Planting hope for handfish survival
A NEW project is creating renewed hope for the survival of Tasmania’s endangered red handfish, as researchers busily undertake a trial to restore the species’ habitat.
Researchers at the Institute for Marine and Antarctic Studies (IMAS) are ‘sea gardening’, to increase the amount of seaweed for the handfish to live in.
“Red handfish are literally running out of habitat,” marine biologist Jemina StuartSmith said.
“We’re trying to restore lost habitat by translocating
seaweed-covered boulders to areas that have been decimated by an increase in native urchins.
“Seaweed provides shelter and structure for handfish to lay their eggs on.”
Dr Stuart-Smith said urchins had overgrazed areas making them unsuitable for red handfish to live in.
“The urchins are like pests that come into the garden and eat the vegetables,” she said.
“It’s likely that removal of natural urchin predators from the area, including large lobsters, is one of the factors causing an increase in urchin
numbers. We’re essentially planting advanced ‘shrubs’ in our garden and trying to remove the pests at the same time.”
The trial is at an early stage, but Dr Stuart-Smith said the sea-gardening, in combination with efforts to remove urchins, looked promising.
“We’re hoping to know mid-year, but we think the seaweed is surviving and, assuming we can keep on top of urchin numbers, we’ll be able to increase the amount of habitat available to the handfish,” she said.
Since 2018, the team has conducted three urchin removals,
with the help of the Tasmanian Commercial Divers Association.
“Urchin fishers removed 12,000 urchins in one day, and we’ve removed around 30,000 urchins in total from our small sites.”
The sea-gardening project has been made possible by funding from NRM South.
“The current wild red handfish population estimate is 100 adults; they’re on the brink of extinction,” Dr Stuart-Smith said.
“We’re making really good ground with growing the handfish in captivity, there’s no point doing that unless
they have something to go back to.”
Dr Stuart-Smith said while promising, more work would be needed to save the red handfish.
“It’s really a Band-Aid solution, the goal moving forward is we need habitat in the area for the handfish,” Dr Stuart-Smith said.
“The long-term solution is to restore ecosystem balance.”
Dr Stuart-Smith is presenting research at the International Temperate Reefs Symposium in Hobart, which runs until January 12.