Effects of sediment on fish and their habitat |
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Fisheries and Oceans - Pacific Region - 2000/01 E - Placer Mining in the Yukon Territory
"Following their review EIFAC (1964) deduced the following criteria for the protection of fisheries resources: <25 parts per million* (ppm) of suspended solids - no evidence of harmful effects on fish and fisheries; 25 - 80 ppm - it should be possible to maintain good to moderate fisheries, however the yield would be somewhat diminished relative to waters with <25 ppm suspended solids; 80 - 400 ppm - these waters are unlikely to support good freshwater fisheries; and 400 ppm suspended solids - at best, only poor fisheries are likely to be found."
The levels of risk and the corresponding concentrations of sediment follow:
Sediment increase (mg·L-1) Risk to fish and their habitat
0 No risk
<25 Very low risk
25 - 100 Low risk
100 - 200 Moderate risk
200 - 400 High risk
>400 Unacceptable risk
"Following their review EIFAC (1964) deduced the following criteria for the protection of fisheries resources: <25 parts per million* (ppm) of suspended solids - no evidence of harmful effects on fish and fisheries; 25 - 80 ppm - it should be possible to maintain good to moderate fisheries, however the yield would be somewhat diminished relative to waters with <25 ppm suspended solids; 80 - 400 ppm - these waters are unlikely to support good freshwater fisheries; and 400 ppm suspended solids - at best, only poor fisheries are likely to be found."
The levels of risk and the corresponding concentrations of sediment follow:
Sediment increase (mg·L-1) Risk to fish and their habitat
0 No risk
<25 Very low risk
25 - 100 Low risk
100 - 200 Moderate risk
200 - 400 High risk
>400 Unacceptable risk
Impact of suction dredging on water quality, benthic habitat, and biota in the Fortymile River and Resurrection Creek, Alaska |
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US Environmental Protection Agency Region 10 Seattle, Washington - Prepared By: Todd V. Royer, Aaron M. Prussian, and G. Wayne Minshall Department of Biological Sciences Idaho State University - Final Report April 1999
"The second component of this project was to examine the effects of recreational suction dredging on smaller streams in Alaska. In 1997, sampling was conducted on a single site on Resurrection Creek, a designated recreational mining stream on the Kenai Peninsula. In 1998, sampling was conducted on Resurrection Creek, as well as on two additional streams known to be popular for recreational dredging. The Chatanika River was sampled at a location north of Fairbanks, and Cooper Creek was sampled near its confluence with the Kenai River. The results from Resurrection Creek indicated that there was no difference in the macroinvertebrate community between the mining area and the locations downstream of the mining area, in terms of macroinvertebrate density, taxa richness, and EPT richness. In general, our results are in agreement with other studies that have found only localized reductions in macroinvertebrate abundance in relation to recreational suction mining."
"The second component of this project was to examine the effects of recreational suction dredging on smaller streams in Alaska. In 1997, sampling was conducted on a single site on Resurrection Creek, a designated recreational mining stream on the Kenai Peninsula. In 1998, sampling was conducted on Resurrection Creek, as well as on two additional streams known to be popular for recreational dredging. The Chatanika River was sampled at a location north of Fairbanks, and Cooper Creek was sampled near its confluence with the Kenai River. The results from Resurrection Creek indicated that there was no difference in the macroinvertebrate community between the mining area and the locations downstream of the mining area, in terms of macroinvertebrate density, taxa richness, and EPT richness. In general, our results are in agreement with other studies that have found only localized reductions in macroinvertebrate abundance in relation to recreational suction mining."