Effects of acid mine drainage on fish and macroinvertebrates of the Tioga River, Pennsylvania and New York

Acid water from abandoned coal mines in the vicinity of Morris Run and Blossburg, Pa., severely alter the aquatic environment of the Tioga River. From Morris Run to Crooked Creek, a reach of 19 miles, the river bed is influenced by a smothering blanket of heavy metal precipitates and highly acidic water. Biologically, this reach of the river is devoid of fishlife and nearly devoid of benthic macroinvertebrates. Downstream from Crooked Creek the water quality and biota are slowly restored. At Presho, N.Y., the river again supports an abundant and diversified population of fish and bottom-dwelling organisms.