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Abandoned Mine Drainage’s Impacts The Impact of AMD to Life in Streams Lessons Prepared by Trout Unlimited With Funds from Pennsylvania Department of Environmental Protection What are Some Impacts of Abandoned Mine Drainage? Impacts of AMD to a Stream • Chemical – Decreased pH – Increased dissolved metal concentrations • Fe, Al, Mn – High sulfate concentrations • Physical – Increased turbidity from soil erosion – Covering stream substrate by precipitated metal compounds Benthic Macroinvertebrates • Used as biological indicators for water quality – Can be better than a water sample because it shows the daily impacts of AMD not just the momentary chemistry of one sample – Different species have varying degrees of sensitivity to pollutants • Unaffected streams (clean streams) generally have a variety of species with representatives of all insect orders Some Pollution Tolerant Groups of Benthic Macroinvertebrates • • • • • • Earthworms (Tubificidae) Midge larvae (Chironomidae) Alderfly larvae (Sialis) Fishfly larvae (Nigronia) Cranefly larvae (Tipula) Caddisfly larvae (Ptilostomis) All photos provided by Trout Nut. http://www.troutnut.com/ EPT Taxa • Insects classed in the orders Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). • Generally intolerant to pollution – Some caddisflies and stoneflies are tolerant of dilute AMD Photos are left to right: stonefly, mayfly, and caddisfly. Provided by Trout Nut http://www.troutnut.com/ Impacts of AMD on Benthic Macroinvertebrates • Reduction in diversity • Reduction in total numbers (abundance) • Changes in community structure (increased abundance of pollution tolerant organisms) pH • Most organisms have a defined range for pH • Low pH affects the balance of sodium and chloride ions in the blood • How impaired a stream is can be determined by the diversity and quantity of benthic macroinvertebrates found in the stream – Some macroinvertebrates can handle a lower pH and higher concentrations of metals – Mayflies are one of the most sensitive groups of aquatic insects to low pH pH’s Effects on Macroinvertebrates Stoneflies (Some Species) Caddisflies (Some Species) Craneflies Blackflies Few if any Macroinvertebrates 3.5 4.0 Tubiflex Worms Midge Alderflies Fishflies Diving Beetle Water Boatman 4.5 5.0 5.5 6.0 Mayflies Elmid Beetles Waterpennies Riffle Beetle Most aquatic insects pH’s Effects on Fish Creek Chubsucker Largemouth Bass Chain Pickerel Golden Shiner White Sucker Brown Bullhead Pumpkinseed Bluntnose Minnow Blacknose Dace Brook Trout Creek Chub Ohio Lamprey Yellow Perch Brown Trout Longnose Dace Margined Madtom Tessellated Darter Slimy Sculpin Silverjaw Minnow Redside Dace River Chub Spotfin Shiner Common Shiner Spottail Shiner Silver Shiner Pearl Dace Rosyface Shiner Green Sunfish Mimic Shiner Northern Hogsucker Rock Bass Smallmouth Bass Greenside Darter Fantail Darter Johnny Darter Banded Darter Blackside Darter 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.6 5.7 5.8 5.9 6.0 6.1 6.2 6.3 6.4 6.5 Metals • Metals are more toxic to aquatic life at lower pH • Some fish, like brook trout, are tolerant to lower pH, but the addition of metals decreases that tolerance – For example, a pH < 5.5 and dissolved aluminum concentrations >0.5 mg/L will generally eliminate all fish and many macroinvertebrates. Iron and Aluminum seen in a stream all can be deadly to fish and other life. Provided by TU Staff. Metals • Metals like iron and aluminum can precipitate out of the water • These precipitates have negative impacts to the aquatic ecosystem: – Precipitate may coat the gills and body surfaces of benthic macroinvertebrates or fish – Smother eggs (decreases reproductive success) – Cover stream bottom, fill in crevices in rocks, and/or make substrate unstable (decreases available habitat for benthic macroinvertebrates and fish) Impacts AMD has on Brook Trout • Low pH levels • AMD impaired streams restrict respiratory action create a toxic barrier • Metal precipitates can between streams and get caught in their gills their headwaters • Increased osmotic • Isolated populations pressure and decreased result in inbreeding oxygen • Trout will have to relocate quickly or suffocate. Impacts to a Stream System B. A. D. This is a system of streams. The color change shows when headwater streams add to the system If stream C.ofwas impaired how many isolated How much the system would be affected if populations stream A Which stream would cause the least impairment overall? would create? becamethis impaired? Impacts of AMD Outside the Stream • Environmental: – Dead Zones are made as AMD flows over the soil – As vegetation is removed herbivores relocate due to lack of food – Lack of fish and other aquatic food sources can cause other animals to move away from areas – Nutrients that normally are captured and held by plant life are allowed to pass freely down stream leading to nutrification Impacts of AMD Outside the Stream • Economic: – Proximity to an impaired stream has a direct affect on property values – Money is spent to provide clean drinking water in these areas – Fishing revenue is lost – Concrete structures as well as other materials that contact AMD can be weakened and require replacement more often