Fish and food organisms in acid mine waters of Pennsylvania

Abstract

The three parts of this project relate respectively to the three objectives: develop a rapid and non-lethal bioassay for acid water using changes in utilization of cover and activity of fish, determine the effect of different levels of acid mine drainage on the presence or absence of fish populations in the watersheds of Pennsylvania, determine the median tolerance limits to low levels of pH of five aquatic insects chosen on the basis of their wide occurrence and common association in soft-water streams. Analysis of variance revealed there was no relationship between cover utilization and pH levels or between activity and pH levels for four species of fish (smallmouth bass, longnose dace, rock bass and brook trout). The failure of cover utilization and activity to reflect changes in water quality conditions makes this bioassay technique as tested unsuitable for the establishment of water quality criteria. In part II of the project it was found that common fish species normally distributed over several watersheds were absent where there was severe acid mine drainage. Of the 116 species of fishes found, 10 species exhibited some tolerance to acid mine drainage (values of pH 5.5 or less). An additional 38 species were found atmore » pH values between 5.6 and 6.4 with the remaining 68 species at pH levels above 6.4. Severe degradation occurred at pH levels between 4.5 and 5.6. In part III all five aquatic species survived exposure for four days to pH levels from 6.5 to 4.0. The 96-hour TLm values ranged from 3.31 for the most sensitive animal, Stenonema sp., to 1.72 for the most tolerant insect, Nigronia fasciata.« less