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Environmental Factors: Numerous factors of the environment can significantly alter the life of the trout. They can be affected by the population other different trout. Other species, such as beaver, can have a large influence upon trout. The frequency and abundance of food or changes in water chemistry all effect the abundance and reproduction of trout in City Creek. Water
quality can affect the trout directly or indirectly. Alterations in
water temperature, oxygen levels, salinity and chemical nutrients, can
result in the adaptation to these new conditions, or altogether eliminate
the species. For example, trout may enter the polluted Jordan river from
City Creek, but it is unlikely they will survive there. Natural disturbances
can affect the habitat of the trout on the City Creek watershed. Floods
can alter the structure of the streambed. They may tear away valuable
covers that protect the trout, increase the erosion-caused sediment in
streams, scoured gritt on sediment can cover the gravel beds that trout
use for spawning, if it occurs during the incubation period, it will
destroy the eggs, the next generation of fish (Schnell and Stolz 173).
Since frequent floods can damage the habitat for almost all organisms in
the stream, the trout as a predator is affected. The 1983 flood of City
Creek Canyon, as described in the introduction, affected the stream
structure as explained above. During a flood, trout
swim into severely flooded backwaters. Once the water begins to lower, the
fish become stranded in these pools and die. Flooding in City Creek is
infrequent. The steep nature of the canyon does not provide a cut for
backwaters. Schnell and stolz (1991) were ablr to show that floods in
Minnesota reduced the number of Brook trout, which allowed them to expand their
population ranges, thus changing the trout species mix. The presence of Beaver is important to the habitat. When beaver construct dams, water builds up and creates pools. Silt and nutrients are trapped behind the dams causing growth and vegetation.These pools have slow moving currents, which are favorable to the trout. They tend to move to these areas. One major problem on the watershed is that during dry years the snowmelt does not provide enough runoff or ground water storage for beaver ponds. The ponds get converted to willows or grassy medows during the succesional process (Potts interview). |