At least four species of shark and skates unique to Australia are at an extreme risk of extinction unless urgent protections are put in place, according to a new report from conservationists.
All four species – the whitefin swellshark, Sydney skate, grey skate and greeneye spurdog – spend their lives on the ocean floor but get caught in trawl nets.
Analysis of decades of fisheries data, combined with knowledge of the biology, suggests these four animals are at an extreme risk of extinction.
A further six deep-sea sharks are also considered to be declining, with a need for protection.
“It’s time that these species got a look in,” said Dr Leonardo Guida, a shark scientist and campaigner at the Australian Marine Conservation Society (AMCS). “For too long a lot of these deep-water species have been ignored.”
“Australia really is a hotspot of shark and ray biodiversity. We have more than 320 species and more than half of those are found nowhere else on the planet.
“But if these species go extinct then that is a global extinction. When you look at their evolutionary history, it is 400 million years old. If we can’t save them, no one else can.”
The report, to be released today, looked at 10 species of deep-water sharks, skates and rays that are considered by the International Union for Conservation of Nature to be threatened, but are not listed as threatened in Australia.
All 10 species had undergone “demonstrable fisheries-driven population declines that have increased their risks of extinction”, the report, commissioned by AMCS and the Humane Society International, said.
The society has nominated seven of the species to the national threatened species list.
For the most at-risk species, the report said, there were fears numbers could be so low that “populations are predicted to crash, that is fall to such low numbers that they may never recover”.
Report authors Dr Ross Daley and Prof Charles Gray recommended that bycatch reduction devices should be used that allow sharks and rays to escape through a hatch in the trawl net.
Gray said: “Getting sharks and rays recorded correctly at the species level, rather than grouped under a generic term like ‘unspecified stingray or stingaree’, is crucial because we can get a better sense of what’s being caught where and in what volumes. It’s critical if you want to have a sustainable fishery.”
Improving the knowledge of fishers and observers to better identify the species they catch was also essential.
Other moves that could stop the species going extinct were closing areas for fishing, declaring some species as “no take”, and improving the handling of the animals once caught so they had a better chance of survival if released.
Some of the sharks caught in trawl nets were not discarded but kept for consumption, Guida said.
The Guardian asked the assistant minister for forestry and fisheries, Senator Jonno Duniam, what the federal government would do to protect the species and if it would look at and of the report’s recommendations.
Duniam said in a statement: “Australia is a world leader in fisheries management, and the harvest of commercially targeted shark species in commonwealth fisheries is sustainable.
“Our government has a range of management measures to mitigate fishing impacts on non-targeted species.
“Consumers can be confident when buying Australian seafood that they are choosing high-quality fish from well-managed and sustainable Australian fisheries.”