Tasmania Closes Southeastern Rock Lobster and Dive Fisheries for Three Months Over Antibiotic Risk from Salmon Farming

The Australian state of Tasmania has implemented a three-month closure of the commercial rock lobster fishery in the state's southeast, as well as dive fisheries targeting other marine invertebrates such as sea urchins, citing the use of antibiotics in nearby salmon farming operations. The closure runs from 15 November 2026 to 14 February 2027 and aims to "mitigate" trade risks associated with the use of an antibiotic called oxytetracycline (OTC). Salmon farming companies sometimes administer this antibiotic to fish to prevent mass mortality events typically caused by bacterial outbreaks during the warmer summer months.

According to the Australian Broadcasting Corporation (ABC), the closure is linked to the use of oxytetracycline at salmon farms operated by aquaculture company Tassal. As 2026 draws to a close, El Niño conditions continue to strengthen, increasing the likelihood of such events at Tasmanian salmon farms. The Australian Marine Conservation Society said the Bureau of Meteorology forecasts that by January 2027, strong, severe or even extreme marine heatwave conditions will occur across most waters around Tasmania, making farmed salmon more susceptible to disease and making salmon farming companies more likely to seek interventional treatments such as antibiotics to prevent high-mortality events.

In strictly regulated markets such as the EU and China, detection of oxytetracycline in wild seafood shipments could trigger export bans; however, these markets generally permit certain levels of oxytetracycline in farmed products. The antibiotic used in salmon farming has been detected in wild seafood batches as far as 14 kilometers from application sites.

Environment Tasmania marine campaigner Rebecca Howarth called such closures "grossly unfair," saying in a statement that wild-catch fishers are losing lucrative export opportunities because of a problem they did not cause. "Local wild fisheries are once again pushed to the back of the queue while the consequences of antibiotic use by large salmon farming companies are passed on to others," she said. "These closures will also disrupt commercial divers' efforts to remove invasive long-spined sea urchins, which are destroying reefs and kelp forests. Just when we need to keep pushing forward on work to control this destructive species, this is a setback. We should be preventing these risks at the source, rather than making local fishing businesses and marine conservation efforts pay the price."

According to ABC, a Tassal spokesperson said the company is "working with the wild fisheries sector to provide appropriate support" and noted that the closed area accounts for only 1.6% of Tasmania's historical annual rock lobster catch.