Atlantic salmon is a species of fish found in the northern Atlantic Ocean and in rivers that flow into the Atlantic. Most Atlantic salmon follow an anadromous fish migration pattern, in that they undergo their greatest feeding and growth in salt water, but adults return to spawn in native freshwater streams where the eggs hatch and juveniles grow through several distinct stages.
Most Atlantic salmon follow an anadromous fish migration pattern, in that they undergo their greatest feeding and growth in salt water, but adults return to spawn in native freshwater streams where the eggs hatch and juveniles grow through several distinct stages.
Atlantic salmon do not require salt water, however, and numerous examples of fully freshwater ("landlocked") populations of the species exist throughout the Northern Hemisphere.
The colouration of young Atlantic salmon does not resemble their adult stage. While they live in freshwater they have blue and red spots. While they mature they take on a silver blue sheen. When they are adults the easiest way of identifying them is by the black spots predominantly above the lateral line, although its caudal fin is usually unspotted. When they reproduce males take on a slight green or red colouration. The salmon has a fusiform body, and well developed teeth. All fins, save for the adipose, are bordered with black.
Around the North Atlantic, efforts to restore salmon to their native habitats are underway and there is some slow but steady progress. Restoration and protection of the habitat itself is key to this process but issues of excessive harvest and competition with farmed and escaped salmon are also primary considerations. In the Great Lakes, Atlantic salmon have been introduced successfully, but the actual percentage of salmon reproducing naturally is very low. Most are stocked annually. Atlantic salmon were native to Lake Ontario but were extirpated by habitat loss and overfishing in the late 19th century. The state of New York has since been annually stocking its adjoining rivers and tributaries with the fish and in many cases do not allow active pursuit of the species.
After hatching, young salmon begin a feeding response within a couple days. After the yolk sac is absorbed by the body, they begin to hunt. Juveniles start with tiny invertebrates, but as they mature they may occasionally eat small fishes. During this time they hunt both in the substrate, and also those in the current. Some have been known to also eat salmon eggs. The most commonly eaten foods include caddisflies, blackflies, mayflies, and stoneflies.
In adulthood, fish feed on much larger food: Arctic squid, sand eels, amphipods, Arctic shrimp, and sometimes herring. During this feeding time the fish's size increases dramatically.
The Atlantic Salmon goes by other names such as landlocked salmon, ouananiche.
