Study suggests eating salmon-feed fish, instead of farmed salmon
One of the great ironies of salmon farming lies in the fact that even though the salmon themselves aren't wild-caught, their feed is partially made up of smaller fish that are. According to new research, it would be ecologically better if we just ate those feed fish ourselves.
The study was conducted by scientists from the University of Cambridge, utilizing data from the production of farmed salmon in Scotland for the year 2014. In a nutshell, the researchers wanted to compare the volume of wild-caught feed fish to the volume of farmed salmon that was harvested.
It was found that in 2014, 460,000 tonnes (507,063 tons) of wild-caught fish were used to produce 179,000 tonnes (197,313 tons) of salmon. Furthermore, 76 percent of the wild-caught fish were species that are commonly eaten by humans, such as anchovies and sardines.
Extrapolating those figures to a global scale, the scientists estimate that if people were to eat the wild-caught fish which are currently used in salmon feed, almost 4 million tons (3.6 million tonnes) of fish that are presently caught could be left in the sea each year. At the same time, a greater volume of fish would become available as a human food source.
That said, the researchers do admit that their figures are based on salmon production for one country, during one year. Further larger-scale research will need to be conducted, although it is believed that subsequent studies will paint a similar picture.
"Allowing salmonid production to expand further via its current approach will place exceptional stress on global fish stocks already at their limit," said the authors of a paper on the research. "Our results suggest that limiting the volume of wild-caught fish used to produce farmed salmon feed may relieve pressure on wild fish stocks while increasing supply of nutritious wild fish for human consumption."
The paper was recently published in the journal PLOS Sustainability and Transformation.
It should also be noted that various studies are looking into ways of replacing the wild-caught fish used in commercial aquaculture feed with more sustainable alternatives such as oil-rich algae.