Writing in the Proceedings of the National Academy of Sciences, Stanford University professor Rosamond Naylor said booming demand for fish oil and fishmeal, driven by the popularity of Omega-3, is depleting of fish stocks.
Naylor said fish oil consumption is particularly important with regards to sustainability, and called for tighter regulation to reduce its use in aquaculture feeding.
The professor of environmental Earth system science said a 4 per cent reduction in fish oil would cut the amount of wild fish needed to produce one pound of salmon from 5 pounds to 3.9 pounds. By contrast, a four per cent reduction in the use of fishmeal would have very little environmental impact.
Adam Ismail, the executive director of the Global Organization for EPA and DHA Omega-3s, attacked what he called the underlying assumption that fish oil consumption will increase to unsustainable levels if demand for fish from aquaculture grows.
Crude fish oil production
Ismail said that levels of crude fish oil production have actually not changed materially in over 20 years and that annual production is steady at around 800,000 to 1,000,000 tons.
The industry representative said that the wild fish referred to in the paper come largely from Peru and Chile, where they strictly follow nearly all of the FAO guidelines for sustainable fisheries. As part of these guidelines, strict catch limits are imposed every year and these influence the amount of fish caught rather than demand for Omega-3.
He said: “This is why the amount of fish oil produced every year has not changed dramatically, even in the wake of rapid increases in demand from the aquaculture and omega-3 supplement markets.”
Because increased demand for fish oil does not affect supply, rising demand from fish farms will only lead to increased prices. Ismail said so long as aquaculture grows this market mechanism will force farmers to accelerate investment into alternative sources of omega-3s.