eCite Digital Repository

Code of practice for reducing accidental mortality of dolphins in purse-seine fisheries


Ward, TM and Ivey, A and Carroll, J, Code of practice for reducing accidental mortality of dolphins in purse-seine fisheries, Marine Policy, 87 pp. 203-211. ISSN 0308-597X (2018) [Refereed Article]

Copyright Statement

Crown Copyright 2017 Published by Elsevier Ltd. All rights reserved

DOI: doi:10.1016/j.marpol.2017.10.032


Purse-seine vessels commonly interact with dolphins. The total number of dolphins accidentally killed in the world's purse-seine fisheries may be substantial, even if interaction rates are generally low. This paper describes an industry Code of Practice (CoP) that was established in Australian purse-seine fishery after an observer program detected high dolphin interaction rates that had not been reported in fishery logbooks. Key features of the CoP are search and delay procedures designed to prevent encirclements and release procedures that minimise mortalities. Extrapolation from observer data (3.9% of net sets observed), suggested that 449 dolphin encirclements and 423 mortalities occurred in 2004-05, the year before the CoP was established. A decade later, observer data suggest that annual encirclements and mortalities had been reduced by 87% and 97%, respectively. Searches were highly effective in detecting the presence of dolphins. Dolphins were not encircled in > 85% of net-sets made after searches determined that dolphins were absent from the fishing area. Opening the front of the net resulted in the successful release of all dolphins in > 86% of encirclement events. Discrepancies between interaction rates estimated from observer data and those recorded in logbooks have decreased over time. This study demonstrated that codes of practice that specify changes in fisher behaviour can be effective in mitigating the interactions of purse-seine fisheries with dolphins. The avoidance and release procedures documented in the CoP for the South Australian sardine fishery are simple and, if adopted in other purse-seine fisheries, could substantially reduce global mortality of dolphins.

Item Details

Item Type:Refereed Article
Keywords:dolphins, codes of practice, purse-seine fisheries, bycatch
Research Division:Environmental Sciences
Research Group:Environmental management
Research Field:Wildlife and habitat management
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Wild caught fin fish (excl. tuna)
UTAS Author:Ward, TM (Associate Professor Timothy Ward)
ID Code:147462
Year Published:2018
Web of Science® Times Cited:1
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2021-11-02
Last Modified:2021-12-08

Repository Staff Only: item control page