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Providing evidence to improve practice

Individual study: Effectiveness of shark liver oil at deterring seabirds from attending fishing vessels in the Hauraki Gulf and off the coast of Kaikoura, New Zealand

Published source details

Norden W.S. & Pierre J.P. (2007) Exploiting sensory ecology to reduce seabird by-catch. Emu, 107, 38-43


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use shark liver oil to reduce seabird bycatch Bird Conservation

One replicated, controlled experiment off Kaikoura, South Island, New Zealand, in 2005 (Norden & Pierre 2007) found no significant differences in the number of seabirds following a bait-laying boat when it was dripping shark liver oil (both commercially available and made by fishermen) behind the boat, compared to control conditions. However, a second trial in April 2006 off Hauraki Gulf, North Island, New Zealand found the number of seabirds following a bait-laying boat decreased significantly faster if fisherman-produced shark liver oil was dripped behind the boat, compared to controls dripping seawater. Other fish oils (anchovy, pollock and commercially available shark liver oil) did not have a significant impact on the number of following birds. However, all oils except for anchovy did significantly reduce the number of dives made by seabirds.