The name is from the Latin salmo, which originates from salire, “to leap.” Salmon is native to tributaries of both the North Atlantic and Pacific Oceans. While some species of salmon spend their entire lives in fresh water, most are anadromous; they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. Their homing instinct, called olfactory memory, is such that they are able to return to the exact spot where they were born to spawn. And the return, swimming upstream against the current, results in lots of leaping. Most species of salmon die within a few weeks after spawning.
Some species of salmon may grow as large as 110 pounds in weight and five feet in length and live as long as 8 years. The population, especially in the Atlantic and in the Snake and Columbia River systems in the Northwestern United States, has declined markedly in recent decades. North Atlantic wild salmon used to be half of the world’s wild salmon supply, now it’s 15%. Salmon from the Columbia and Snake Rivers is now less than 3% of what it was when Lewis and Clark reached the Pacific in 1805. This is partially due to the construction of the Chief Joseph Dam in 1955, which totally blocked salmon migration, and partially due to a long history of overfishing by competing fisheries in the states of Oregon and Washington. The Monterey Bay Aquarium’s Seafood Watch now lists only Alaskan salmon as a low sustainability risk.
By 2001, 60% of salmon consumed world wide was farmed. Today, it’s estimated that the number is closer to 80%. And not just in America; Europe, Japan and Russia all have increased salmon farming. While salmon is considered healthy due to high protein, high omega 3 acids and high vitamin D, farmed species, which often live in less than sanitary conditions, may contain high levels of dioxins and other contaminants. They are fed dye pellets to approximate the red color they would have in nature, and commercial feed that sometimes contains genetically modified ingredients. They are treated with antibiotics to prevent disease that results from life in a tank or pond under crowded conditions where the habitat can be polluted by their own waste or by pesticide run off from nearby farmlands, and viruses can find rich breeding grounds. If you’ve bought farmed salmon, some recommend that you remove the skin before cooking it to reduce exposure to contaminants.
Salmon should be displayed on ice at your fish market. Since smell is a good indicator of freshness, and you can’t detect smell through plastic, don’t by prepackaged fish; when your fish monger hands you your fish, sniff it through the paper wrapping. When you get it home, put it in the fridge immediately. Put ice in the bottom of a baking dish, lay fish on top of it, cover with plastic and put it on the lowest (coldest) shelf in the fridge. It will keep there for a day or two. If you must wait longer than that, freeze it for 2 to 3 weeks. While salmon can withstand grilling, I prefer to saute it in a non-stick skillet, assuring that the beautiful browned crust stays on the salmon, not on the grill grate.