One of the great ironies of salmon farming is that even though the salmon itself is not wild-caught, part of its diet is made up of the smaller fish that are. According to new research, it would be ecologically better to eat these forage fish ourselves.
The study was conducted by scientists from the University of Cambridge, using data from farmed salmon production in Scotland for the year 2014. In a nutshell, the researchers wanted to compare the volume of fish d wild-caught feed to farmed salmon volume. which was harvested.
It was found that in 2014, 460,000 tonnes (507,063 tonnes) of wild fish were used to produce 179,000 tonnes (197,313 tonnes) of salmon. Additionally, 76% of wild-caught fish were species commonly eaten by humans, such as anchovies and sardines.
Extrapolating these figures to a global scale, scientists estimate that if people were to eat the wild fish that are currently used in salmon feed, nearly 4 million tonnes (3.6 million tonnes) of fish that are currently caught could be left in the sea each year. At the same time, a larger volume of fish would become available as a human food source.
That said, the researchers admit that their numbers are based on a country’s salmon production for one year. Further research on a larger scale will need to be carried out, although it is believed that further studies will paint a similar picture.
“Allowing salmonid production to expand further via its current approach will place exceptional stress on already stretched global fish stocks,” the authors of a paper on the research said. “Our results suggest that limiting the volume of wild-caught fish used to produce feed for farmed salmon can relieve pressure on wild fish stocks while increasing the supply of nutritious wild fish for human consumption. “
The article was recently published in the journal PLOS Sustainability and transformation.
It should also be noted that various studies are investigating ways to replace wild fish used in commercial aquaculture feed with more sustainable alternatives such as oil-rich algae.
Source: PLOS via EurekAlert