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Seafood to Avoid
Blue sharkScientific name: Prionace glauca
Other names: mango-pounamu, poutini (Maori), blue whaler, blue pointer
Ranking: E (Red - Avoid)
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Description: Blue sharks are taken in large numbers in the tuna longline fisheries mainly in the West and East Coast of the North Island from the Bay of Plenty north. Most of the blue sharks are finned and the rest of the carcass is dumped. Jointly with Pacific bluefin tuna, Blue sharks have the third worst ecological ranking of any commercial fishery.
The main concerns are with this fishery are: uncertainty about the state of the stocks, the bycatch of other sharks, seabirds and fur seals, limited research, and the lack of a quantitative stock assessment or a management plan. Removal of this large predatory species may also have negative ecological implications.
The fishery assessment plenary report states: "For all fishstocks, it is not known if recent landings or TACCs are at levels which allow the stocks to move towards a size that will support the maximum sustainable yield." (Ministry of Fisheries, 2007, p156).
Market: Fins to east Asian markets.
Status and sustainable yield
Status: Uncertain. Listed by IUCN red list as a near threatened species.
Annual catch limit: Set at 1860 tonnes in 2004.
Recorded catch: Landings of 1223 tonnes by tuna longliners and 663 total reported catch.
Population size: South Pacific migratory population.
Stock trends: Uncertain, estimates of reference and current biomass are not available.
Fishing method
Method: :Longlining around the North Island.
Habitat damage: Low.
Bycatch: Other sharks and New Zealand fur seals are caught in the longline fishery.
Ecological effects: Removal of large predator species as bycatch in the longline fishery.
Management
Stock assessment: No quantitative stock assessment.
Management plan: No.
Quota Management Species: Yes, since 2004.
Biology
Distribution:
Maximum age (years): 22
Age at sexual maturity: 8 for males and 7 to 9 for females.
Growth rate: Slow
Reproductive output: Low.
Age exploited: 8
References: National Tuna Fishery Report 2001 Ð New Zealand, T Murray and L Griggs, NIWA; Report from the Fishery Assessment Plenary, May 2007: stock assessments and yield estimates. Part 1: Albacore to Groper., Science Group, Ministry of Fisheries; Guidebook to New Zealand Commercial Fish Species, Revised Edition 1990, NZ Fishing Industry Board.
This page was updated on 9 November, 2007 | 
