The Australia Institute Tasmania has written to federal Environment Minister Tanya Plibersek, urging her to intervene and end salmon farming in Tasmania’s Macquarie Harbour, which is threatening the endangered Maugean skate.

The letter asks the Minister to review the decision to greenlight expanded marine farming operations. The decision was made more than a decade ago under the Environment Protection and Biodiversity Conservation (EPBC) Act, on the grounds the operation would not significantly impact the species. However, new research from the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS) found evidence of a decline in the harbour’s skate population, heightening  concern about the species’ already-endangered status.

“The Environment Minister has obligations under multiple laws to act to protect the Maugean skate before it is too late,” said Eloise Carr, director of the Australia Institute Tasmania.

“Based on new evidence in the IMAS report, we have requested a review of the decision to allow expanded salmon farming operations. We think the correct decision, in light of the new evidence, would be to immediately and fully protect the Maugean skate by ceasing marine farming in Macquarie Harbour.

“If the Minister fails to act to stop salmon farming in Macquarie Harbour, we think she will be in breach of the law.

“Substantial new information in the IMAS report confirms fish farms are having a significant impact on the Maugean skate by causing a lack of oxygen in the water, pushing the Maugean skate towards extinction. Gillnetting, extreme weather and irregular dam releases are adding to the threats, as is climate change, but the underlying problem is the lack of oxygen caused by salmon farming.

“The IMAS report found evidence that the significant decline in oxygen in Macquarie Harbour waters, is linked to the development of large-scale aquaculture in the harbour over the past 15 years, and has led to die-offs of adult and juvenile skates and low egg hatching success. The animals are unable to reproduce in the conditions in the Harbour.

“Macquarie Harbour is part of the Tasmanian Wilderness World Heritage Area and the Maugean skate is one of the World Heritage Area’s values.

”The federal government can’t just keep passing the buck to the Tasmanian Government. The federal Minister has obligations to act to protect the skate under the EPBC Act, the World Heritage Convention, Australian World Heritage management principles and the Tasmanian Wilderness World Heritage Area Management Plan.”