Saleiha+Mayer-Marks+Coho+Salmon


 * Coho Salmon** (//Oncorhynchus kisutch)//


 * Description**

Coho Salmon have dark metallic blue or greenish blacks with silver sides and a light-colored belly. They can reach lengths of 35 inches and can weigh up to 36 pounds, although the average weight is eight pounds and the average length is 28 inches.


 * Location and Habitat**

Coho salmon utilize freshwater, nearshore, and offshore environments during its lifecycle. The coho salmon spend the first 1-2 years of their lives living in streams and small freshwater tributaries until they are full grown coho salmon. Thier remainder of their adult lifespan is normally spent in the Pacific Ocean between the Monterey Bay in California to Pont Hope in the Chukchi Sea except when the salmon return back to the tributaires to reproduce.




 * Niche**

During the fry life stage, the coho feed on aquatic insects, zooplankton, and small fish for their survival. As soon as they are large enough, coho salmon begin to feed on smelt and alewives. But, when the coho salmon reach the estuaries they become prey for a numerous amount of predators. These predators include predatory birds, such as the eagle and falcon, sea lampreys, and many predatory fish. Competition for food also takes a hit on the coho population as the coho compete with the chinook salmon and steelheads for food. When coho salmon die, thier bodies are decomposed and become nutrients for other plants and living organisms.


 * Reproduction**

During the reproduction stage, the jaws and teeth of the male Coho salmon become hooked and they develop bright red sides, bluish green heads and backs along with dark spots, and dark bellies. Coho salmon enter spawning streams from late September through January, during which the female coho salmon lay between 1,500 to 5,700 eggs (depending on their size) in gravel beds. After spawning both adult fish soon die, and the eggs are left alone to survive various elements, such as birds, insects, and other fish. The eggs take roughly 2 to 4 months to develop, so by next spring the eggs hatch. These salmon go through five different stages; the alevin, fry, smolt, ocean salmon, and spawning salmon phrases. The alevin stay in the gravel for 2-3 weeks. When the alevin leave the protection of the rocks they progress into fry. By the spring of the next year the fry have progressed into smolt, and live in tributaries near the ocean with a mixture of fresh and saltwater. When the smolts' gills have adjusted to the saltwater, they swim to the ocean and become ocean salmon. After one year at sea, the ocean salmon swim back to the streams ready for spawning.




 * Population**

Although the coho salmon spawn in tributaries, most coho salmon stocks are maintained by fish culture and stocking because there is not enough streams avaliable to produce the amount of coho that the humans need. Even though the coho stock in the U.S. is decreasing, coho from Chile has increased so much that the coho population has increased overall on a worldwide scale. In the United States, there are currently seven Evolutionary Significant Units (ESUs) located in Washington, Oregon, and California. Four of these ESUs are listed under the U.S. Endangered Species Act. This is due to many natural and man-made conditions that has caused a downfall to the coho population in the U.S.


 * Works Cited**

"Coho Salmon." Essential Fish Habitat. Pacific Coast Marine Habitat Program, 16 Dec. 1996. Web. 14 Oct. 2009. @http://www.psmfc.org/habitat/edu_coho_facts.html

"Coho Salmon (Oncorhynchus kisutch)." Department of Natural Resources. Michigan Government, 2001-2009. Web. 14 Oct. 2009. @http://www.michigan.gov/dnr/0,1607,7-153-10364_18958-45666--,00.html

USFWS Staff. "Coho Salmon." Fairbanks Fish & Wildlife Fielf Office. U.S. Fish & Wildlife Service, 4 Mar. 2009. Web. 14 Oct. 2009. @http://cybersalmon.fws.gov/coho.htm