RAISING salmon in much the same way as industrial livestock and poultry farms is unsustainable, claims the Pure Salmon campaign, which claims that for every pound of farmed salmon, 3 pounds of fish in the wild are lost.
This should be food for thought for Filipinos who buy frozen salmon from Canada, New Zealand and the US, all of which are engaged in industrial salmon farming.
In 2005 Rosamond Naylor and Marshall Burke wrote in the Annual Review of Environment and Resources that breeding salmon in aquatic farms is akin to “raising tigers for their meat.”
Agricultural practices for animals can hardly be applied to carnivorous fish like salmon, they argued, and farming salmon is inherently unsustainable.
Fish farm operators simply have to catch huge amounts of fish to feed the penned salmon and a study in the journal Nature said 3 pounds of wild fish—anchovies, herring, sardines, menhaden, mackerel and the like—are needed to produce just 1 pound of marketable farmed salmon.
This means that the more salmon produced in fish farms, the higher the loss of marine species that would otherwise feed humanity.
“The voracious appetite of the global farmed salmon industry has impacted wild fisheries for more than a decade. On average, two-thirds of a farmed salmon’s diet consists of fishmeal and fish oil. These can only be obtained by catching and processing millions of tons of other fish. Salmon farms presently use about 573,000 metric tons [MT] of processed fish meal and 409,000 MT of fish oil annually,” said Albert G. J. Tacon in his “State of Information on Salmon Aquaculture Feed and the Environment,” which was prepared for the US World Wildlife Fund Salmon Aquaculture Dialogue.
Large quantities of fish feed are also reportedly wasted by salmon farms, which discharge between 15 percent and 20 percent of uneaten feed into the sea.
In Canada, specifically in the Bay of Fundy, salmon farms are said to discharge more than 10,000 MT of uneaten food annually.
Worldwide, said Pure Salmon, some estimates of lost feed run as high as 300,000 MT yearly. Moreover, schools of salmon themselves add to environmental pollution. In 1995 the world’s largest poultry and fish-feed manufacturer, Nutreco, confirmed a link between farmed salmon wastes that are high in nitrogen and phosphorus and the loss of oxygen in adjacent waters or eutrophication.
With such consequence, C. Talbot and R. Hole, who wrote “Fish diets and the control of eutrophication resulting from aquaculture” in the Journal of Applied Ichthyology in 1994, said control measures must be implemented.
Other studies have found that chemicals and pollutants contained in salmon feed are contaminating both the salmon themselves and the ocean floor beneath their pens.
- Hellou led a study in 2005 that found high concentrations of such pollutants under salmon aquaculture cages in the Bay of Fundy, New Brunswick, Canada.
The costs of fishmeal and fish oil, along with mounting environmental problems, are finally pushing some industrial salmon farms to reduce the use of wild caught fish for food and find cheaper alternatives.
They are now testing the viability of various types of vegetable proteins and animal byproducts, including chicken feathers and slaughter waste, as alternatives.
Norwegian scientists are toying with the use of genetically modified (GM) soy products for salmon feed even as others are contemplating on a wider use of GM-corn to replace fishmeal and fish oil for the diet of farmed salmon.
“Aquaculture cannot be economically or environmentally viable for carnivorous salmon. Such an inherently unsustainable method already causes an irreparable net loss of marine fish resources,” claimed Pure Salmon.
The group asked consumers to shy away from farmed salmon and patronize sustainable fish or seafood since each pound of farmed salmon means the loss of three pounds of wild fish from the oceans.
Marvyn N. Benaning