A sustainable integrated aquaculture and aquaculture system might sound like the stuff of commercial farms, but it’s something you can do in your own backyard.
Dr Kate Hutson is the first to admit that she’s a bit crazy about her backyard chooks.
“In my Introduction to Aquaculture lectures I always put one slide in of my pet chickens,” she says. “Always, any lecture, whether it be live feeds in aquaculture or water quality, I relate it to my chickens.”
So when it came to finding a practical activity to look at solving sustainability challenges, she knew she wanted to do something with backyard birds – and ducks were the perfect fit.
JCU’s quaquaponics set up was hatched.
“What I wanted to do was create a new practical that incorporated integrated aquaculture because of its potential for sustainability,” she says. “So I went over and I saw Ben [at JCU’s Marine and Aquatic Research Facility] and I said, ‘Ben, I’ve got this crazy idea, you know the windmill you’ve got out there and those solar panels? Can we convert this into a multi-trophic integrated aquaculture system?’ And he just said, ‘When do we start?’.”
A multi-trophic integrated aquaculture system incorporates animals at different levels of the food chain and uses the by-products from one species as food or fertilizer for another. In this case, it’s redclaw crayfish, barcoo grunter, khaki Campbell ducks and a variety of herbs, fruit and vegetables.
“What we’ve chosen are endemic species, apart from the ducks,” Kate says. “It’s best to culture something that’s adaptable to the conditions that you can provide. Something that is found locally, that you can source locally, and is locally eaten are all favourable traits.”
So why the ducks?
“The ducks are sitting on the water, they defecate into the water and those nitrogenous wastes will help because plants use nitrates to grow,” Kate explains. “The principal is you’re recycling the waste and using the waste or by-products from one organism to then feed the next.”
Khaki Campbell ducks are also known for their prolific egg-laying, adding to productivity.
An integrated aquaculture system also has the potential to go off grid by harnessing solar energy to power any pumps which may be incorporated into the set-up.
“We’re using a pump to circulate the water through the system and that will improve the water quality, which then means you can increase your carrying capacity,” Kate says. “But you could have a more basic system that doesn’t involve electricity or pumps.”
Believe it or not, a simple quaquaponics system can be scaled down to fit on a suburban block.
“I could do it at home,” Kate says. “One of my aims is to really inspire the students and I want them to think about how to do this in their own backyard, maybe not replicate the entire system, but something smaller just to start and just to see that idea about sustainability because it’s so rewarding.”
JCU offers courses in Aquaculture Science and Technology at both Bachelor and Master’s level.
Cover image: Bethany Keats, JCU.