9870092 Vaughn The freshwater mussel (Bivalvia: Unionidae) fauna of North American streams is the most diverse in the world, but is highly threatened and declining at an alarming rate. The consequences of this catastrophic decline of an entire fauna go beyond the loss of species, because mussels serve critical roles in the functioning of riverine ecosystems. Thus, the current decline in mussel species also represents a loss of critical habitat and food resources for the remaining aquatic fauna, and may alter the ecosystem functioning in many North American rivers. In addition, there are likely benthic macroinvertebrates that have coevolved with mussel assemblages, are specifically dependent on them, and thus may also be declining. The Ouachita Uplands, in central and western Arkansas and southeastern Oklahoma, U.S., represent one of the last strongholds of freshwater biodiversity in North America and may represent one of the few areas where conservation of an intact mussel fauna may be possible. Freshwater mussels and associated benthic macroinvertebrates will be surveyed in the major river systems of the Ouachita Uplands over a period of three field seasons. Mussels and benthic macroinvertebrates will be quantitatively sampled and environmental parameters will be measured at each site. Mussel and benthic macroinvertebrate voucher specimens will be deposited in the Oklahoma Museum of Natural History and the Illinois Natural History Survey (crayfish). Mussel tissue samples will be deposited with the U.S.G.S. Leetown Science Center genetic tissue repository and the Texas Parks and Wildlife Heart of the Hills Research Station. Mussel and benthic macroinvertebrate data will made available on the internet. The data collected will be applicable to a multitude of conceptual problems in biology, many of which have important conservation implications. In addition, the data will provide a baseline for monitoring these areas in the future, particularly in response to the impending zebra mussel invasion.
