Do Dams Make A Difference? Similar Survival Rates For Pacific Salmon In Fraser And Columbia Rivers
According to the original text, researchers from Canada and the United States had conducted an amazing discovery which stated that a number of those in danger of extinction, specifically the Pacific salmon stocks, had been seen existing among rivers having hydroelectric dams and among rivers having no dams. The research had been the first of its type. It had been conducted by one international group of the scientists which further included several researchers coming from the British Columbia University. The original text mentioned that the group made a comparison with regard to the different enduring rates of the out-migrating, young spring Chinook as well as steelhead salmon, studied with simple microscopes, which starting from river basins. Examples of these were the rivers of Snake as well as Columbia which were considered to be immensely dammed. With the use of technology which had lately been obtainable, the research group had electronically labeled juvenile salmon.
Such could be examined further with simple microscopes. They had also made a monitoring with regard to the expedition from the freshwaters towards the ocean by way of a huge-scale audio telemetry system. The latter had been named POST or Pacific Ocean Shelf Tracking array. Erin Rechisky had been one of the authors of this research undertaking. According to him, it was really surprising that this Fraser River salmon populace had an inferior endurance compared to those populations of the study of the Columbia River. It was further emphasized that there had been an unsatisfactory proof towards reaching any kind of conclusion. It was pretty clear that dams were of no good to salmons. However, what had been uncertain was if this Fraser River contained any problem which slashed the survival of salmon towards that of one solidly dammed river, among other things.
Simple microscopes had been very helpful in this study. It was in modern years that audio tags became tiny enough for the scientists towards implanting such into young salmon as well as trace them during their migration downstream. The said innovations made them capable in the gathering of data upon salmon smolts, studied with simple microscopes, at the Fraser River. Prior to that, what was possible was the measurement of juvenile endurance wherein the salmon had been taken from dam bypasses such as those seen in the Rivers of Columbia and Snake. This lower Columbia as well as the minor Snake Rivers presently had eight chief hydroelectric dams shared. Throughout the latter part of the 1930s wherein the initial dams started in going up, the rates of survival of the salmon started towards plummeting and at the same time, hitting highs of mortality throughout the years 1960s as well as 1970s because of a mixture of the warmer waters, some turbines which grind fish as well as contemporary predators.
Ever since that time, the government of the United States had made an investment in chief measures of restoration towards the improvement of the survival rates of the salmon. Contemporary efforts of conservation had paid attention on aiding smolts pass by way of some hydropower system. Also, this research team made it a point to make a clarification with the future undertakings with the use of the POST technology.
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http://www.sciencedaily.com/releases/2008/10/081028074430.htm
