Pacific Salmon Research Paper

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Salmon Only Have One Thing To Say About Upstream Migrations: Dam! OR The Impacts of Dams on Spawning Populations of Pacific Salmon Introduction When humans first arrived in the Pacific Northwest they saw great potential in the rivers for harnessing their power to provide energy for them by spinning waterwheels or, later, turbines. Before the dams were built there was some thought about how they would impact the wildlife and surrounding natural environment but it was not fully explored until later times. As it happens, dams do greatly impact rivers and the animals living in them. One of these was the Pacific salmon. The objective of this paper is to examine both the direct and indirect impacts that dams have on Pacific salmon and their surrounding…show more content…
Most directly, the fish act as a vital food source for bears, eagles, and other carnivores, as well as insects and detrivores. For hibernating animals like bears, the arrival of spawning salmon is especially important because of the rich source of energy that will help them through the winter to spring. An indirect way that salmon are vital to the environment is that when they decompose or have been digested by a predator, vital nutrients including phosphorous and nitrogen are returned to the soil (Gende, S. M., Edwards, R. T., Willson, M. F., & Wipfli, M. S.). For almost as long as there have been humans we have been changing rivers, and dams have been a big impact on the environment. There are many reasons why dams are built. They create reservoirs of still waters that have the potential energy to drive turbines to create electricity, reservoirs can be used for drinking water and recreation like boating and fishing, and dams can regulate otherwise unpredictable rivers. Direct Impacts of Dams on…show more content…
A selection of them includes fish ladders, spillways, transporting juveniles, and dam removal. To start off with are fish ladders which are, as the name implies, a kind of stairway for the fish to use to pass over a dam. Fish are attracted to the opening of the ladders by a current which leads to the first step of the ladder. By either jumping or swimming forward, each subsequent step leads the fish higher and higher until they are above and away from the dam. Fish ladders have been remarkably effective at bringing salmon past dams, exemplified at the Landsburg Dam on the Cedar River in Washington. Before a fish ladder was installed there in 2003, coho and chinook salmon were blocked from migrating further upstream but they were spotted in pools past the dam not long after its construction (Kiffney, P. M., Press, G. R., Anderson, J. H., Faulds, P., Burton, K., & Riley, S. C.). When a blocked river receives a fish ladder, it takes between one and five years for a self-sustaining population to become established upriver of it (Pess, G. R., Quinn, T. P., Gephard, S. R., & Saunders, R.). A caveat with fish ladders is that they only really work with adults migrating upstream; they do not provide a good solution for smolts migrating downstream because they are designed to be one

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