This article is more than 6 years old

This article is more than 6 years old

Five of the 11 most commonly eaten species of fish in Australia, including shark and snapper, are unsustainably managed and should be avoided by consumers, a new analysis has found.

A study of Australia’s 11 most popular types of seafood identifies imported prawns, squid and octopus, blue grenadier, shark (sold as flake) and snapper as seafood the public should avoid.

The Australian Marine Conservation Society’s sustainable seafood guide, which has been periodically updated since 2006, lists Atlantic salmon as the most popular fish among Australian diners, followed by imported prawns and then Australian prawns.

Three of the top five most popular fish are marked red in the AMCS traffic light system, meaning the organisation strongly recommends avoiding them.

The sustainability guide rates fish by a number of criteria, including how abundant they are, the impact of fishing equipment on the marine environment, management of fisheries and whether catching the species involves the inadvertent deaths of creatures such as dolphins and turtles.

The marine campaigns officer at AMCS, Tooni Mahto, told Guardian Australia there was a key trend towards farmed fish rather than those caught wild.

“More and more of the seafood on our shelves comes from farming operations,” she said. “Atlantic salmon, barramundi and prawns are all very popular farmed species.

“Overall, there have been significant improvements in farming and the industry is improving its transparency due to the fact more people care about where their seafood comes from. So we’d applaud them on that.

“But there is still a lot of work to do. It still takes 2.5kg of wild-caught fish, to be used as fish food, to create 1kg of farmed fish. It’s also hard to tell what the long-term impact of fish farming is on the marine environment.”

Mahto said at-risk species needed to be identified to help industry and consumers make better choices. “We hear a lot from the Australian government that all our fisheries are sustainable but it’s not fair to say that,” she said. “We’ve got really significant issues in fisheries, especially with bycatch.

She said Australians loved shark, “but globally 25% of shark and ray species are threatened by extinction so our consumption of shark meat is propping up this decline”.

“As an apex predator, sharks are crucial to the health of our oceans and we are still killing a lot of them with zero understanding of the impact that will have.

“Snapper is a victim on its own popularity on Australian tables, unfortunately. It needs strong management but because it’s so popular it has been hard to do that.”

Mahto said species imported from southeast Asia also posed ethical concerns, with prawn farming linked to pollution and destructive trawl fishing of squid and octopus blamed for damage to coral reefs.

Fish given the green light by ACMS include farmed barramundi, yellow fin bream, Spanish mackerel, Australian-farmed prawns and King George whiting.

“Australians need to look at their choice of seafood now, if we are to provide the next generation with the fantastic choice of fish we currently have,” Mahto said.

• This article was amended on 15 July 2014. The picture has been replaced.