Run, Salmon, Run!

Resources & Background Info

An excellent source of information about the Salmon and environmental issues may be found at: CERES: Salmon--http://www.ceres.ca.gov/topic/salmon/salmon.html

Sites having to do with Endangered Species:

EcoNet Endangered Species Resources -- http://www.econet.apc.org/endangered/

ZooNet Endangered Species -- http://www.mindspring.com/~zoonet/endanger.htm

Endangered Species Lesson -- http://dsigw.gmu.edu/~tbarron/endangered.html

US FWS Endangered Species Recommended Internet Resources -- http://www.fws.gov/~r9endspp/sites.html

Endangered Species -- http://www.nceet.snre.umich.edu/EndSpp/Endangered.html

Environmental Organization WebDirectory - Wildlife:General Endangered Species -- http://www.webdirectory.com/Wildlife/General_Endangered_Species

SALMON BACKGROUND INFO: Coho (Silver) Salmon

Family: Salmonidae (Salmons)
Genus and Species: Oncorhynchus kisutch

Description: The body of the coho salmon is elongate and somewhat compressed. The head is conical. This species is dark metallic blue or blue green above, becoming slivery on the sides and belly. There are spots on the back.

The main distinguishing feature between the coho and the Chinook salmon is the color the gums at the base of the teeth. Chinook salmon have a blackish lining while coho has a white lining. Cohos also have back spots only on the upper part of the tail fin, whereas Chinook tail fins are completely covered with black spots.

Range: Coho salmon occur from Chamalu Bay, Baja California, to the Bering Sea and Japan.

Natural history: Cohos, as all salmon, are anadromous and spawn in fresh water. At spawning time, the males turn dusky green above and on their head, bright red on their sides and blackish below. The females turn a pinkish red on their side after they enter fresh water.

Coho salmon enter streams, move upstream, and spawn from September throught March. The bulk of spawning takes place from November throught January. Adult males enter streams when tehy are either 2 or 3 years old, but adult females do not return to spawn until 3 years old. Almost all female coho salmon will spawn at age 3. All coho salmon, whether male or female, spend their first year in the stream or river in which they hatch. All adults die after spawning.

Generally speaking, the larger the female the greater the number of eggs produced; however, numerous counts have been made that indicate most females will spawn from 1,00 to 3,500 eggs. The average number produced per female appears to be about 2,500.

Other Common Names: silver salmon, silversides, hookbill.

Largest Recorded: 38.5 inches; 31 pounds.

Citation: Marine Sportfish Identification, published by the California Department of Fish and Game, National Oceanic and Atmospheric Administration, and the University of California Marine Advisory Program

Teacher Background Information
The natures of rivers, coupled with the changes caused by the impact of humans on river environment has created a crisis for the fish that swim in the oceans and rivers of our world. Salmon are a unique species of fish which is able to live in both salt and fresh water during its extraordinary life cycle. Hatched in small, isolated pools, salmon spend from 1 to 2 years in fresh water before migrating out to the ocean. They then return 3 to 7 years later, depending upon the species. Many barriers await the male and female fish on their way to the spawning grounds. First are commercial and sport fishermen, not to mention harbor elephant seals and otters. Each year the salmon season is closely monitored in order to keep the population viable, but the salmon sits on the edge on endangerment. This is because of a combination of interacting human use problems, most if not all of them having serious political overtones. Overfishing, environmentally questionable logging practices, native American gillnetting, dams and diversions with ineffective fish ladders, industrial waste dumping, and encroaching human habitation and recreational use all contribute, and these aren't even the NATURAL enemies of the salmon: waterfalls and rapids, bears, foxes and predator birds. Many of these problems are surmountable, but only with real and consistant effort on the part of a broad base of the coastal community and with both federal assistance and regulation. This game os set up to illustrate the very difficult life the salmon has. Each player starts out with a certain number of salmon (100) and loses small amounts of them along the way. If they land on "hazard" squares, they must draw from a limited number of "salmon hazard cards" and can lose even more fish. Many of these hazards are natural, but others are created by humans. A Holling C. Holling book about salmon is a good one to go along with this lesson.

Since this unit has as its focus the interaction of land and water, it is important to emphasize with children how the land creates special challenges for the salmon on their run to spawn and the young salmon run to the ocean. Frist and foremost is the entrance to the river, its mouth and wave action. Depending upon tides, the shifting of sandbars, and other natural predators such as Ospreys or Heron, the mouth of the river is like a dangerous gauntlet. Later in the river, there is the danger when the water is murky that the salmon will take a wrong turn at a fork or the entrance to a side creek. In areas where there are rapids, many salmon simply exhaust themselves and never make it to the spawning area. Small waterfalls are a more serious problem, causing salmon to leap many feet in the air against the rushing water. Where humans have built dams, unless there are effective fish ladder systems, the salmon cannot continue and many die without spawning. Generally, salmon don't seek food while traveling upriver, but they are is poor to mean spirits, and will bite at insects simply out of frustration. This allows fisherman a chance to catch them as the salmon head upstream. At the top of waterfalls or in shallow rapids and riffles bear and birds wait for dinner.

Finally, the salmon survives to the spawning ground, the female to lay eggs and the male to layer the eggs with sperm, in clean gravel. The fish, battered from their trip, then expire, to supply food for insects and other aquatic critters. When the small fry break out of their sacs, these insects will be a welcome food supply. The need for clean spawning areas is most important. Too much silt, caused by topsoil being washed down from the hills around the spawning habitat, will lead to very survival rate for the fry. The degradation of salmon spawning habitat has generally been laid at the foot of poorly designed long term logging practices. Although in recent years these problems have begun to be honestly assessed and solutions have begun to be developed, most rivers are no longer wild, which adds to problems since the sedimention doesn't get cleaned up by powerful currents. Logging companies now must also create "buffer zones" of 100 to 200 feet in order that there be 1) enough land that erosion caused by cutting will be lessened and 2) that there be a shade cover near rivers, as temperature of the water is a very important variable. If the water is to hot in the spawning area it can be diasterous.

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