The salmon is part of a family of fish called salmonidae that includes trout and whitefish. They live in the North Atlantic and Pacific Oceans. There are five species of Pacific salmon and one species of Atlantic salmon. Their appearances differ from species to species. The chum salmon are silvery blue, while others like the Atlantic salmon have black spots on their sides. The cherry salmon has red stripes. Most salmon maintain one color in freshwater and change color in salt water.
FACT 1: Salmon are anadromous. This means that they are born in freshwater, migrate to the sea, and return to freshwater to spawn (lay eggs). Salmon migrate up to 3,200 miles to spawn. They do not eat during this migration but get the energy from stored body fat.
FACT 2: When the female reaches the place where she will lay her eggs (called roe), she makes a depression in the river bed with her tail. She deposits her eggs in this nest (called a redd). Once the male fertilizes the eggs, the female covers them up. A female can have between 2,500 and 7,000 eggs. A salmon pair can make up to seven redds.
FACT 3: Salmon are called fry when emerging from the eggs. When they grow to about the length of a human finger, they are called fingerlings. As they begin their seaward migration, they are called smolt. Smoltification is the process of bodily adjustment that young salmon undergo in order to be able to live in salt water.
FACT 4: Young salmon stay in the river for one to three years of their lives. They live on insects, invertebrates, and plankton. Adult salmon eat other fish, squid, eels, and shrimp.
FACT 5: After spawning, all Pacific salmon and up to 50% of Atlantic salmon die within a few weeks. Salmon that do not die can spawn two or three more times.
FACT 6: Some salmon live up to 13 years. Some, like the Chinook Salmon, can reach a length of almost 5 feet and can weigh about 60 kg. Adult salmon are excellent jumpers and can ascend rapids to reach fresh water.
FACT 7: Over the years, the number of salmon in the rivers has been steadily declining. Many species have been declared by the US government to be either endangered or threatened. The causes of the decline in numbers are many. Salmon need cool, clean water with a maximum water temperature of 68 to 75 degrees Fahrenheit. The warming of the ocean waters, caused by climate change, affects the health of salmon, making them more susceptible to disease. Water pollution also affects the salmon. The building of dams on the rivers impedes salmon migration, thereby affecting reproduction. Excessive fishing is also a cause of depleted salmon stock.
FACT 8: In the 1870s, the Federal Government started a massive California hatchery program to reverse the decline of wild salmon. In the hatchery, eggs were incubated; and the fry or fingerlings were released into the river. This experiment did not increase the number of salmon; instead the salmon numbers further declined, and hatcheries are now banned on the Pacific Coast.
FACT 9: The hatcheries failed because they released too many fingerlings into the water. The hatchery-bred fingerlings had to compete with the wild salmon for the limited food resources. Both the hatchery-bred and the wild salmon suffered. Interbreeding of hatchery-bred and wild salmon interferes with the process of natural selection. It reduces resistance and dilutes local adaptations.
FACT 10: Smoked salmon is a rather pricey delicacy in North America and Europe. This salmon comes from hatcheries in Norway, Scotland, Ireland, and the East Coast of Canada. In the Pacific regions, wild salmon is used.