A geographic information system (GIS) was used to overlay information from a series of databases containing details about habitats, pollution sources, and metal contamination. Using ARC/INFO, a series of maps with various combinations was generated to examine the impact of urbanization and industrialization on the natural resources of Galveston Bay, Texas. The goal was to integrate information from many different sources into a computerized database environment that can be used to represent the impacts associated with this ecosystem. The GIS environment allows for storage and retrieval of data as well as mapping and analytical capabilities. Patterns of spatial distribution can be plotted for different variables, which makes the data easy to visualize when modeling. Resource managers can use this capability to develop comprehensive plans for managing the individual activities within an overall framework. It can be used to identify sensitive areas and to study trends over periods of time. Presented here are a series of maps which represent a preliminary step towards the development of a cartographic model.