Aquaponics an answer to Pacific's food security
Updated October 12, 2011 11:07:35
The chronic water shortage in Tuvalu, Tokelau and the Samoas is raising concerns that some islands may face widespread crop failures. But marine and aquaculture researchers say there is a way to tackle the food and water crises. Aquaculture specialists in American Samoa say the use of aquaponics to grow fruit and vegetables could lead the way to future food security.
主持人: Geraldine Coutts
主講者: Ephraim Temple, the Sea Grant program coordinator at American Samoa's Community College
TEMPLE: Aquaponics is where you grow fish and plants in the same water, so as you feed the fish, they produce waste and the waste is used by the plants as fertiliser, so the water is recycled over and over to raise both fish and plant crops.
COUTTS: Even though it's efficient and economic when it comes to the use of water and the amount of water. Isn't this also too much water what given the crisis that's happening in a number of the nations at the moment?
TEMPLE: If you look at the literature for the amount of water that's required by traditional farming in soils, compared with the amount of water used for producing crops and aquaponics, you find that's about ten times less water usage in aquaponics. And so one could argue that it does use water conservatively and less than growing in traditional farming. So places that have little water, this is actually an ideal way to produce crops, because your recycling the water over and over. So may be initially to fill your tanks, then you do need as much water as your tank sizes are, but after that, then it requires very little to maintain the system.
COUTTS: And what about sort of bugs in the water and pollution, does that need to be filtered out so it doesn't devastate the crops that your trying to grow?
TEMPLE: In traditional aquaculture, where you have either ponds or tanks and you're raising higher quantities of fish. You have to deal with effluent that is full of nitrogen and that can be a problem. The beauty of aquaponics is the waste that's coming from the fish is actually taken up by the plants in that same system and so you have little to no run off to begin with, because the waters recycled and any run off that you do have has very low pollution in it as far as excess nutrients. So that's really the beauty of the system.
COUTTS: Well, your colleagues, the American Samoa Community College in partnership with the University of Hawaii will be hosting a workshop next week on building aquaponics capacity. How can you build the capacity, is it just having more tanks right throughout the region?
TEMPLE: Sure, that's one way. Another way is just giving people options. If they know that this is something available to them, that you can raise crops this way, then more people will be willing to go there. People often think that farming isn't for them, that their land is to full of sand or coral or to uneven, but aquaponics opens the door to growing, for people to have gardens in their backyards where those conditions are present. So I think if that is an option to them and they're understanding it, they will adopt that type of farming and start raising their own crops. That then improves their food security as well as conserves their water - producing this food that they're raising themselves.
COUTTS: Because no soil is required?
TEMPLE: That's right, that's right. So on many of these low lying atolls, the soil is poor to begin with, and most of the food is raised in the inner most part of the atoll, where they've kind of made a soil. But in this with aquaponics, people living right along the shore, they can build a small farm and they don't need soil at all.
COUTTS: Alright, to what extent could the food security be boosted using this method, aquaponics?
TEMPLE: That's a tricky question. I don't know if the economics of that have been analysed closely. But if every family were to establish their own aquaponic system, just on a small footprint of may be 30 square feet, you could produce all your plant food for your family. So that's really a small footprint and then you're relying solely on yourself to produce your food. Then you'd have to look elsewhere for your proteins, but at the same time, you know that you're raising fish in your systems as well. So as long as you're harvesting fish and plants, you're basic nutrition is covered. If you need specialty items, then that would have to come off island.