Industrial Salmon

The Tasmanian salmon industry produces 50,000 tonnes per annum. According to the Tasmanian Government’s Salmon Growth Plan (Big Salmon Plan), There are 14 marine farm plans around the state. The table below summarizes the industry’s active and inactive finfish farming zones as well as areas under exploration licenses[1].

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Learning from Macquarie Harbour
Over 1,350,000 Salmon died in Macquarie Harbour due to Government’s broken regulatory and compliance system. The stocking limit in Macquarie Harbour peaked at 26,500 tonnes in 2016. The stocking density should never have been allowed to grow so high. It is now back to the 2015 level of 9,500 tonnes.[2] This stocking density reflects the biomass that can survive in the harbour (rather than any concern for rehabilitation) and that areas under the pens resemble an underwater industrial wasteland, devoid of aquatic life.[3] This kind of management of a public waterway represents world’s worst practise and Tasmanians are rightly concerned that the industry and government are incompetent, lack transparency, and cannot be trusted to ensure that other pristine waterways around Tasmania will not be destroyed in the same way.

Proposed Expansion 2018 - Storm Bay
Tasmania’s Salmon Producers are preparing for an expansion into Storm Bay that will double the size of the industry. The initial expansion is for 30,000-40,000 tonnes per annum with an aspirational target of 80,000 tpa. This represents a 160% increase in Tasmania’s total production, all a few kilometres from Hobart. This rapid upscaling suggests neither the government nor industry has learnt from its mistakes in Macquarie Harbour.

The government’s controls on pollution are among the worst in the world. The industry regularly breaks its lease conditions, but the government and regulator do nothing aside from lowering the thresholds which define non-compliance.

The industry expansion will create a concentrated nutrient input (dissolved and solid nitrogen pollution) in Storm Bay. Elevated nitrogen levels cause algal blooms and can re-suspend heavy metals trapped in bottom sediments. The Derwent has some of the highest sedimentary heavy metal concentrations in the world.[4]

All oceanic water passes through Storm Bay into the Derwent Estuary, Frederick Henry and Norfolk Bay. These bays are prime recreational fishing and boating areas and host most of Greater Hobart and the Southern beaches. The D’Entrecasteaux is already experiencing elevated nitrogen levels due to the presence of large nutrient input from fish farms. The urine and faecal pollution from the salmon will be around 2,296 tpa (initial expansion),then 4,592 tpa mainly in the form of dissolved nitrogen (approximately 85% of the total output is released as a solution into the water column).[5] (Derwent Estuary Program, (DEP) 2018)

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Storm Bay is considered by the Derwent Estuary Program to be part of a much bigger system that includes the Derwent Estuary, the current total human output of dissolved nitrogen into the estuary is only 327 tpa. Salmon industry modelling clearly shows that a portion of the pollution will be pushed into the Derwent Estuary, Frederick Henry and Norfolk Bay, though what percentage remains unclear.[6] Even 5% would represent a doubling of the current nutrient inputs. Any increase above current inputs will result in an increased risk of toxic algal blooms and heavy metal re-suspension.

[1]Department of Primary Industries Parks Wildlife and Environment, salmonplan.pdf, p 12, 2017
[2] ABC News, Macquarie Harbour Salmon, 2018
[3] ABC News, Macquarie Harbour Oxygen, 2017
[4] Derwent Estuary Program, Storm Bay Submission, 2018
[5] Ibid
[6] Ibid

 

Halt the March of the Sea Urchin

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Marine ecosystems on Tasmania’s east coast are under threat from the Centrostephanus sea urchin. Over-fishing of its key predator, the large Rock Lobster, and increasingly warmer waters caused by climate change have allowed this species to proliferate and spread further south.

If left uncontrolled Centrostephanus will remove all of the kelp from a rocky reef. It does not come back and the impact may be permanent. This destroys the habitat of juvenile Rock Lobsters and Abalone and virtually all other native species.

We are at risk of losing 32% of Tasmania's coastal reefs in the next four years unless we can stop the march of centrostephanus.

This would be a massive blow to Tasmania's Marine Biodiversity and economy. The Rock Lobster, Abalone and fishing industries all depend on this habitat for the continued survival of their businesses.

Rock lobster crisis

Destroying rocky reef habitats is causing a crisis for the rock lobster fishery as well as being an environmental disaster. The Rock Lobster fishery is the most valuable of Tasmania’s wild fisheries and it is a species highly prized by many Tasmanian recreational fishers. But across most of Tasmania’s east coast it has become virtually impossible to catch. Biomass levels are now down to less than 10% of their original numbers, meaning that fishery and species is on the verge of collapse.

With your help we can stop the spread of the sea urchin and prevent further decline in rocky reef habitat. We can ensure Rock Lobster exist for future generations.