Urchins Threaten Abalone Population

Acting Executive Director of Fisheries Victoria, Travis Dowling said in recent years black sea urchins (Centrostephanus rodgersii) had expanded their range and increased in abundance in southern NSW, eastern Victoria and Tasmania.

This increase is believed to be climate change related and due to a strengthening East Australian Current since the 1950’s.

“Black sea urchins are voracious predators, feeding on macro-algae and can clear whole sections of reef, which then become urchin barrens,” Mr Dowling said.

“This can lead to a reduced abundance and productivity of abalone populations and other reef species.

“Southern Australia is home to one of the worlds last sustainable abalone fisheries.

“It is hoped that reducing urchin biomass on barrens will lead to a restoration of macro-algal communities, improvements in abalone abundance and better quality urchin roe among remaining urchins.

“The quality of urchin roe is reduced in these barrens, resulting in an unproductive urchin fishery as well.

“So an urchin biomass reduction trial is to start shortly, to evaluate the effectiveness of reducing urchin numbers in recovering abalone habitat on previously productive reefs in eastern Victoria.

“This project is a joint initiative between the Eastern Zone Abalone Industry Association and the Department of Primary Industries and will run for three years.

“It is hoped the project will allow us to recover the biodiversity of reefs that have been impacted by urchins and thereby maximising the productivity of both the abalone and urchin fisheries.”

Geoff Ellis, Executive Officer of the both the Eastern Victorian Sea Urchin Divers Association and the Eastern Zone Abalone Industry Association said the partnership with the Department would ensure sustainable, abundant and viable stocks of both abalone and sea urchins.

“If the project is successful divers will continue to maintain urchin populations as part of their commercial diving activities,” Mr Ellis said.

The number of urchins being removed represents only a small fraction of the overall population in east Gippsland.