The Antarctic toothfish is being sustainably caught in the Ross Sea and the catch is still many years away from reaching the minimum level to safeguard its viability, a leading scientist says.
Dr Stuart Hanchet, who works for NIWA, has been researching the high-value species for 15 years. He told 90 people attending a Nelson Science Society event in a packed lecture room at the Nelson Marlborough Institute of Technology on Tuesday night that the fishery was “undoubtedly contentious”.
But the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), with 25 member nations, managed the toothfish catch with “quite rigid scientific rules”.
“This is amongst the the most highly-monitored, heavily-regulated and data-rich fisheries in the world,” Hanchet said.
The toothfish catch was pioneered by New Zealand boats in the late 1990s and the fish are now targeted by a multi-national fleet of between 15 and 20 vessels each summer.
They are limited to 3000 tonnes between them, with 20-30 per cent of the total caught by New Zealand boats fishing for Sealord, Talley’s and Sanford.
CCAMLR manages the Ross Sea, an area adjoining Antarctica and almost as big as Australia.
Hanchet said the international body, which included all the major nations, had both a precautionary and an ecosystem approach to fisheries management.
Its two drawbacks were that all decisions were made by consensus, meaning a proposal for a 1 million square kilometre Marine Protected Area had stalled, and that its decisions were only binding on member countries.
This meant that there was some illegal, unregulated and unreported (IUU) toothfishing going on, but its impact on the Ross Sea fishery was considered very low. The presence of the CCAMLR-approved vessels, air and navy patrols and the dangers of fishing in the Antarctic all combined to keep the non-approved boats away.
If they did intrude, the weight of CCAMLR – “25 of the most important countries in the world” – would usually mean that the transgressor would move its boat out of the area or take steps to accede to the CCAMLR convention, Hanchet said.
“It’s not ideal, but I think most of the time it probably does work in practice. Even if you’ve got a frigate with big guns on, you can’t just go and board them – that’s piracy.”
Illegal fishing under flags of convenience was a problem in other parts of Antarctica, with five boats being found over the last season. One had sunk after allegedly being scuttled and four were currently under arrest in port, he said.
IUU fishing was not only a problem in Antarctic waters, but world-wide.
“It’s often Spanish skippers that seem to be the main players, and often Spanish companies working under second companies and third companies.”
However, CCAMLR managed the Ross Sea fishery to ensure that the toothfish population was maintained at a stable recruitment level, setting the bottom limit at 50 per cent of the virgin stock.
Using a tagging programme and a complex stock assessment model updated every two years, the scientists estimated that in 2013 the stock had declined to 80 per cent of the virgin level and that it would take 35 years at the current 3000-tonne catch limit to reach 50 per cent.
“The toothfish stock is being sustainably managed. The stock assessments are conservative and precautionary.”
He said the Antarctic toothfish, which had anti-freeze in its blood, reached 2 metres and 150 kilograms and lived for 50 years, about the same lifespan as snapper and one-third as long as orange roughy.
It was almost all caught by bottom longline with the biggest recorded single catch to date being about 50 tonnes on one 5000-hook longline.
“There was a fish on almost every single hook. It’s absolutely staggering.”
Asked why it was so high-priced, selling for $60-$70kg in the US, Hanchet said the fish had been carefully marketed in high-end restaurants, sold as Chilean sea bass and often served with a rich sauce.
“It’s a very bland, solid white flesh, very soft and tender to eat.
“It’s also incredibly oily. If you cut a toothfish fillet and put it on your plate, within a minute there’ll be a pool of oil all around it.”
The Ross Sea toothfish catch has been criticised by some conservation groups including the Last Ocean Charitable Trust, based in Christchurch. The issue got fresh traction in Nelson this month when Talley’s Group-owned Guyton’s fish shop offered frozen portions on special at $3.90, quickly selling out.