Lake-wide Benthic Surveys in Lake Michigan in 1994-95, 2000, 2005, and 2010 PDF Download

Author: T. F. Nalepa
Publisher:
ISBN:
Category : Benthos
Languages : en
Pages : 21

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Book Description
"This technical report provides basic results of lake-wide, benthic surveys conducted in Lake Michigan in 1994-1995, 2000, 2005, and 2010 to assess temporal trends in the native amphipod Diporeia spp., the zebra mussel (Dreissena polymorpha), and the quagga mussel (Dreissena rostriformis bugensis). These surveys are an expansion of a continuing, monitoring program in the southern basin of the lake conducted by the Great Lakes Environmental Research Laboratory (GLERL) that examines trends in the abundance and composition of the entire macroinvertebrate community (Nalepa 1987, Nalepa et al. 1998). The GLERL program was initiated in 1980 with the original intent of assessing the response of the benthic community to phosphorus abatement efforts in the mid-1970s (Nalepa 1987). However, after D. polymorpha became established in the southwestern portion of the lake in 1989 (Marsden et al. 1993), the monitoring program detected several dramatic changes in the benthic community in the early 1990s. Diporeia began to systematically disappear, and D. polymorpha rapidly expanded and soon became dominant in the nearshore region (Nalepa et al. 1998). To determine if changes in the southern basin were also occurring throughout the lake, the monitoring program was greatly expanded in 1994-1995. Benthic sampling in these two years was conducted jointly with several other sampling programs in Lake Michigan: Environmental Monitoring and Assessment (EMAP) and Lake Michigan Mass Balance (LMMB). After 1994-1995, lakewide monitoring of Diporeia and Dreissena populations continued at 5-year intervals (i.e., 2000, 2005, and 2010) as part of a regular monitoring program at GLERL that supplemented the continued effort in the southern basin"--Introduction.