Bottom longline - Seabird interactions & accidental capture
Issue
Birds are attracted to bottom longline fishing vessels by discarded bait and offal. Some birds dive down to eat the bait from hooks; some get hooked and drown.
Risk
Evidence of bird captures from overseas and in New Zealand's bottom longline fleet suggests this may be a significant risk to seabird populations, many of which are considered threatened or endangered.
Extent of the issue
New Zealand has significant bottom longline fisheries. However, apart from the deepwater ling autoline fishery, we have poor information on seabird deaths in these fisheries (small bottom longline vessels averaged <1% observer coverage between 2002 and 2006).
Trends
The deep water ling autoline fleet has done a good job of seabird mitigation in recent years. However we know little about the performance of smaller bottom longline vessels operating around New Zealand.
Current management
Government has regulations that mean bird-scaring devices such as tori lines must be used by all vessels to keep birds away from baited hooks when the line is being set. As well as this, all longline vessels must either meet minimum line weighting requirement or else fish at night - which makes it harder for birds to see the baits.
Future management
Fishing-related risks for all New Zealand seabird species will be assessed as part of New Zealand's National Plan of Action (NPoA) to reduce seabird capture in fisheries. Treatment plans will be developed where risks are considered above 'acceptable' levels.
Documents / links
Documents around NPOA seabirds / seabird standard, Abraham & Thompson 2008, CSP research plan, CSP website
