Kahawai
Seafood with Concerns
Scientific name: Arripis trutta
Other names: koopuuhuri, kooukauka
(Maori), Australian salmon (Australia)
Ranking: D (Amber - Concerns)
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Description: Most kahawai are caught in purse seine fisheries that also target skipjack tuna, jack mackerel and blue mackerel. A lesser proportion is caught seasonally in set net and mixed species trawl fisheries.
The main concerns with this fishery are: the uncertain maximum sustainable yield, non-target fish bycatch, the unknown status of stocks, stock structure and stock trends, the lack of a management plan, limited past research and the ecological effects of the fishery.
The fishery assessment plenary report states: For KAH1 "curent removals are lower than almost all estimates of deterministic MSY. Combining this with the result that most estimates of current biomass are well above Bmsy it is unlikely that the stock will decline below Bmsy at current assumed catch levels, given the model recruitment assumptions. For all other KAH areas: "It is not known if the current catches, allowances or TACCs are ustainable, or at a level that will allow the stock to move towards a size that will support the MSY." (MFish 2007, p 408).
Market: Exports of $2m mainly to Australia.
Status and sustainable yield
Status: While the assessment is uncertain the stock is most likely above Bmsy Ð between 27% and 69% Bo.
Annual catch limit: Set at 2,728 tonnes in 2005-06.
Recorded catch: Reported landings of 2,013 tonnes in 2005-06.
Population size: The KAH1 assessment that stock has declined to a mid-range of 43-45%Bo.
Stock trends: Unknown.
Fishing method
Method: Most are caught by purse seiners with less taken seasonally in set-net and trawl fisheries.
Habitat damage: Low impact from purse seiners and set netting; high impact from trawl fisheries on bottom dwelling species.
Bycatch: Range of other pelagic species including skipjack tuna, kingfish, blue mackerel and jack mackerel.
Ecological effects: Loss of large older fish, impact of bottom trawling bulldozing the seabed and ecological implications of set netting.
Management
Stock assessment: A new quantitative assessment in 2007.
Management plan: No.
Quota Management Species: Yes, from 1 October 2004.
Biology
Distribution: Found in inshore waters around New Zealand but most common from Kaikoura northwards.
Maximum age (years): 26
Age at sexual maturity: 5
Growth rate: Moderate to high.
Reproductive output: Medium to very high.
Age exploited: 3-4.
References: Report from the Fishery Assessment Plenary, May 2007: stock assessments and yield estimates. Part 2: Hake to Paua, Science Group, Ministry of Fisheries; Guidebook to New Zealand Commercial Fish Species, Revised Edition 1990.
This page was updated on 9 November, 2007 |
