Salmon farmers in Tasmania are making efforts to increase oxygen levels in Macquarie Harbour, which has been depleted of oxygen. However, there has been no mention of calls for them to reduce the number of fish in order to protect the Maugean Skate, an endangered species that is on the brink of extinction. Scientists have warned that the skate could be wiped out by a single extreme weather event. Recent conservation advice from the federal government identified salmon farming as the primary human activity causing poor water quality, which threatens the Maugean Skate.
The federal government’s advice emphasized the need for urgent action before summer to address the low oxygen levels. It suggested that destocking fish pens would be the fastest way to achieve this, with mechanical solutions also being an option. On September 29, Salmon Tasmania announced that fish producers would be exploring potential engineering solutions, but there was no mention of destocking. The proposed trial will involve using a barge and pumps to extract seawater, infuse it with oxygen bubbles, and release it into deeper sections of the harbor. The two-year project, costing $6 million, will be partially funded by the Fisheries Research and Development Corporation, co-funded by the federal government. The trial is scheduled to begin in the summer, and the University of Tasmania’s Institute for Marine and Antarctic Studies will determine its feasibility.
Luke Martin, CEO of Salmon Tasmania, expressed confidence in the effectiveness of the technology, stating that it has been proven successful worldwide. He emphasized that the aim of the project is to offset the oxygen depletion caused by aquaculture activities and minimize the industry’s impact on the environment. Martin defended the project as a sensible and science-based response to managing risks to the skate, in contrast to what he referred to as “alarmist calls to remove aquaculture from the harbor.” The Bob Brown Foundation criticized the announcement, comparing it to BP claiming to lead the cleanup of the Deepwater Horizon incident. The foundation’s marine campaigner, Alistair Allan, argued that if fish farms had never been present in the harbor, the Maugean Skate wouldn’t be on the edge of extinction.
Federal Environment Minister Tanya Plibersek welcomed the trial as a positive step from the salmon farming industry but stressed the need for immediate action to protect the skate. She announced $2.15 million to establish a captive breeding program for the Maugean Skate, ensuring the creation of an insurance population while efforts are made to restore the health of Macquarie Harbour.