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AN INTEGRATIVE APPROACH TOWARDS UNDERSTANDING ECOLOGICAL RESPONSES TO DAM REMOVAL: THE MANATAWNY CREEK STUDY 1
Author(s) -
BushawNewton Karen L.,
Hart David D.,
Pizzuto James E.,
Thomson James R.,
Egan Jennifer,
Ashley Jeffrey T.,
Johnson Thomas E.,
Horwitz Richard J.,
Keeley Melissa,
Lawrence Joy,
Charles Don,
Gatenby Catherine,
Kreeger Daniel A.,
Nightengale Tim,
Thomas Roger L.,
Velinsky David J.
Publication year - 2002
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.2002.tb04366.x
Subject(s) - dam removal , river ecosystem , environmental science , hydrology (agriculture) , benthic zone , lake ecosystem , habitat , water quality , ecology , stream restoration , sediment , channel (broadcasting) , sediment transport , restoration ecology , geology , biology , paleontology , geotechnical engineering , engineering , electrical engineering
Dam removal has been proposed as an effective method of river restoration, but few integrative studies have examined ecological responses to the removal of dams. In 1999, we initiated an interdisciplinary study to determine ecological responses to the removal of a 2 m high dam on lower Manatawny Creek in southeastern Pennsylvania. We used an integrative monitoring program to assess the physical, chemical, and biological responses to dam removal. Following removal in 2000, increased sediment transport has led to major changes in channel form in the former impoundment and downstream reaches. Water quality did not change markedly following removal, probably because of the impoundment's short hydraulic residence time (less than two hours at base flow) and infrequent temperature stratification. When the impoundment was converted to a free flowing reach, the composition of the benthic macroinvertebrate and fish assemblages in this portion of Manatawny Creek shifted dramatically from lentic to lotic taxa. Some fish species inhabiting the free flowing reach downstream from the dam were negatively affected by large scale sediment transport and habitat alteration following dam removal, but this appears to be a short term response. Based on our observations and experiences in this study, we provide a list of issues to evaluate when considering future dam removals.