Western Australia’s West Coast Deep Sea Crustacean Managed Fishery (WCDSCMF), which involves commercial fishers often journeying to the edge of the continental shelf, is using science to demonstrate the fishery’s ongoing sustainability.
The fishery has been certified sustainable under the Marine Stewardship Council (MSC) since 2016.
To assist in the ongoing certification of this fishery, scientists from the Department of Primary Industries and Regional Development (DPIRD) have been deploying cameras to illuminate these deep and remote locations to learn about the habitat of crustacean species like the crystal crab, also known as the snow crab due to its white shell which is highly prized in Asian and Australian seafood markets.
It’s a fishery with a long history of catching giant crabs and champagne crabs but last year a new species, the fishers refer to as the sun king crab, was landed for the first time in the northern part of the fishery.
The WCDSCMF includes waters of the Indian Ocean and Timor Sea off northern WA and is bounded by Australia’s exclusive economic zone (EEZ).
Collaboration with fishers has been vital to the research which is gathering data to confirm the sustainability status. This includes cameras monitoring onboard processing of the catch to provide stock composition data for use in periodic stock assessments.
The camera-based research has found that the fishery has very low bycatch and a low overall impact on the environment which supports maintaining its MSC certification.
The cameras capture all steps of the processing before the crabs are placed in tanks for transferring to shore and sold as live catch and is popular for display in restaurants. The much sought after crystal crabs can sell for up to $400 ($150 – $200 per kilogram) in some restaurants in Asia and Australia.
Under quota limits, there are three vessels currently operating in the fishery which land live crabs at ports between Carnarvon and Fremantle – mostly at Denham and Geraldton. The fishery’s production value in 2021/22 was approximately $6.8 million, including valuable export dollars for Australia.
DPIRD Principal Research Scientist for Offshore Crustaceans Simon de Lestang said two cameras fixed at 40 centimetres apart on the vessel record where the crab pots are hauled onboard and unloaded.
“Not only do they record video of all the crabs caught, these research cameras also record all the pots retrieved, enabling pot-by-pot calculation of catch rates, size and sex composition as well as documenting the limited amount of bycatch,” Dr de Lestang said.
“Our team has calibrated the two cameras, which allows us to use software to accurately measure each crab.”
In a separate research project, funded through MSC’s Ocean Stewardship Fund, DPIRD scientists are also using pot-based cameras and lights to illuminate the seabed and deep ocean habitat and were developed through the Commonwealth’s Fisheries Research and Development Corporation.
“To date, we’ve recorded vision at 20 locations in the fishing grounds, and the Marine Stewardship Council-funded research is helping us better understand any potential impacts of the fishing activity,” Dr de Lestang added.
A big eye ocean pearch glides past a pot camera 600 metres down
“The support of the commercial deep sea crab fishers has been important to the research project in the deployment of the pots with cameras and shipping them from Geraldton to Perth for the vision to be downloaded.
“This research has benefitted from the collaborative management approach adopted by the industry, the WA Fishing Industry Council and DPIRD.”