JGLR Special Topic

J. Great Lakes Res. 31(sup1)
Internat. Assoc. Great Lakes Res., 2005
Marlene S. Evans, ed.

NEARSHORE AND COASTAL HABITATS OF THE LAURENTIAN GREAT LAKES
Scudder D. Mackey and Reuben R. Goforth, guest eds.

J. Great Lakes Res. 31(sup1):45-63.
Internat. Assoc. Great Lakes Res., 2005
Type: Article
Special Topic

An Evaluation of Effects of Groundwater Exchange on Nearshore Habitats and Water Quality of Western Lake Erie

Sheridan K. Haack¹, Brian P. Neff¹, Donald O. Rosenberry², Jacqueline F. Savino³ and Scott C. Lundstrom², ¹United States Geological Survey, 6520 Mercantile Way, Suite 5, Lansing, Michigan, 48911; ²P.O. Box 25406, Denver Federal Center, MS 913, Lakewood, Colorado, 80225; ³USGS Great Lakes Science Center, 1451 Green Road, Ann Arbor, Michigan, 48105

ABSTRACT: Historically, the high potentiometric surface of groundwater in the Silurian/Devonian carbonate aquifer in Monroe County, MI resulted in discharge of highly mineralized, SO₄-rich groundwater to the Lake Erie shoreline near both Erie State Game Area (ESGA) and Pointe Mouillee State Game Area (PMSGA). Recently, regional groundwater levels near PMSGA have been drawn down as much as 45 m below lake level in apparent response to quarry dewatering. From August to November of 2003, we conducted preliminary studies of groundwater flow dynamics and chemistry, shallow lake water chemistry, and fish and invertebrate communities at both sites. Consistent with regional observations, groundwater flow direction in the nearshore at ESGA was upward, or toward Lake Erie, and shallow nearshore groundwater chemistry was influenced by regional groundwater chemistry. In contrast, at PMSGA, the groundwater flow potential was downward and lake water, influenced by quarry discharge seeping downward into nearshore sediments, produced a different lake and shallow groundwater chemistry than at ESGA. Although the invertebrate and young fish community was similar at the two sites, taxonomic groups tolerant of degraded water quality were more prevalent at PMSGA. Sensitive taxa were more prevalent at ESGA. We propose a conceptual model, based on well-described models of groundwater/ seawater interaction along coastal margins, to describe the interconnection among geologic, hydrologic, chemical, and biological processes in the different nearshore habitats of Lake Erie, and we identify processes that warrant further detailed study in the Great Lakes.

KEYWORDS: Western Lake Erie, groundwater, nearshore, Silurian/Devonian aquifer, water chemistry.

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