HR: 1330h
AN: NB33G-03    [Abstracts]
TI: Long Wall Mining Subsidence and Fluvial Stream Changes: an Ecological Perspective
AU: * Spear, R
EM: rspear@state.pa.us
AF: PA Department of Environmental Protection, 400 Waterfront Drive, Pittsburgh, PA 15222 United States
AU: Proch, T
EM: tproch@state.pa.us
AF: PA Department of Environmental Protection, 400 Waterfront Drive, Pittsburgh, PA 15222 United States
AB: Long wall mining is a high efficiency underground coal extraction technique that removes large panels of coal and causes immediate subsidence of the overburden. Surface subsidence may vary between 0.3 meters and 2 meters depending on the depth of the coal seam. Fractures in the overburden allow perched water tables to drain to greater depths and dries up their associated springs. Base flow in headwater streams is often eliminated. Subsidence also changes the physical characteristics of streams. Typical riffle pool sequences are replaced with long pools and glides. Benthic invertebrate and fish community assemblages reflect the physical habitat changes. EPT invertebrate taxa are replaced with Odonates and Diptera larvae associated with glide/pool habitat. Fish community diversity is negatively impacted. Diverse riffle dwelling assemblages are replaced and dominated by increasingly homogenous pool dwelling fish communities. Stream subsidence effectively increases the stream order without increasing its size or flow regime.
DE: 9800 GENERAL OR MISCELLANEOUS
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly