Salmon

Order: Salmoniformes

The appearance of salmon varies greatly from species to species. Some, like chum salmon, are silvery-blue in color, while some have black spots on their sides (Atlantic salmon) and others have bright red stripes (cherry salmon). Many species of salmon start their lives in fresh water, migrate to the ocean, then return to the very rivers or streams they were born in when it is time to reproduce, or “spawn”. Most of these species maintain one color when living in fresh water, then change color when they are in salt water.

Length Varies from species to species. The cherry salmon has an average length of around 20 inches, while the Chinook salmon has been known to reach almost 5 feet.
Weight 4 – 110 lbs depending on the species
Lifespan 2-8 years depending on the species

Diet

In general, young salmon eat insects, invertebrates and plankton; adults eat other fish, squid, eels, and shrimp. Unlike all other salmon, the sockeye salmon has a diet that consists almost entirely of plankton.

Population

It is difficult to estimate population numbers due to the large number of species and wide geographic range. However, population numbers in the Atlantic Ocean and in parts of the Pacific, as well as the Colorado River, have dropped drastically from what they were historically. In the Colorado River, for instance, salmon numbers are down to 3% of what they were during the time of Lewis and Clark.

Range

Salmon can be found in both the Atlantic and Pacific oceans as well as inland lakes like the Great Lakes.

Behavior

Most salmon are anadromous fish, meaning they are born in freshwater (rivers or streams), travel to and live much of their lives in salt water and return to freshwater to spawn. After spawning, all Pacific salmon and up to 50% of other species die within a few weeks. The salmon that do not die can spawn two or three more times.

There are a few species and subspecies of salmon, like the Danube salmon and the kokanee salmon, that spend their entire lives in fresh water and never migrate to the ocean.

Reproduction

When the female reaches the place where she will lay her eggs, she makes a depression in the riverbed with her tail, and then deposits her eggs in this depression. She waits for males to fertilize the eggs, then covers the depression and moves on to make another. Females will make as many depressions as it takes to lay all their eggs (up to seven depressions).

Threats

Damming of rivers is one major threat to salmon - they swim upriver to get to spawning areas, and are unable to proceed further when they reach a dam. Habitat loss, disease, overfishing, ocean and river warming and reduced food availability are other threats to the survival of salmon.

Legal Status/Protection

*Endangered Species Act

Atlantic salmon: Endangered in parts of Maine.

Chinook salmon: Endangered in parts of Washington and California; threatened in parts of Washington, California, and Idaho.

Coho salmon: Endangered in parts of California; threatened in parts of Oregon, California, and the Lower Columbia River

Sockeye salmon: Endangered in parts of Idaho; Threatened in parts of Washington.

Chum salmon: Threatened in parts of Oregon and Washington.

**IUCN Red List of Threatened Species

Cherry salmon: A subspecies of cherry salmon (Formosan land-locked salmon) is critically endangered; it is one of the rarest fish in the world.

*The Endangered Species Act requires the US federal government to identify species threatened with extinction, identify habitat they need to survive, and help protect both. In doing so, the Act works to ensure the basic health of our natural ecosystems and protect the legacy of conservation we leave to our children and grandchildren.

**The IUCN has for more than four decades been assessing the conservation status of species, subspecies, varieties and even selected subpopulations on a global scale in order to highlight taxa threatened with extinction, and therefore promote their conservation.