Nile tilapia, Oreochromis niloticus. (Photo Credit: Bjorn Christian Torrissen CC BY-SA 3.0)
Tilapia may aid to get a more sustainable aquaculture
Tuesday, October 08, 2013, 04:50 (GMT + 9)
Nile tilapia (Oreochromis niloticus) could be the answer for a sustainable future for aquaculture. This is stated by a group of researchers working on an experimental project to change farmed fish feed for microalgae-based feed.
“We know that aquaculture is going to be increasingly important for achieving food security around the world. It’s the fastest growing food sector, but it’s growing in some ways that are unsustainable and raise real problems,” pointed out Professor of Sustainability Science at Dartmouth College, Anne Kapuscinski.
Kapuscinski, who is also Chair of the Environmental Studies Programme at Dartmouth’s College, and was distinguished by Sherman Fairchild Foundation pointed out that production of fish such as anchovies and menhaden, among other species which are destined for fish feed, has led to the overfishing of these species, as a direct consequence of aquaculture growth.
For this reason, the Professor’s team is aiming at producing marine micro-algae-based fish feed on a commercial level. The team is also trying to find acceptable substitutes for the fish feed rather than using fish which are desirable for humans to eat such as anchovies, herring and mackerel.
Apart from avoiding the use of wild fish, another desirable side-effect of the new fish feed is that a micro-algae diet could also mean cleaner water.
“The current aquaculture diet produces excessive phosphorous levels in aquaculture effluents,” says a researcher at Kapuscinski’s team. “Results of our first experiment suggest that incorporating micro-algae into the diet led to more efficient retention of the diet’s phosphorus, and this will also lead to cleaner aquaculture effluents and cleaner water,” the researcher adds.
In an earlier study published this year, Kapuscinski proved that aquaculture production needs more wildfish to function properly than it produces in the form of edible meat from farmed fish, resulting in “a net removal of fish on a global basis.”
The team of reasearchers in August started the second phase of a study to evaluate microalgae as an alternative source of feed for the tilapia. In the first stage, the group analysed how these fish digest three different types of microalgae and compared the results with the digestibility of other foods made with oil and fishmeal. The experiments have revealed that marine microalgae with high omega-3 fatty acids were the best, and even more digestible than commercial feed.
By Gabriela Raffaele