Fisheries Infosite

FAR 2017/12 Recalculation of historical landings of porbeagle shark.

Filename
FAR-2017-12-Porbeagle-shark-historical-landings.pdf

Link to file
FAR-2017-12-Porbeagle-shark-historical-landings.pdf (895.3 kb)

Abstract
Historical conversion factors (CFs) applied to shark fin processed weights to determine landed whole weights have sometimes been inappropriate, leading to biased estimates of fishing mortality. A new time series of New Zealand annual porbeagle shark mortality was derived using appropriate CFs and an allowance for mortality of discards and released live sharks. The revised time series resulted in 6% more mortality by weight overall for 1998โˆ’2016, with annual values varying by โ€“22% to +42%.

Document date
Friday, 17 March 2017
Document type
V 1.3
File format
Adobe PDF
File size
895.3 kb
Reference number
978-1-77665-514-4
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Uploaded from
FAR-2017-12-Porbeagle-shark-historical-landings.pdf

Uploaded date
Friday, 17 March 2017

Search tags
Author: Francis, M.P.;
ResearchField: fishing mortality; Historical conversion factors; historical landings; porbeagle shark; processed weights; shark mortality; time series;
ScienceStock: Highly migratory species;
Species: porbeagle;

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