Fish Farm Science is Clear - Environment Tasmania

Fish Farm Science is Clear

Tassal boss Mark Ryan has responded to the Four Corners probe into his company's practices by denying facts from key research groups including the Cawthron Institute, Melbourne University and IMAS. Published today, this editorial provides a timeline of the increasing ecological pressures in Macquarie Harbour, which is adjacent to a stunning World Heritage Area on Tasmania's West Coast.


Talking Point: Fish farm science is clear that big rise in production is dangerous

CHIEF executive Mark Ryan portrays the Four Corners probe into Tassal’s conduct as nothing more than a bun fight between competitors (Talking Point, Mercury, November 5).

Mr Ryan seemed to deny the validity of government-funded research on Macquarie Harbour by the University of Melbourne, dismissing it as “competitor’s scientific research”. His denial of the results of scientific research goes further, with his claim that “some people have their own views on Macquarie Harbour”.

If we are to believe Mr Ryan, what we are seeing in Macquarie Harbour is not repeated warnings by independent scientists of an ecosystem under stress, but opinion, a mere difference of views between competitors.

It is crucial the record is corrected, not just for the reputation of the scientists involved, but to address questions as to the accuracy of reports Mr Ryan is providing to government and shareholders.

The research Four Corners quoted on the lethal conditions in Macquarie Harbour last summer was not Huon Aquaculture research, it was funded by the Fisheries Research Development Corporation. Huon Aquaculture gave University of Melbourne scientists access to their lease site to do the research. If Mr Ryan gave independent scientists access to Tassal lease sites to monitor fish stress levels in Macquarie Harbour last summer, we encourage him to release the results of this research. We also encourage Mr Ryan to move beyond rhetoric and provide details of what comments made by Four Corners were misleading.

Unfortunately, some of Mr Ryan’s comments are misleading. He states: “Heat stress and low dissolved oxygen was an issue last summer because of the abnormal weather conditions. That is a fact.” Publicly available government data shows dangerously low dissolved oxygen levels in Macquarie Harbour have persisted since 2013. These conditions are not limited to a one-off extreme weather event. Plummeting oxygen levels began with the 360 per cent increase in salmon production and have not recovered.

What follows is a timeline of the ecological crisis in Macquarie Harbour, based on government data and scientific facts provided by New Zealand’s Cawthron Institute, the University of Melbourne and the Institute of Marine and Antarctic Studies:

2013: Industry data shows a 360 per cent increase in production is accompanied by plummeting dissolved oxygen levels, median levels dropping from 20—40 per cent in 2010-11 to 5 per cent in 2013-14.

FEBRUARY 2014: The Tasmanian Salmonoid Growers Association establishes an inquiry into oxygen decline, the Macquarie Harbour Dissolved Oxygen Working Group.

MARCH 2015: Leaked documents from this group show licence conditions have been breached at all fish farms. Faecal matter has built up under pens. Two species of dorvilleids — a worm that feeds on faeces and is used as an indicator of serious pollution — are present at most lease sites. Bacteria mats have formed at two lease sites. A degraded environment has led to increased fish disease.

MARCH 2015: Industry sources leak an email from Huon Aquaculture and Petuna Seafoods chief executives to Premier Will Hodgman. It describes serious environmental and fish health warning signs, and urges the Premier not to approve Tassal’s request for an increase in production.

APRIL 2015: The Government commissions the Cawthron Institute to review conditions and assess whether the monitoring is effective in detecting salmon farm impact.

MAY 2015: 85,000 fish are suffocated in Macquarie Harbour. Petuna blames a one-off storm event.

AUGUST 2015: The Cawthron Institute report documents a “biological system under stress”, with serious impacts up to 7.5km from fish farms. It finds a correlation between increased fish farming and low oxygen levels and states that government regulations are insufficient to monitor impacts.

AUGUST 2015: A rare chronic disease called mycobacteriosis is found in farmed salmon in Macquarie Harbour. A Department of Primary Industries internal discussion paper, obtained by the ABC through Right to Information laws, reveals the disease is linked to degraded environmental conditions.

SEPTEMBER 2015: The Tasmanian Government responds to the Cawthron Institute Report. There are no penalties for companies. None of the recommended improvements to monitoring are adopted. The Government commissions further research.

APRIL 2016: Government responds to a continued evidence of an abundance of pollution indicator species by changing the law to remove this limit on pollution, pending further research.

APRIL 2016: Government approves an increase in salmon production in Macquarie Harbour, from 20,000 to 21,500 tonnes a year.

OCTOBER 2016: New FRDC research shows conditions in the summer of 2015 breach the maximum temperature and minimum oxygen supply salmon can withstand before they stop eating and develop skin lesions.

OCTOBER 2016: Research requested by the Government to determine whether pollution indicator species (dorvilleids) are an accurate indicator of salmon farm pollution finds they are. Minister Rockliff does not reintroduce licence conditions relating to dorvilleids.

Laura Kelly is strategic director of Environment Tasmania.

Published in The Mercury here