Peter Whish-Wilson (Tasmania, Australian Greens) Share this | Link to this | Hansard source

I seek leave to table a report.

Leave granted.

I table this report with the best interests not just of the Tasmanian environment at heart but also of the salmon industry. I rise tonight to talk about a growing risk for the environment for the fish farm industry on Tasmania's west coast. The Greens were anonymously given a copy of a draft confidential report from the Macquarie Harbour dissolved oxygen working group dated 24 August 2014. This group is made up of representatives from the fish farm industry, CSIRO, IMAS, water consultants and the state government primary industries department and was formed to determine the extent of the dissolved oxygen problem and what was causing it.

A good level of dissolved oxygen is essential for aquatic life. It is a key barometer of water quality. According to the report, from 2009 to August 2014 there was a clear downward trend in the dissolved oxygen levels of the harbour's deep waters—that is, water deeper than 15 metres. As the report states:

Isolation of deep water in the harbour has resulted in a naturally low dissolved oxygen environment that may be vulnerable to further increases in oxygen demand. Dissolved oxygen levels have been declining since 2009 and further decreases may have a direct impact on both the ecology of the harbour and aquaculture production.

Specifically, dissolved oxygen levels less than 2 milligrams per litre are now very common below 20 metres and occasionally come to within 12 metres of the surface.

The report points to a number of factors that could be responsible for the plunge in oxygen levels, including changes in Hydro Tasmania's dam releases, low rainfall, high river flows and a significant expansion of fish farms over the same period. The report acknowledges that several indicators of marine health are not being measured in Macquarie Harbour, such as pelagic biological oxygen demand and labile carbon. In 2010-11 environment groups and the Greens were criticised for calling for better baseline scientific data and rigorous monitoring before fish farms were permitted to expand in Macquarie Harbor. And now we see that there is still not enough data for us to understand what it is going on.

This report recommends continuing current monitoring and adding those indicators not currently measured as the group decided that it needed further data before the decline in dissolved oxygen can be definitively attributed. It also recommends developing a detailed carbon, nitrogen and oxygen budget for the harbour; that hydrodynamic and biogeochemical modelling should use past conditions to examine future scenarios relating to changed river flows and salmon production; and exploring how fish farms could adapt management according to dissolved oxygen fluctuations and river discharge conditions.

Macquarie Harbour is on the doorstep to the World Heritage Area and is home to nationally threatened animals such as the maugean skate. If dissolved oxygen levels in the harbour are compromising fish farms, that threatens not only their viability but the survival of our native animals. If the Macquarie Harbour aquatic and benthic environment is compromised, this is likely to have adverse impacts on sustainable stock biomass, including bacterial issues impacting fish health and costs of production, such as an increased use of antibiotics. This report suggests an immediate response from the government on this issue. The fact that it was anonymously leaked to us probably suggests a lack of action since it was first published. But I would be happy to be proven wrong. Tasmanian Premier Mr Hodgman and Minister Rockliff should come clean on what is going on in Macquarie Harbour. What information do they have relating to this report's findings?

What does the Environmental Protection Agency know about changing oxygen levels in Macquarie Harbour?

If nationally listed threatened species are all at risk then, under the Environment Protection Biodiversity and Conservation Act, the state government needs to alert the Commonwealth minister. Has this happened? If not, why not?

In 2012 the Commonwealth determined that fish farm expansion was not a controlled action under the EPBC Act but, now that the water quality appears to be deteriorating, should this decision be reviewed?

I intend to write to the Commonwealth minister, urging him to investigate whether the state government is doing the right thing by industry and by threatened species in Macquarie Harbour. Fish farms have emerged as a significant player in Tasmania and they have certainly played off Tasmania's clean, green brand.

To me, it seems logical that stakeholders in the industry, especially the three big salmon producers, would be pushing the government to take action to resolve or prevent any dissolved oxygen problem and would willingly agree to change their practices to avert potential adverse environmental or economic impacts.

Is the Tasmanian government knowingly allowing companies to get away with farming practices that could impede effective action? The Greens believe the Tasmanian government should be taking a precautionary approach until it can better understand what is going on in the harbour. Fish farm stocking rates should be kept under any current limit and should not be increased until there is a definitive answer to the dissolved oxygen problem and what is causing it.

These leaked documents suggest Macquarie Harbour is potentially a ticking time bomb not just for the environment but potentially for the economic sustainability of the Tasmanian salmon industry and the many Tasmanians it employs—something that I know you, Mr President, understand.

If Tasmania's clean, green brand is to have integrity and longevity, the state and federal governments must work with stakeholders and act quickly to understand and rectify potential environmental problems. And they must do so with transparency.