Scientist heads south to study toothfish

00:00, Jan 21 2013

A fisheries scientist from Nelson is heading to Antarctica to board a fishing vessel in the Ross Sea amid continuing debates over how the marine ecosystem should be managed.

Dr Steve Parker, of the National Institute of Water and Atmospheric Research, will fly to Scott Base on Ross Island this week with a Spanish colleague.

The pair will board a New Zealand fishing vessel from Cape Bird, about a 20-minute flight from Scott Base, and spend just over two weeks surveying juvenile antarctic toothfish in the southern Ross Sea region.

The survey is targeting young antarctic toothfish aged between five and 10 years old, and is sponsored by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the Ministry for Primary Industries, and fishing company Sanford.

It fits into the wider context of the Ross Sea marine ecosystem and debates over how it should be managed.

New Zealand and the United States have put forward a joint Ross Sea protection proposal for consideration by CCAMLR at a meeting in Germany in July, but advocates including United States Antarctic ecologist Dr David Ainley say the region should be protected from fishing altogether.


The Antarctic Ocean Alliance (AOA) is calling on Prime Minister John Key, who is in Antarctica, to make a personal commitment to securing a marine reserve in the Ross Sea this year and to increase the level of protection the proposal offers.

Dr Parker said each fishing vessel in the Ross Sea already had two observers on board, one from the vessel's country of origin and an international observer from another country.

The observers collected data on the size and weight of toothfish caught, as well as information on other species encountered.

Fishing vessels usually only targeted adult toothfish, which entered the fishery at about 10 years old, and little was known about the juvenile population.

Dr Parker said information on how large or small the juvenile population was could be fed into stock assessments used to adapt catch limits.

The survey would bring in about 2000 juvenile toothfish, which were usually found in shallower waters - 500 to 800 metres - and data such as size, sex, age and diet would be recorded.

Most of the fish would be kept by the fishing company, but five in every tonne would be tagged and released so researchers could track their movements.

"The real value in these surveys is that we do the same thing every year, with really standardised gear. Among other things, the scientists pick the locations, the type of hooks used, and how long to fish for."

Dr Parker said New Zealand started fishing for antarctic toothfish in 1997, and had since been joined by other nations.

"The research is ramping up in different ways. We have had an active research programme since the fishery started, but there are now a lot more information demands - such as monitoring the ecosystem," he said.

"What we want to be able to do is to look into the future a bit more by understanding the juveniles - the adults of tomorrow. You continue to learn as you go, and a lot of that information has come from the fishery itself."

Dr Parker said the number of spawning adults was used to measure the toothfish population, and the pre-1997 "unfished stock" was recently estimated to be near 75,000 tonnes.

This had been reduced to about 60,000 tonnes, based on a 2011 stock assessment. The total catch limit for all nations for this season, set by CCAMLR, was 3282 tonnes.

The Nelson Mail