Seabird interactions with trawl nets

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Final report: Seabird interactions with trawl nets (PDF, 2,290K)

Summary

The overlap of fishery operations with foraging activity over continental shelf waters in time (particularly the breeding season) and space (close to breeding colonies) results in seabird captures during commercial fishing. Seabirds are known to be caught during trawling operations as a result of hitting trawl gear such as the trawl warps (in the air and on the atwer) or becoming entangled in the net itself.

In New Zealand waters, vessels now use regulated mitigation measures in the form of seabird deterrents to minimise warp strikes in tandem with voluntary offal management regimes aimed at controlling any discharge or discarding at times when seabirds are less vulnerable.

Comments written by Ministry of Fisheries observers during their placements on commercial fishing trawlers in New Zealand waters were used to identify seabird captures that were likely to be a result of direct interaction with the trawl net.

Much of the available information suggested that individual vessel practices increased the likelihood of captures in the nets, with gear breakdowns the major reason for multiple captures. However on some occasions, observers noted that there appeared to be no obvious reason for capture other than the presence of the birds and the normal shooting and hauling practices.