A brand new Zealand-led study of young toothfish in Antarctica has discovered high densities of this highly-prized seafood in the southern Ross water.

Aquatic boffins Dr Stuart Hanchet, from NIWA, and Dr Hyun-Su Jo, from Korea, recently finished the survey that is first of Antarctic toothfish.

Dr Hanchet claims the survey that is successful the very first in a string that may monitor variety of young Antarctic toothfish into the Ross water area.

He states, “To monitor seafood abundance precisely, it is important that the studies be conducted in a managed and rigorous means. For instance, this implies utilizing the exact same fishing gear as well as the exact same bait, at exactly the same time and location each year. It’s also essential that the study is very very carefully created such that it samples the area that is main that the target populace is available.

“This study are going to be a essential monitoring device to ensure that the degree of fishing stays sustainable.”

Antarctic toothfish (Dissostichus mawsoni) are located at depths right down to 2000 metres. Fish mature at a period of 120-130 cm, & most grownups reside to an age that is average of to 24 years.

“we are taking a look at both the amount and measurements of seafood which are between five and a decade old much less than 100 cm in length”, claims Dr Hanchet. “We presently gather information that is good monitor the abundance of adult toothfish, but we do not have a similar quality of data for young seafood. These seafood would be the grownups of the next day, and also by tracking this area of the populace we could ensure that catch limitations are set during the correct degree in the long run”.

” Making use of the outcomes of the study, we are in a position to model and forecast the fish population that is future. We have to develop a number of studies with time because an individual study on it’s own informs us almost no,” claims Dr Hanchet.

The Antarctic toothfish fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) under the provisions of the Antarctic Treaty. CCAMLR sets the principles for fishing when you look at the CCAMLR Convention region, including the Ross water, and all sorts of member that is participating need to operate within these guidelines.

CCAMLR requires a precautionary way of fishing when you look at the Ross water. What this means is making careful and cautious choices if you find doubt, so the level that is overall of abundance continues to be high.

Countries fishing within the Ross water must tag a number that is certain of for clinical research, and execute biological sampling of toothfish, and also other seafood types caught as by-catch.

“Tagging information happens to be critical to developing a thorough stock assessment model for the fishery to calculate biomass and set catch limits,” claims Dr Hanchet.

brand New Zealand vessels voluntarily introduced tagging in 2001, and tagging for many CCAMLR vessels became mandatory in 2004. brand New Zealand fishery experts started assessing toothfish stocks in 2005.

The study had been a brand new Zealand-led medical share to CCAMLR. It absolutely was created by marine experts in NIWA as well as the Ministry of Agriculture and Forestry (Fisheries technology), and involved a collaboration aided by the fishing industry, which offered the working platform for the survey – the Sanford vessel San Aotea II.

The primary goal of the first toothfish study would be to establish the feasibility of developing a time-series of studies observe young toothfish within the southern Ross water making use of standardised commercial long-line fishing gear.

Fifty-nine random areas had been surveyed using long-lines, each comprising 4600 hooks, set for as much as 24 hours, within a study section of 30,000 square kilometres. They caught primarily 70–100 cm toothfish (often times over 100 people per line), in depths from 300-900 metres. The seafood caught were then calculated and sexed, with biological examples taken for further analysis back New Zealand.

The survey additionally demonstrated the feasibility of collecting examples for wider ecosystem monitoring. a lot of examples|number that is large of of muscle tissues and stomachs had been collected from Antarctic toothfish and lots of other seafood types, and will also be analysed to comprehend feeding practices and relationships along with other organisms when you look at the food chain.

The outcomes with this study are going to be presented during the next CCAMLR meeting, along with a proposal to keep the study in future years.

Background facts

• Fishing for Antarctic toothfish within the Ross water area started in 1997/8.
• The sheer number of licensed fishing vessels when you look at the Ross water is very very carefully managed by CCAMLR. In the present 2011/12 period, 18 vessels were allowed to fish, of which 15 really fished.
• The total catch restriction this year ended up being 3282 tonnes.
• Brand brand brand New Zealand’s involvement when you look at the Ross water toothfish fishery is worth NZ$20-30 million per year in export earnings.
• The brand new Zealand delegation to CCAMLR comprises officials through the Ministry of Foreign Affairs and Trade, Ministry of Agriculture and Forestry, and Department of Conservation. Representatives through the fishing industry and ecological NGOs have actually been within the brand brand New Zealand delegation in previous years.
• There are 2 toothfish species in Antarctica waters. The Antarctic toothfish is located round the Antarctic continent in Antarctic waters, together with Patagonian toothfish which catholicmatch will be discovered further north in sub-Antarctic waters. The Patagonian fish was heavily over fished by illegal vessels in the mid to late 1990s. The shares are thought to have stabilised, as well as in some instances re-built.

More info

To learn more about our work with this area, see our movie Ecosystem Effects and Mitigation associated with Toothfish Fishery , in which NIWA fisheries scientist Dr Stuart Hanchet defines the principles that are guiding CCAMLR (the meeting in the Conservation of Antarctic aquatic Life) applies towards the Antarctic toothfish fishery.

He describes measures we have been making use of to deal with the possibility aftereffects of the fishery regarding the Ross water ecosystem, and exactly how our company is developing ecosystem models to evaluate these results.

Also see our work with the Ross Sea Trophic Model, that is being undertaken to simply help us better understand the relationships that are feeding types, and just how they’ve been suffering from commercial fishing, into the Ross water. This may, in turn, enable us to better handle the toothfish fishery in the area.