The Department of Primary Industries is calling on Mandurah crabbers to report any unusual crabs you find.
Senior Management Officer Marion Massam said that immediately reporting suspected aquatic pests could help eradicate them before they take hold.
“Removing a few individuals is more feasible than trying to remove a widespread population, and would cost much less, so we need all sharp-eyed fishers to keep watch,” Ms Massam said.
“So far, the Asian paddle crab has not established in the wild anywhere in Australia and, by staying alert, recreational fishers can help prevent it becoming a marine pest here in WA.”
Ms Massam said the discovery by fishers of four of these pest crabs in the Swan River in 2012 and 2014, and one in Mandurah in 2010 provided warning signs that should not be ignored.
“An invasion of this pest crab species has already occurred in New Zealand and, given the previous reports here in WA, we need to take extra care to avoid a similar impact,” she said.
“Since its detection in Auckland in 2000, the aggressive Asian paddle crab has spread to adjacent estuaries and has also been found over 100 kilometers north in Whangarei.
“There are real fears its presence may be impacting on the local ecology after gut content analysis has shown the predatory crabs have been eating bivalve shellfish and smaller crustaceans.
“A big thanks to everyone who calls FishWatch with reports of this pest. While all but a few of those calls have been native species, please keep the reports coming on 1800 815 507.”
Read more: Crabbing hot spots of Mandurah
The Asian Paddle Crab Marine Pest Alert brochure will help crabbers to be aware of its distinguishing features, especially the sharp spines on the front of the shell between the eyes.
In contrast, the small brown native four-lobed swimming crab, which has often been mistaken for the pest, has no spines between the eyes.
Crabbers who believe they have found an Asian paddle crab, please examine it closely (if possible comparing it against the pest alert) and make a note of where you saw or caught it.
Fishers are also urged to take photos of the suspect crab, especially from above, keep the specimen and phone the FishWatch 24 hour hotline on 1800 815 507 as soon as possible.