Seals safe this grenadier season

5th March 2013

Seals are attracted to fishing vessels by the promise of an easy feed, they often chase fish in trawl nets. Unfortunately, some seals become disorientated in trawls and drown. Freezer vessels are boats that freeze fish at sea rather than bring fish home fresh. Around half of the South East Trawl blue grenadier catch is taken by freezer vessels. Seals are protected under the EPBC Act, it is not illegal for a fishing vessel to accidently have an interaction with a seal provided the fishery is a certified Wildlife Trade Operation (WTO) and vessels take reasonable steps to avoid interactions.
There are three phases of a fishing operation; shooting (deploying the trawl),fishing and hauling. Seals are only vulnerable when the net is near the surface during shooting and hauling. Before shooting, the net mouth is tied closed with light twine. Only when it is well underwater (too deep for seals to reach), does the spreading force of trawl doors (large metal plates used to open the net) break the twine and the net opens and begins fishing. During fishing the net is too deep for seals to reach. A seal exclusion device or SED helps protect seals during hauling. A SED is a device that allows seals to escape before they reach the cod-end (see image). SED’s are a legal requirement on freezer vessels operating in the winter blue grenadier fishery. The use of SED’s and tying the trawl mouth closed as it is shot have contributed to a significant reduction in seal interactions.