30 Oct 2013

Contributing to the development of a major aquaculture production zone in Western Australia

We supported the Department of Fisheries (DoF) in Western Australia in the development of a major aquaculture production zone in Cone Bay, North Western Australia.

We supported the Department of Fisheries (DoF) in Western Australia in the development of a major aquaculture production zone in Cone Bay, North Western Australia. We conducted an Environmental Impact Assessment (EIA), following which, we developed an Environmental Monitoring and Management Plan (EMMP) for the project.

DoF wanted to support the development of aquaculture by supplying a suitable site, where production conditions were well described and all environmental permissions and licenses were in place.

Increased concentrations of nitrogen in the worst case scenario – 20,000 tonnes/ year. All values are below impact threshold level.
We conducted extensive hydrodynamic and biological field work to establish the baseline conditions. We also built an ecological response model that could be used to assess the potential impact from major pressures (nutrients, organic debris) on the most important marine ecological components (in-fauna and corals in the Bay). We ran a number of different scenarios, varying production volume feed conversion rates, stocking densities and position of production cages.

The bay is well-suited to the needs of the prospective aquaculture project. It is dominated by tidal flushing with a tidal range of 9 – 14 m. Every 12 hours at the peak of the flood tide, an eddy is created that vacuum cleans the seabed and sucks out all the pollutants: organic debris, fish excretions and feed residuals from the production zone. The conclusion was that even with a maximum production of 20,000 tonnes/year, no impacts were expected.

The area is particularly well suited for Barramundi and the daily tidal exercises of the fish produce a meat texture and taste in the fish, which is highly sort after both on the domestic and in the international market.