Overview
Atlantic salmon (Salmo salar) are distributed across the basin of the North Atlantic Ocean from the Arctic Circle to Portugal in the eastern Atlantic, from Iceland and southern Greenland, and from the Ungava region of northern Quebec south to the Connecticut River. They are anadromous fish because part of their life cycle occurs in saltwater and part in freshwater. Atlantic salmon were eliminated from most of their native range in the northeastern United States and Canada, but restocking efforts have re-established them in many watersheds.
U.S. Production
In the United States, Maine and Washington are the two largest producing states, with an estimated 40 million pounds of live-weight production. The average price for filleted products rose to $2.28 per pound in 2003. In 2004, the forecast is for a relatively strong market, with imports slated to only slightly expand. 2004 shipments are expected to be near 425 million pounds, valued at $950 million. Demand is expected to be tempered by factors that include a weaker dollar and adverse publicity on contaminant problems associated with outside pen-reared fish. (Source: Aquaculture Outlook, 2004.)
Atlantic salmon are cultured extensively at state, federal and private facilities throughout the northeast for restoration efforts, recreational fishing opportunities and as a food fish. Under culture conditions, Atlantic salmon eggs should be incubated at 42°F. Upon hatching, the temperature should be dropped to 38°F until the sac fry begins to accept prepared food. At this point, the temperature should be raised to 50°F, then slowly increased to a final maintenance temperature of 60°F. The pH should be greater than 6, and dissolved oxygen levels should remain above 7 ppm.
In the American Northwest, there has long been controversy about whether salmon aquaculture has beneficial or detrimental implications for the wild-fish resource. Whether there is common ground between sustaining wild salmon with hatchery-produced fish and the hatchery-based aquaculture of salmon was recently called into question by research reported in a fall 2006 edition of the Conservation Biology journal.
A group led by an Oregon State University geneticist cautioned that relying on hatcheries to sustain salmon runs is likely to fail in the long run without restoring river habitats. They found that fish raised from wild eggs in hatcheries will soon evolve traits ill-suited to the wild and that hatchery programs "essentially created a fish version of white lab mice." This finding suggests that they are very well adapted to handling, artificial diets and so on but that they do not survive well in the wild.
This has been a controversial issue. Hatchery fish make up about two-thirds of the wild-strain salmon and steelhead (trout) returning each year to the Columbia Basin, the largest producer of salmon on the West Coast. The returns represent just 5 percent of historical levels before dams, logging and other habitat degradation reduced populations and spawning-bed resources. Conservation groups, Indian tribes, fishermen, state and federal agencies, the timber industry, agricultural groups and property rights groups have been battling over the role of hatcheries and the role of artificial population enhancement for decades.
The bottom line: research confirms that steelhead raised for generations in hatcheries do poorly when they try to reproduce in the wild, but the first generation of fish raised from wild parents in hatcheries are as successful at reproducing in their native rivers as their wild cousins. This finding means that hatcheries can use wild-recovered stock for their breeding programs, supplementing their efforts to sustain or enhance the wild-fish resource, and that “aquaculture-strain” salmon are just that, a domestic animal well suited to confinement rearing. These results parallel other studies showing that even hatchery fish bred from wild eggs are inferior to wild-produced fish. This implies that there are three distinct courses for salmon resource protection: habitat restoration for wild fish, augmentation of the wild resource with “first-generation hatchery fish and use of “confinement-acclimated” strains for dedicated aquaculture production systems.
Imports
In 2003 U.S. Atlantic salmon imports totaled 414 million pounds, valued at $916 million. This was a 0.3-percent increase in quantity and a 12-percent increase in value over 2002. The lower increase in quantity resulted in a 23 cents per pound increase in the average price to $2.21 per pound. During the previous two years, the price had fallen about 23 percent. Most farmed salmon is imported from Canada and Chile. In 2003 these imports totaled over 400 million pounds. More of the imported fish tends to be fresh or frozen fillets, rather than whole frozen fish. In 2003 fillets accounted for two-thirds of total imports.
Sources
Aquaculture Outlook, ERS, USDA, 2004.
Census of Aquaculture (2005), USDA, 2006.
Salmon Fisheries in Alaska, Alaska Department of Fish and Game.
Study: Modern Hatcheries Aid Wild Salmon, Conservation Biology, 2006 - A group led by an Oregon State University geneticist cautions that relying on hatcheries to sustain salmon runs is likely to fail in the long run without restoration of river habitats.
Links checked February 2008.