As seductive as the idea of open net pen-farming of salmon is, particularly its enticingly cheap start up costs, several serious issues exist that will never be correctly addressed even with money, scientific advances and engineering.
Additionally, the buildup of marine debris on the nets and mooring appendages is never fully cleaned out, even in the best of circumstances. A new term has evolved – biofouling. It’s a bit more complicated to take care of than, let’s say cleaning out a stable. While biofouling needs to be removed almost weekly to prevent the buildup that contributed to the disaster in the Puget Sound by Cooke Seafood, it currently requires chemicals that are also deleterious to marine and ultimately human life. As with Teflon, these chemicals will ultimately have to be outlawed for use in the oceans for obvious reasons.
A final issue is two-pronged: the spreading of pathogens from farmed stocks to endangered fish populations and the interbreeding of escaped alien farmed fish with native wildfish populations. Farmed salmon suffer enormously from sea lice, which cling to them from infancy to harvesting. They get doused with a delicing solution and in addition are
Studies have found that hybrid offspring are less able to survive in the wild and that interbreeding constitutes genetic pollution that reduces the evolutionary fitness of the already declining wild population.
Almost any independently researched article that I have read almost screams out that open net pen fish farming should be banned. They produce, in my mind, an artificially low-priced salmon – based on either leased ocean acreage at very cheap prices or, in the case of Chile, the ocean acreage is free. Their companies are not held accountable for removing biofouling debris (the fines we have seen do not cover the recovery costs from the damage done to the maritime area) or pay any sort of tax on the amount of toxic waste their pens excrete onto the ocean floor. Clearly, another cleaner technology must be developed and funded to supply the planet with fish. And these open net pen fish farms need to be banned. So far, Argentina is the only country to do so.
And yes there is – it is called Recirculatory Aquaculture System or RAS. Its inventors, technicians, engineers and investors hope that this new and evolving technology will upend the current open pen farming system. Briefly, water is recycled and reused through a series of filtration processes both mechanical and biological which remove “suspended matter and metabolites.” RAS is designed for land-based, high density aquaculture, in which the fish swim in tanks in buildings against a strong but regulated current. Water temperature and quality, as well as pathogen control are tightly monitored. In most cases, fresh water for the younger salmon is used and then later sea water tanks are used until the salmon or trout are market ready. Still, two thorny issues remain: how best to return the filtered waste water back to its source and how to feed the fish without using wild small fish stocks, which are important for local economies.
Start-up costs are high, so that regions in which this technology is evolving have to provide financial incentives, and the companies themselves have to get private investment as well. While several of the RAS fisheries still have waste-water issues, the one currently developed in Wisconsin under the name of Superior Fresh may offer the optimum solution. The water used for raising market-ready fish is then used to hydroponically grow greens. The feed is now made from fish trimmings, oils and poultry trimmings. The authors of Salmon Wars describe it best.
One of the co-founders of Superior Fresh told the authors that for five pounds of sustainable fish feed, the company gets five pounds of marketable salmon and twenty-five pounds of “organic” greens. (hydroponic vegetables now get the US Organic certification, a term that is bitterly contested by organic farming organizations). And this farmed salmon tastes better than the open pen farmed version, according to a tasting panel in New York City and the authors themselves.
Some readers have asked for suggestions as to what to follow for their own seafood purchases. Having looked at several
As far as national grocery store chains go, Whole Foods seafood program is probably the best. It’s not perfect, as Greenpeace will tell you, but at least they are trying to be sustainable seafood team players. Our local seafood store MAS Seafood, is very up-front about where they buy and why, and there is always a nice selection of wild caught seafood as well. I am somewhat wary of seafood guides from organizations that have a corporation as their funding partner, such as Sysco or Unilever. Wherever you purchase, be the demanding consumer and ask questions. Sometimes, there is no other choice between wild and the open net- pen farmed fish, but your voice is needed at the fish counter.
After owning one of the best cooking stores in the US for 47 years, Nancy Pollard writes a blog about food in all its aspects – recipes, film, books, travel, superior sources and food related issues.
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