THE Chilean Government’s emergency salmon committee, convened in late April. Amongst other things the committee is calling for a comprehensive study to determine exactly how much salmon production Chilean waters can handle.
Chilean salmon farms produce, on average, 25 kilos per cubic metre, according to the Santiago-based environmental NGO Fudación Terram. In Norway, the world’s leading farmed salmon producer, the concentration is significantly lower: 15 kilos per cubic metre, it says.
Benjamin Witte’s Patagonian Times article provides further details on the Committee’s challenges and some hard hitting opinion from Terram.
What stocking densities are achievable with other species? Any insights on Barramundi available Greg?
I spoke with Ian McRobert today about his Semi Intensive Floating Tank System (SIFTS) technology. The interview includes links to videos and pictures of his waste minimising aquaculture systems.
Ian and his team are using low pressure air in very unconventional ways to generate some significant advantages, especially in promoting a clean environment for fish growth and through innovative approaches to waste handling.
This is a picture of a small scale trial of the SIFTS system in Fremantle Harbour in Western Australia. The trial is a breakthrough in that it has gained the support of the Fisheries Department, the Environmental Protection Agency and the Port Authority.
Finfish: Ian, you have been able to achieve some some impressive stocking densities with your SIFTS approach. Can you share with us your present metrics?
McRobert: Yes Andrew, we have experienced exceptional carrying capacities with our system. Our experience is that fish can be cultured at stocking densities above eighty kilos per cubic metre without the need to resort to pure oxygen or sophisticated recirculating aquaculture system (RAS) equipment.
Finfish: How do you achieve this Ian?
McRobert: Our SIFTS waste extraction system efficiently removes almost all of the solid waste - in fact up to 95% of all faecal matter is extracted quickly. Our objective is to minimise the opportunity for material to suspend or dissolve in the water column.
Finfish: Ian, you have secured environmental approval and the endorsement of the Fremantle Port Authority to trial SIFTS?
McRobert: With its waste extraction capabilities, SIFTS is able to avoid some of the biggest challenges facing aquaculture like the environmental effects caused by some cage operations conducted in nearshore areas.
Finfish: What other techniques do you use to maintain a clean growing environment for your fish, Ian?
McRobert: we use a patented liner technology that allows us to easily and thoroughly clean the tank to promote as pristine a growing environment for our fish as possible. The liner also gives us major benefits in stress free fish handling techniques. You can check this out easily by reviewing the videos on our Website.
I have included a link to the fish handling videos here.
Finfish: Thank you Ian.
McRobert: Thank you Andrew. Here are a few pictures of our system in Fremantle Harbour to allow Finfish readers to see what we are up to.
If you would like to find out more about the SIFTS approach, please visit the McRobert Aquaculture website.
