Anchovy, one of the species detected in aquaculture feed. (Photo: Stock File/FIS)
Warnings on use of wild fish in aquaculture feed
Wednesday, April 25, 2012, 03:40 (GMT + 9)
A team of researchers from the Department of Functional Biology of the University of Oviedo detected eight species of wild marine fish belonging to high trophic levels in the food chain in aquaculture feed.
According to Alba Ardura, a researcher at the University and lead author of the study published in Fisheries Research, the resources that have been found are: Peruvian anchovy (Engraulis ringens), sprat (Sprattus sprattus), Pacific cod (Gadus macrocephalus), whiting (Merlangius merlangus), common herring (Clupea harengus), Pacific sandeel (Ammodytes personatus), horse mackerel (Trachurus symmetricus) and blue mackerel (Scomber australasicus).
While aquaculture has the potential to reduce the fishing pressure on natural resources, consumers prefer farmed species that are carnivorous, such as salmon and cod. These fish require tonnes of high quality protein for a rapid and optimal development.
"If these proteins are obtained from capture fisheries, aquaculture will no longer be an alternative to overfishing and will start to contribute to it, eventually becoming a risk to natural marine ecosystems," explains the researcher.
Scientists at the University of Oviedo analyzed a DNA fragment of commercial feed for aquarium cichlids, aquaculture salmon and aquarium marine fish.
After removing the oil and fat from the food, the DNA sequences obtained were compared with public databases to identify the species found, the agency Sinc reported.
While the industrial waste from some of these species can be used to manufacture fishmeal for farmed fish, Ardura explains that "some of the species found in the feed are traded as fresh products without processing them, and there are suspicions that its presence in aquaculture feed comes directly from capture fisheries," such as the case of herring and of Pacific sand lance.
"If species from capture fisheries are used to feed farmed fish, then aquaculture does nothing to reduce overfishing," notes the researcher.
Therefore, she recommends "urgently" reviewing the composition of aquaculture feed to replace it by other proteins so as to reduce the exploitation of natural fish populations.
Ardura proposes to increase efforts so as to achieve high-quality protein from other sources such as vegetable protein and in this way, "minimize the impact of aquaculture on wild populations."
By Analia Murias