Prawn farmer turning waste water into cash

Alistair Dick farms prawns near Ayr in north Queensland, where he’s developed an algae pond to treat waste water. He’s now producing a type of seaweed that’s in demand in Japan.

“In applying for a new prawn farm license under the EPCA (Environment Protection and Biodiversity Conservation Act) a new benchmark was set in environmental compliance,” Dick says.  “To meet that compliance we had to find a new set of ways to treat waste water on farm.”

Only when these requirements are met can fish farms release used water back into the natural environment. This was a tall order for Pacific Reef Fisheries, considering it turns over 3,000 megalites of waste water a year. Mr Dick’s solution was to use large algae ponds and sunlight to purify the water and in the process cultivate a type seaweed that’s popular in Japanese cooking.

As the seaweed grows in the sunlight it produces carbohydrates and protein by removing the nutrients from the waste water. This is where waste water is purified through a filter device or micro-strainer to remove unwanted bacteria. “But the benefit is we’re also able to produce a saleable product at the end so it’s a win-win for the farm,” Mr Dick says.

MDB Energy is the company responsible for processing the seaweed and getting it ready for the Japanese market.  Kyle Greg, lead biomass technician for MDB Energy, says the seaweed needs to be rinsed, dried and crushed into 2 to 3 millimeter pieces before it can be packaged and sent to Japan. “When it dries and gets ground down it’s flaky like basil or parsley,” he says. “Other countries such as China use it but I think Japan is the main market we’re going to focus on.”

“As far as aquaculture goes seaweed farming stems back thousands of years in China and Japan. “But certainly in general Australian produced food is seen as clean and obviously we can create good demand for Australian grown products. “So certainly in Japan it’s something that they’re very keen on.”

Source: ABC net