Conservation groups say the loss of four dugongs in the Wide Bay Burnett Region over the last two weeks is tragic and highly suspicious, with some of the deaths possibly linked to gill nets.
The World Wide Fund for Nature-Australia and Australian Marine Conservation Society (AMCS) are calling for an investigation.
One of the threatened mammals, which washed up on Rainbow Beach, had a heavy chain wrapped tightly around its tail.
"Either this animal became entangled in a buoy chain or someone has tried to weigh it down to avoid detection," said WWF-Australia Sustainable Fisheries Project Manager Simon Miller.
Two other dugongs, along with a Queensland groper were found along the banks of the Mary River, while another dugong washed ashore at Archies Beach near Bargara.
"Boaties have reported heavy net fishing effort in the Mary River in recent weeks. It's highly suspicious that following that activity two dugongs and a groper suddenly wash up dead," Mr Miller said.
Dead dugong in Upper Mary River. Pic: WWF
The gill net fishery in Queensland will lose its export accreditation under the Commonwealth EPBC Act on 1 October in part because the Queensland government has failed to act on reducing the risk to threatened species.
"If commercial fishers did weigh this dugong down, their cruelty is a reminder of the consequences of poor fishing practices along the Queensland coast. It highlights why Federal Environment Minister Ley has intervened and will revoke the export licence of the ECIFFF (East Coast Inshore Fin Fish Fishery)," said AMCS Fisheries and Threatened Species Campaign Manager Tooni Mahto.
"Horrific practices like this should be stamped out with proper monitoring. We urgently need to see an independent observer program or cameras on boats, so the public know just how many dugongs and other threatened species are being caught in commercial gill nets," Ms Mahto said.
WWF-Australia and AMCS urge the Queensland Government to immediately pass the regulations required to implement the Sustainable Fisheries Strategy.
Dead dugong at Beaver Rock, Mary River. Pic: WWF
"These sad deaths emphasise why we need to see improved fisheries management in Queensland, with an urgent need for a Bycatch Management Strategy and individual fisher accountability to reduce the likelihood of future entanglements and ensure areas are closed to fishing when too many threatened species are caught," Mr Miller said.
The spate of dugong deaths highlights the need for a Net-Free North to create a safe haven for dugongs, he added.
"It is clear that gill net fishing and dugongs do not mix, the Queensland Government needs to do more to ensure the protection of our iconic marine wildlife.
"That is why WWF is calling for commercial gill net fishing to be banned between Cooktown and the Torres Strait, to protect the largest population of dugongs on the east coast as well as threatened sawfish, turtles and dolphins.
"WWF is urging the Queensland Government to prioritise the purchase of these licences as part of a $10m structural adjustment package for the commercial fishing industry," Mr Miller said.
WWF-Australia and AMCS are calling for a thorough investigation and for the Queensland Department of Agriculture and Fisheries to analyse Vessel Monitoring Systems to see which fishers have been operating in the area in recent weeks.
