General Information

The Atlantic Salmon (Salmo salar) is an endangered species of fish with its only remaining American habitat in the Gulf of Maine. Outside of America, they live in the North Atlantic Basin, from eastern Canada to Greenland to western Europe. They form a key part of ocean ecology. Young Atlantic salmon feast on insects, invertebrates, and plankton; adults eat capelin. In return, Atlantic salmon provide food for bass, ospreys, herons, and otters in their juvenile form, and sharks, seals, and whales in their maturity.

The Life of an Atlantic Salmon

Atlantic salmon live between three and seven years. Their life starts out as one of 7,500 eggs laid in a ditch dug out in coarse gravel called a “redd” in a river of moving water in fall. The eggs hatch tiny salmon (called alevin), and in spring 15-35% of the alevin swim out as fry. Those fry require cover in the form of rocks and vegetation to advance to their next stage: parr. At about two inches long, these freshwater Atlantic salmon are brown or bronze, with dark vertical stripes and red and black spots to aid effective camouflage. Over the next two to three years, the salmon grow to between 2 and 3 feet long and become smolts. The process to becoming a smolt entails a change in their gills and organs so that they can travel with a shoal from their river out to near the surface of the Atlantic, and a loss of their bronze coloration and vertical stripes in favor of a silver appearance, to blend in with the Atlantic environment. For Maine salmon, this happens around the period from April to June, where they then spend a year or two achieving maturity around the Labrador Sea or Greenland. After maturity (i.e, becoming a kelt), the salmon revert to their bronze coloration and visit Maine rivers for the summer. They rest in deep, cool shaded resting pools, and dig a redd to spawn eggs in. They return to the Atlantic, becoming silver again. Some salmon repeat this spawning process after regaining their weight in the ocean, but this has become less common over the years.

How to restore Atlantic Salmon

By removing dams that restrict Atlantic salmon to 8% of their historic freshwater habitats and using captive breeding, Maine can both create new Atlantic salmon habitat and breed Atlantic salmon to fill the rivers, restoring Maine’s historical ecosystem. In addition, cooperation through the North Atlantic Salmon Conservation Organization will allow restrictions in Greenland fishing of American salmon, increasing the Atlantic salmon population more. It is possible that some salmon would use the Megunticook for spawning if they had easier access to the river.

Sources

Atlantic salmon (Protected). (n.d.). NOAA. https://www.fisheries.noaa.gov/species/atlantic-salmon-protected

Fun facts about amazing Atlantic salmon. (n.d.). NOAA. https://www.fisheries.noaa.gov/national/outreach-and-education/fun-facts-about-amazing-atlantic-salmon

Northeast Region Web Development Group. (2019, March 28). Maine Field office. U.S. Fish and Wildlife Service. https://www.fws.gov/mainefieldoffice/Atlantic_salmon.html