Salmon farmers will try to artificially boost oxygen levels in a depleted Tasmanian harbour but there’s no word on calls for them to destock to help save an ancient species.
The Maugean Skate is barely hanging on in Macquarie Harbour and scientists have warned it could be one extreme weather event away from extinction.
Recent conservation advice released by the federal government made it clear salmon farming was the primary human activity contributing to the Maugean Skate’s biggest threat: poor water quality.
It called for urgent action before summer to address low oxygen levels and said destocking fish pens was the fastest way to achieve that, with mechanical solutions an “and/or” remedy.
On Sept. 29, Salmon Tasmania said fish producers would pursue a potential engineering solution.
It made no mention of destocking.
The trial will use a barge and pumps to suck water from the sea, inject it with oxygen bubbles and release it into deep sections of the harbour.
Salmon Tasmania said the $6 million (US$3.9 million), two-year project would be partially paid for by the Fisheries Research and Development Corporation, which is co-funded by the federal government.
The trial is due to begin this summer.
The University of Tasmania’s Institute for Marine and Antarctic Studies will assess if it’s a feasible solution.
Salmon Tasmania CEO Luke Martin said the technology was in use successfully around the world.
“At a minimum, we aim to offset the total oxygen drawdown of our own salmon aquaculture activities in the harbour, and further reduce the impact of our operations on the environment,” Mr. Martin said.
Mr. Martin said the project was a sensible, science-based response to managing risks to the skate, in contrast to “alarmist calls to remove aquaculture from the harbour.”
“It is only because the industry is in the harbour, we can resource and activate a major response like this using proven technology to improve the marine environment for the skate.”
The Bob Brown Foundation ridiculed the announcement.
“This is like BP saying they are taking the lead in cleaning up Deepwater Horizon and everyone should be thankful,” the foundation’s marine campaigner Alistair Allan said.
“It completely ignores the fact that if fish farms were never in the harbour in the first place, the Maugean Skate wouldn’t be on the edge of extinction.”
Federal Environment Minister Tanya Plibersek says the trial is a welcome step from the salmon farming industry but the skate needed immediate help.
“That’s why I announced $2.15 million (US$1.4 million) to establish a captive breeding program to create an insurance population of Maugean Skates while we work on restoring the health of Macquarie Harbour,” Ms. Plibersek said on Sept. 29.
