For several years concerns have been raised about Tasmania’s salmon farming industry and the impact it is having on the state’s coastal wildlife. With the Tasmanian government’s long-term Salmon Industry Plan due to be released in May, several leading scientists and professionals have spoken out about the viability of the industry’s plans for expansion.
Members of the Tasmanian Independent Science Council are dedicated to science-based policy reform that will safeguard the Tasmanian environment’s long-term health. The group has called for a pause on further growth of the salmon industry until more robust scientific and regulatory frameworks are established. TISC has produced a Plan B with recommendations designed to transition the industry out of shallow coastal waterways and onto land and/or further offshore.
TISC’s leading water quality expert Christine Coughanowr said Tasmania boasts some of the largest salmon cages in the world but the untreated pollution from a typical farm’s 20 cages is contributing to the algal blooms and oxygen crashes that will also be exacerbated by climate change.
“Inland waters are also affected. Across the state, ten flow-through hatcheries release poorly treated wastewater into rivers and lakes adding to drinking water problems in some areas. Failure to prevent the water pollution that’s been attributed to untreated nutrient and faecal pollution released from salmon pens, and the risk to the survival of native species like the endangered Maugean skate, is unacceptable,” she said.
TISC member Lisa Gershwin, a marine biologist and ecologist, said another example of the science missing from the industry’s regulations involved south-eastern Australia’s endemic Burrunan dolphin, (Tursiops australis), a species that is found nowhere else in the world.
First named and classified in 2011 this bottle-nose dolphin is listed as Critically Endangered under the Victorian Flora and Fauna Guarantee yet has little protection in Tasmania.
“The Tasmanian dolphin likely to be most affected is now listed as Critically Endangered in Victoria but astonishingly it’s still not officially listed as Tasmanian fauna, and the species receives no special protection here,” Gershwin explained.
She said noise was a major factor for both dolphins and seals, but salmon farming had transformed previously quiet bays into permanently noisy industrial sites. It is an environment that creates serious health issues for marine mammals where echolocation is a crucial aspect of their lives, from finding food to social cohesion.
“In addition to the deafening thrum, the salmon industry sets off up to about 40,000 underwater ‘cracker bombs’ a year to deter seals. These explosives shatter bones, rupture eardrums, and herniate brain tissue, so imagine what they do to the echolocation of dolphins,” said Gershwin.
TISC Chair, Jamie Kirkpatrick, a conservation biologist at the University of Tasmania, said the salmon industry had ‘raced ahead of the science’ and for the industry’s long-term viability the increasing pressures of climate change, pollution and pests needed to be properly considered and addressed.
“Plan B recommends an immediate pause in expansion to let the science and regulation catch up so a major rethink of the fundamental principles of how and where salmon is farmed can be undertaken,” he said.
When it was first announced in 2021 former Primary Industries Minister Guy Barnett said the new plan would be guided by four guiding principles: no net increase in leased farming areas in Tasmanian waters; future growth to lie in land-based and offshore salmon farming; world-best practice through continuous improvement; and strict independent regulation.
Anne Layton-Bennett
‘Plan B: An alternative vision for salmon aquaculture in Tasmania’ is available at site-bp79amrv.dotezcdn.com/uploads/397ef5f921854efca03a403e963c8672.pdf