Certain species of shark that can only be found in Australian waters are close to going extinct due to commercial fishing unless something is done about it, according to a new study released this week.
The report, commissioned by the Australian Marine Conservation Society (AMCS) and Humane Society International (HSI), warns that the populations of species like the whitefin swellshark and the eastern angelshark are still declining.
Of the 322 shark species found in Australian waters, half of them don’t exist anywhere else in the world.
The report provides solutions to save these sharks and rays including listing species like whitefin swellshark as “no take” species, retaining existing fishery closures to help with recovery of species, and training fishers in species identification and safe-handling practices to help with survival rates of released animals.
AMCS shark scientist Dr Leonardo Guida said it would be a tragedy to lose these species before we even get to know them.
“As much as a koala is unique to Australia, so too are half of our sharks and rays. The whitefin swellshark is one of my favorites – when it feels threatened, it’ll swallow water to literally swell up and make itself appear bigger.
“It’s pretty heartbreaking when you realise that a minimum average of 1,300 of these quirky whitefins are harvested each year for consumption.
“Most of our endemic sharks and rays live in the deep waters on continental shelves and slopes, some as far down as 1300m. Trawlers are one of their major threats, and our deep sea dwellers are silently suffering the brunt of it.
“Many Australians don’t know about these unique characters and unless there are changes, we could lose them before we even get to know them.”
Australia’s southeastern waters, which cover southernmost Queensland through New South Wales and into eastern Victorian waters are described as an extinction-risk hotspot for the most threatened endemic sharks and rays.
The report — co-authored by Ross Daley and Charles Gray — highlights critical problems that need to be addressed in different fisheries in that region, including trawlers having inadequate or an absence of bycatch reduction devices such as “separator grids” — a device allowing sharks and rays to “bounce off” through an escape hatch in the trawl net.
The report also highlights the incorrect and inaccurate reporting of shark and ray species caught.
“Our report shows that the whitefin swellshark needs urgent help. Making it a no-take species will go a long way to bolstering its recovery. They’re a tough and resilient species, if handled right, they’ve got a good survival rate when returned to the water.”
“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.”