Some Basics on
in U.S. Rivers
Atlantic salmon (Salmo salar) is a highly prized food and game fish once found in nearly every major coastal river in New England. Salmon have a complex life history in that they live in both fresh and salt water and they migrate hundreds or thousands of miles. They spend their first one-to-three years inland, in streams and rivers. Eventually they migrate downstream to the ocean, where they may travel as far as the shores of Greenland. After one or two years on the high seas, the adult fish return to their natal streams to spawn.
At one time, salmon populations could be found in at least 34 Maine rivers and 11 major U.S. watersheds outside Maine. A combination of fishing and human-caused changes in the rivers had begun to deplete New England salmon runs by the early 1800s. The last two decades have brought a continuing decline, and today there are only eight Maine rivers in which native salmon are known to be reproducing.
There are other Atlantic salmon populations in some Canadian rivers, in hatcheries, and in aquaculture facilities. But very few salmon are still living successfully in the wild in the U.S.: in some of the eight Maine rivers, fewer than a dozen adults are returning to spawn each year. These remnant stocks are increasingly threatened by disease, the loss of habitat, and escapees from salmon farms.
The federal agencies responsible for protecting salmon determined last fall that the salmon in the eight Maine rivers are close to extinction and that they qualify for protection under the Endangered Species Act of 1973. In November, these agencies published a proposal to "list" these fish as endangered. The agencies are now taking public comment on that proposal. The comment period closes March 15, after which the agencies will be required to decide whether to list the salmon.
Atlantic salmon spawn in fresh water in the early autumn. The fertilized eggs remain in gravel on the stream bottom until spring, when they hatch and small fish called "fry" emerge. Fry quickly develop into "parr," a two-to-three inch-long fish that remains in freshwater. In New England rivers, it takes parr two or three years to grow large enough to develop into "smolts." In the smolt stage (approximately six inches long), the young salmon migrate downstream to the ocean.
Less is known about the animalís salt water life, but tagging studies have shown that young salmon migrate as far north as the Labrador Sea during their first summer in the ocean. After their first winter at sea, some of the salmon become sexually mature and return to their natal rivers to spawn. These are referred to as "1 sea-winter salmon" or "grilse," and they are much more common among Canadian stocks than among the salmon in Maine rivers.
Salmon that remain at sea for a second winter feed in coastal waters of Canada and Greenland and grow to approximately 30 inches in length and 8-15 pounds. Historically, these 2 sea-winter fish were caught in commercial gillnet fisheries off Nova Scotia, New Foundland, Labrador, and West Greenland. These fisheries have recently been closed or vastly reduced to protect the remaining stocks. There has also been recreational fishing for salmon in rivers and estuaries as they return to spawn. In recent years these were limited to catch-and-release fishing; in 2000 recreational fishing was closed altogether (except for an angling fishery on stocked fish farther south in the Merrimack River).
Atlantic salmon can return anytime from spring through fall, but the peak "run" is in June. Biologists think the fish use odors to find their home river. Spawning takes place from late October through November. Some salmon return to sea immediately after spawning, but most (80%) spend the winter in the stream and migrate back to the ocean in the spring.
A salmon that has spawned and is still in freshwater is called a "kelt" or "black salmon." When it returns to salt water and resumes feeding, it recovers its silver color and is known as a "bright" fish. A few of these spawners survive another one-to-two years at sea and return to the river as repeat spawners.