With salmon consumption at an all-time high in North America, now seems an opportune time to look more closely at this valuable resource. It’s difficult for most chefs to find the time to research such a complex topic, so here is a condensed look at the pros and cons of both aquaculture and wild salmon choices. The good news is that there are sustainable salmon choices available to us. Look at the Chefs Collaborative Seafood Solutions (released this fall) for some specific sources of these products.

Not all salmon tastes the same. In a blind taste test hosted by Chefs Collaborative (in May, 2000, at the French Culinary Institute in New York City) five types of salmon were prepared identically and compared. Tested for flavor, texture and aroma, here’s how they ranked:
* 1st - Wild Alaskan Coho, frozen at sea
* 2nd - Wild Oregon Chinook, fresh
* 3rd - Oregon Hatchery Chinook, fresh
* 4th - California Hatchery Chinook, fresh
* 5th - Maine Farm Raised Atlantic, fresh

We found statistics on the nutritional content (protein and fat-ratios) of farm versus wild salmon striking. FDA tests show wild salmon to have 20% higher protein content and 20% lower fat content than aquaculture salmon. Obviously we have all heard about the beneficial fat content of salmon, but a product which contains 30-35% fat by weight is considered by most to be excessive.

Wild salmon in North America consist of six species: Atlantic, King (Chinook), Silver (Coho), Sockeye, Pinks and Chums. Atlantic salmon are severely threatened, existing in small numbers in the wild in Maine and The Maritime Provinces of Canada. There is no wild Atlantic salmon sold commercially. Wild salmon range from the Sacramento River drainage north throughout Oregon, Washington, British Columbia and Alaska. While viable numbers still exist in their southern ranges, the healthiest populations and habitats exist in Alaska. In fact, due to the successful efforts of conserving and protecting wild salmon habitats, the Alaska Salmon Fishery recently received the Marine Stewardship Council’s label for sustainability. Fresh-caught, wild salmon is available nearly eight months of the year, with high quality "frozen at sea" (FAS) line-caught fish available during the interim.

The primary methods of salmon capture are: trolling a series of baited lines "trolled" behind a small boat; gill netting fixed nets which are positioned at the mouth of a river to ensnare returning runs of salmon; and seining a large purse shaped net which is reduced in size to trap the run of fish. Trolling or line-caught salmon exhibit the best overall handling, translating into the highest quality final product.

Wild populations come under pressure from numerous causes. Their habitat is altered by logging, road building, overgrazing of livestock, agricultural runoff, dams, and urban and industrial development. These populations also face competition for food, spawning grounds and migratory routes from both salmon hatchery fish and aquaculture salmon operations. Another major threat to wild fish is from sport and commercial fisheries and their management.

Aquaculture can be a potential solution to alleviating stress on wild salmon populations, but it is not without complications. Atlantic salmon (the most widely reared aquaculture salmon species) is reared in floating open net pens in bays and inlets. Salmon farms exist in British Columbia, The Maritime Provinces, Maine, Scotland, Ireland, Norway, Chile, Japan and other countries where cold, clear seawater can be found. The fish are fed a diet of fishmeal pellets and raised to a marketable size over a 2-3 year period. In the past 15 years, salmon farming has increased to a level where 50% of the world’s salmon is now sourced from aquaculture open net pens (hatchery fish is about 30% and wild fish the remaining 20%). This flood of fish-farm salmon has caused the price of wild salmon to drop from $5/lb in the late 1970’s to just over $1/lb today to the fisherman. This price decrease has forced many small-fishing boats off the water.

Salmon farms are input intensive. First, it has become necessary to source the eggs from hatcheries outside of their regions. In North America most of the fertile eggs for aquaculture originate in Scandinavia or Scotland. Second, the fishmeal for their food is composed of small pelagic fish (anchovies, capelin, etc.) harvested in the nutrient rich currents off Peru and South America. Typically, four pounds of fish meal is needed to create one pound of farm raised fish-creating "net loss" of protein in the food system. Removal of immense amounts of prey fish from any eco-system can have significant ramifications; transfer of large amounts of biomass from one eco-system to another can invariably produce imbalance in both systems. Third, rearing fish in such high densities present problems. Infectious disease outbreaks pose financial threats to operators so vaccines and antibiotics are often used to prevent potential epidemics. Sulfa drugs and tetracycline are often added to food pellet mixes as well as astaxanthin (an orange dye) to impart a rich red-orange color to an otherwise grayish flesh color. These additives and inputs invariably find their way into our food stream by settling to the sea bottom under the open net pens. Finally, the excrement of these aquaculture fish accumulates below their pens. A good-sized salmon farm produces the equivalent amount of sewage of a city of 10,000 people.

Reported environmental impacts from salmon aquaculture farms are diverse. Marine wildlife mortality consists of seabirds ensnared in protective netting and sea lions shot for preying on penned fish. Penned salmon prey on migrating smolts (immature wild salmon) journeying to the sea. They also compete for food sources of krill and herring, which nourish wild fish before their final journey home to their spawning grounds. Documented escapes of farm fish (360,000 Atlantic’s in one escape in 1997 from a Puget Sound farm) create problems in the wild. Escaped fish compete for habitat, spawning grounds and food sources. Dilution of the wild salmon gene pool can occur through interbreeding of farm and wild stocks.

Salmon farms can also threaten wild populations through concentrating and spreading infectious disease. ISA - Infectious Salmon Anemia, as well as other diseases, have been spread to wild stocks through their proximity to fish farms and escaped Atlantic populations. Entire river systems in Norway, Nova Scotia and Scotland have been dosed with the toxic chemical Rotenone to control such outbreaks.

There are alternatives to open net pens. Prototype closed systems - a floating closed-bottom pen with an attached water treatment system - have been developed and tested. While more expensive to construct initially, these systems clearly cover the true cost of rearing salmon in an aquaculture format. In Oregon, at Young’s Bay and other sites on the lower Columbia River, another alternative to conventional net pen aquaculture has been developed. On a small river that lacks wild salmon, young fish (raised in a hatchery in another location) are acclimated to saltwater in net pens and released at the appropriate age to travel to the Pacific and grow to maturity in the wild. Three to four years later, they return to Young’s Bay as mature adult Chinook salmon for selective harvest and sale. This "salmon ranching" approach avoids most of the environmental drawbacks of salmon farming, supports commercial fishing jobs and produces high-quality fish that can be caught without risk to endangered wild runs.

When buying salmon, we suggest that you ask for line-caught Alaskan fish first, as the most sustainable option with closed-pen farm-raised salmon a viable second choice. Copper River fish is just one of many top-quality runs of wild salmon available. Work with your fish suppliers to access the best fish. Consider using F.A.S. (frozen at sea) line caught fish; it is an excellent alternative to farm-raised fish. Support the Audubon’s Living Oceans Campaign and visit the Monterey Bay Aquarium’s website. Stay Informed!