SWG-PEL_59 Response to some queries regarding FISHERIES_2021_JUN_SWG-PEL_41.pdf (430.95 kB)
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A response to some queries concerning the revised summary of results for the island closure experiment provided in FISHERIES/2021/JUN/SWG-PEL/41

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Responses are provided to various queries raised at the PWG meeting of 15 July concerning the results from the Island Closure Experiment reported in FISHERIES/2021/APR/SWG-PEL/41. Generally, these queries are shown to have already been addressed, or to reflect incorrect assumptions. More detail is provided of the “human integration” approach used to synthesise the results of the experiment across the different islands and response variables considered. These results appear reasonably robust to alternatives to the assumptions made in this process. In summary, results for the impact of future island closure for the two Western Cape colonies are roughly estimated to be 0% with a 95% PI of [-0.5%; +0.5%], and for the two Eastern Cape colonies to be -0.25% with a 95% PI of [-0.75%; +0.25%], where a negative value indicates that closure would improve the penguin population growth rate by the value given pa. For any other colony that was not part of the experiment, which has therefore not potentially benefitted from any impact of being closed to fishing for 50% of the time over the last decade, the estimate (combined over the islands included in the experiment) is -0.25% with a 95% PI of [-1.0%; +0.5%].

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Department of Mathematics and Applied Mathematics, University of Cape Town