Aspects of the biology of fishes in the Ross Sea toothfish fishery
Project: Aspects of the biology of fishes in the Ross Sea toothfish fishery
Project Code: ANT2004/02
Start Date: 1 October 2004
Completion Date: 30 September 2005
Vessel Use: None
Overall Objectives:
- To further explore the biology of fishes captured in the Ross Sea toothfish fishery.
Specific Objectives:
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To describe aspects of the biology of toothfish in the Ross Sea.
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To describe aspects of the biology of rattails in the Ross Sea.
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To describe aspects of the biology of skates in the Ross Sea.
Note:
The final scope of this project and the specific objectives will be determined after the October 2004 meeting of the CCAMLR Working Group on Fish Stock Assessment (WG-FSA).
Depending on the extent of activity by New Zealand fishers in the 2004-05 summer, some of the specific objectives may need to focus on CCAMLR areas other than the Ross Sea.
Rationale:
General
Toothfish are the major finfish resource currently exploited in the Southern Ocean, with only krill exceeding the catch in recent years. There are two species of toothfish, both with a circumpolar distribution.
Patagonian toothfish D. eleginoides are generally found north of 65° S and Antarctic toothfish D. mawsoni generally south of 65° S, although there is overlap in some areas, notably in the northern Ross Sea, on the South Orkney/Antarctic Peninsula and on the southern Kerguelen Plateau. The fishery in Antarctic waters is managed through the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).
Longline and trawl fisheries have begun and continue to be developed by the United Kingdom, France, Australia, New Zealand, South Africa and others both inside EEZ waters and in other CCAMLR waters. In recent years, permits have been approved for New Zealand companies to fish in the Ross Sea (CCAMLR sub-area 88.1 and sub-area 88.2). In more southerly waters, D. mawsoni forms a greater proportion of the catch.
CCAMLR has previously recommended a number of research priorities for toothfish to be undertaken by member countries; these focus on the provision of accurate catch and effort statistics, target and non-target species biology, fishery/ecosystem interaction issues and estimating productivity and abundance of the target stocks.
The project will depend on co-operation of the New Zealand industry and on international collaboration, and will integrate with projects carried out by other CCAMLR member countries. This integration and co-ordination is undertaken by the Ministry of Fisheries Science Group and does not form a part of this research programme.
Objectives 1, 2 & 3
The biology of the fishes captured in the Ross Sea has been explored in some detail, but additional research is still required.
For toothfish, age and growth are moderately well known, and stock structure and feeding are currently being explored. Additional research into movement, spawning and feeding is required.
For rattails, age and growth have been explored. An understanding of feeding, age at maturity, age validation and diet are the next priorities.
For skates, initial methods for ageing are being explored. Further ageing work, revision of estimates of age at maturity, species identification guides, description of movement patterns and an understanding of feeding is required. One key output of this programme will be improved identification guides for observers.
Strategic Relevance
The Ross Sea fishery is an exploratory fishery. CCAMLR expects research in exploratory fisheries to be conducted to meet management requirements. This project directly meets CCAMLR management requirements.
All the objectives in this project are consistent with the Antarctic Fisheries Medium Term Research Plan and the Strategic Framework and Directions for Fisheries research Contracted by the Ministry of Fisheries document.
Cost Recovery Information:
This project is 100% Crown funded.
The project is estimated to cost between $100,000 - $150,000.