Fish farms in Macquarie Harbour are the greatest threat to survival of ancient ray-like species, scientists advising Australian government findScientists advising the Australian government on how to save the threatened Maugean skate from extinction have recommended the salmon industry be either scaled back dramatically or removed from Tasmania’s Macquarie Harbour after finding fish farms are the greatest threat to its survival.
The recommendation the industry should be cut back is likely to draw a sharp response from the Tasmanian Liberal and Labor parties, which both strongly back the $1.3bn industry. Macquarie Harbour produces only about 13% of Tasmanian salmon, but industry supporters argue it is an important hub and employer on the state’s remote west coast.
The threatened species committee report said the main threat facing the species was degraded water quality, primarily due to “substantially reduced” levels of dissolved oxygen across the harbour, a third of which was within a world heritage area.Previous studies have said the problem was caused by fish farms, hydro power stations altering upstream river flows, gillnet fishing and rising temperatures due to the climate crisis.
It echoes advice from the committee a year ago that called for urgent action including reducing the amount of salmon before last summer. Its latest report also recommended trying to mechanically improve dissolved oxygen levels, better management of the flow of the Gordon and King rivers into the harbour and a captive breeding program for the species.Our Australian morning briefing breaks down the key stories of the day, telling you what’s happening and why it matters.