Invasive Asian crab caught in Swan River

Asian paddle crabs have six sharp spines between the eyes.
Asian paddle crabs have six sharp spines between the eyes.

FEARS are held for the Swan River’s marine life after an Asian paddle crab was confirmed again to have been caught in Blackwall Reach, Bicton last week.

The confirmation follows several years without reports of the paddle crab.

Fisheries now fears the pest could out-compete native species including the blue swimmer crab, after the invader successfully colonised New Zealand waters since 2000.

“So far, the Asian paddle crab has not established pest populations anywhere in Australia and, by staying alert, we can help prevent it becoming a marine pest here in WA,” Fisheries aquatic biosecurity officer Marion Massam said.

In Perth, the Asian paddle crab was initially caught in Mosman Bay, Mosman Park in 2012 and 2014, while one was found in Mandurah in 2010.

The latest confirmation came after an alert fisher caught the crab in Blackwall Reach, about 1km from Mosman Bay, before keeping it and reporting it to FishWatch

Ms Massam said continued vigilance by crabbers was vital to stop the species from establishing in the river.

“The newly discovered Asian paddle crab is brown with orange highlights and purple legs, but we know the species varies greatly in colour and its definitive features are the six sharp spines between the eyes and the six spines down each side of the shell,” she said.

The underside of the pest caught at Blackwall Reach last week.

However, the pest can be confused with natives such as the small four-lobed swimming crab, but it has no spines between its eyes.

“If you think you’ve found an Asian paddle crab, please examine it closely by comparing it against the pest alert that’s available online at www.fish.wa.gov.au, and make a note of where you saw or caught it,” Ms Massam said.

The crab identified as an Asian paddle crab on today.

A suspect crab must be photographed, especially from above, kept and the FishWatch 24 hour hotline called on 1800 815 507.

More information is at www.fish.wa.gov.au/biosecurity.