The fate of big-eye tuna, over-fished and in decline, could be decided this week when fishing nations meet to set quotas after failing last year to agree on safeguard measures for the valuable food resource.

Scientists warn that unless the catch is reduced, stocks of Thunnus obesus -- prized for sashimi in Japan and canned worldwide -- could collapse within years.

A scientific report prepared for last year's meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT) showed that numbers had plummeted to less than 20 percent of historic levels.

This was only about half what is needed to support a "maximum sustainable yield" -- the largest catch that can be taken without compromising the long-term stability of a species.

ICCAT, which groups more than 50 parties including the European Union, convenes in Majorca, Spain, on Monday for another review of the situation in the Atlantic and the Mediterranean, having failed last year to agree quotas or how to include all members in the system.

Previously, ICCAT has a headline quota of 65,000 tonnes, but in practice the catch was nearer to 80,000 tonnes, well into the danger zone, according to NGOs.

The EU on Monday proposed a quota of 62,500 tonnes through to 2022 which would include 17 countries currently catching more than 1,250 tonnes a year.

Ivory Coast, Gabon, Ghana and Guinea Bissau, meanwhile, back a quota of 57,500 to 60,000 tonnes, while the Latin American states of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama and Mexico are pressing for no change.

- Quota key to recovery -

For the Pew Charitable Trusts, "a quota of 60,000 tonnes would be too high," fisheries expert Grantly Galland told AFP, suggesting 50,000 tonnes instead.

A quota of 60,000 tonnes would make the stock recovery period "too long," Galland said.

Some experts have calculated that cutting the total catch to 50,000 tonnes per year would give bigeye tuna a 70 percent chance of recovery by 2028.

ICCAT will also be looking at other species at risk -- albacore tuna and sharks.

For albacore, it suggests a quota of 110,000 tonnes from 2020.

For its part, the World Wide Fund for Nature recommends that no-go zones be established for certain periods so as to reduce the number of juvenile tuna caught.

The International Pole and Line Foundation (IPNLF), which promotes artisanal line fishing for tuna, wants the meeting to take on board the special concerns of developing coastal countries.

As for sharks, which have suffered massive human predation, Senegal is pushing for all shortfin mako sharks caught to be released, dead or alive.

The shortfin mako, also known as the blue pointer or bonito shark, is among the most at risk and is already protected under international trade by the wild fauna and flora CITES convention aimed at controlling trafficking in endangered species.

Efforts to preserve endangered Hawaiian duck's genetic diversity working, study finds
Washington (UPI) Nov 18, 2019 - An analysis suggests the genetic diversity of an endangered duck species in Hawaii has benefited from conservation efforts aimed at protecting the native bird.

The koloa is the only endemic duck still living on the main Hawaiian Islands, but decades of interbreeding feral mallards threatened to erase the duck's genetic heritage.

New research, however, showed the koloa's genetic diversity is greater than expected. The findings, published Monday in the journal Molecular Ecology, suggests conservation efforts aimed at protect the endangered duck are working.

"The fact that the koloa on Kauai are pure and have a lot of genetic variation are two really positive things that came out of this study," lead study author Caitlin Wells, a research scientist at Colorado State University, said in a news release.

Wells, who described the koloa as a "petite, buffy brown and charismatic duck," conducted the research while a postdoctoral scholar at the University of California, Davis.

Though scientists found only hybrids and feral mallards on many of the islands where the koloa used to reign, researchers documented a large koloa population on Kauai, the oldest of Hawaii's main islands. Scientists found very few hybrids living on Kauai.

Though once abundant throughout the islands, habitat loss, predation by invasive species and unregulated hunting left the koloa relegated to Kauai and Niihau by the end of the 1960s. Efforts to reintroduce the duck via captive breeding programs were compromised by hybridization with feral mallards.

For the new study, scientists collected and analyzed genetic samples from 425 koloa, mallards and hybrids from the main Hawaiian islands.

Though researchers found the endangered species' genetic diversity is high, hybridization remains prominent on three of the four main islands. Previously, scientists theorized that breeding programs would eventually dilute mallard to DNA to the point of disappearance.

"That's not what we found," Wells said. "If you don't have pure koloa parents that outnumber the feral mallards, you're not going to get any decreases in those hybrid proportions."

Still, the new research suggests conservation programs are working to preserve the species.

"Its recovery could be viewed as a beacon of hope for the many dozens of critically endangered birds found in the islands," said study co-author Andy Engilis, curator of the UC Davis Museum of Wildlife and Fish Biology.

Wells estimates tweaks can be made to conservation efforts to reintroduce and protect the DNA of pure koloas on islands besides Kauai.

"But here's a case where we have enough individuals with enough genetic variation in the koloa, and we've also genetically identified the hybridizing species," Wells said. "It seems very clear that we can separate those going forward."

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National parks a boost to mental health worth trillions: study
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