The general goal of this study was to provide the first quantitative analysis of habitat changes in the Lake Erie ecosystem which are associated with the expansion of Dreissena assemblages on soft-substrates. The general objectives of this study were to: (a) Determine the coverage of Dreissena assemblages on different soft-substrate types in Lake Erie. (b) Characterize the Dreissena assemblages (size frequency, density and species composition) on different soft-substrate types in Lake Erie. (c) Assess the expansion of Dreissena assemblages on different soft-substrate types in Lake Erie. (d) Predict the overall soft-substrate distributions and abundances of Dreissena assemblages in Lake Erie. To accomplish these objectives, this study integrated Side Scan Sonar, Remotely Operated Vehicle and SCUBA surveys of soft-substrate Dreissena assemblages in the context of existing sediment charts and bathymetric data for Lake Erie. Based on these data sets, a paper published in Nature by Paul Berkman and his colleagues and a masters thesis was completed by Melissa Haltuch. Melissa Haltuch and Paul Berkman also obtained the copyright for a "Lake Erie Geographic Information System" CD-ROM that would become available to the public. Specific objectives of this development fund grant are to: (1) Publish an initial 100 copies of the "Lake Erie Geographic Information System" CD-ROM for public dissemination, starting with the International Association for Great Lakes Research (IAGLR) symposium. (2) Publish an article in Limnology and Oceanography that includes a color overlay of the bathymetric and substrate layers by Melissa Haltuch as part of her masters thesis.

Public availability of the "Lake Erie Geographic Information System" CD-ROM is essential for on-going modeling efforts to understand ecosystem changes associated with one of the most productive freshwater fisheries in North America. This CD-ROM will provide the first basic GIS framework (bathymetry and substrates along with estimated Dreissena distributions) that is necessary for adding the appropriate information layers which are of interest to scientist and resource managers in Lake Erie. In addition, this CD-ROM will be of provide an educational tool for individuals involved with college and pre-college curricula, recreation, industry and other activities which are important to the State of Ohio and the Sea Grant College program. The initial dissemination of the CD-ROM at the IAGLR meeting will provide an opportunity to share this innovation broadly with the above user communities.

The publication of the article in Limnology and Oceanography (Haltuch, M.A. and Berkman, P.A. 1999) will disseminate information about the relationships between bathymetry and substrates in Lake Erie. Modeling expansion of exotic mussels on Lake Erie sediments using Geographic Information Systems (GIS) with color image will provide the first integrated GIS assessment of the lakewide relationships between bathymetry, substrates and Dreissena associated with the Lake Erie ecosystem. The color image is the only format (as opposed to a black-and-white line drawing which lacks information) for conveying the multi-dimensional relationships between bathymetry and substrates in Lake Erie.

The methods behind the creation of the "Lake Erie Geographic Information System" CD-ROM and Limnology and Oceanography publication are described in:

Haltuch, M.A. 1998. Modeling expansion of exotic mussels on Lake Erie sediments using Geographic Information System (GIS). Masters Thesis, The Ohio State University, Columbus. pp. 104.

The Lake Erie Geographic Information System CD-ROMs were produced and distributed; a journal article was published.