PARENT SESSION
Symposium 20: Defining and Applying Environmental Indicators in Coastal Ecosystems
Organized by: R Howe and G Niemi
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Chatham Ballroom B.

Modeling ecological condition in upstream watersheds and downstream estuaries in the Atlantic Slope region.

Wardrop, Denice^*,1, Brooks, Robert¹, Myers, Wayne¹, Patil, G.¹, Taillie, Charles¹, ¹ Penn State University, University Park, PA, USA

ABSTRACT- The Atlantic Slope Consortium (ASC) is a project designed to develop and test a set of indicators in coastal systems that are ecologically appropriate, economically reasonable, and relevant to society. It extends the area relevant to coastal condition into freshwater aquatic ecosystems in the headwater regions of the Appalachian Mountains, and the project area covers the Delaware, Chesapeake, and Albemarle-Pamlico drainage basins. The project utilizes ecological and socioeconomic information compiled at the scale of estuarine segments and small watersheds. The research mandate of the ASC project is the following: Using a universe of watersheds and estuarine segments, covering a range of social choices, we ask two questions: * How "good" can the environment be, given those social choices? * What is the intellectual model of condition within those choices, i.e., what are the causes of condition and what are the steps for improvement? As a basis for compiling ecological indicators, a watershed/estuarine segment classification system was developed representing the range of social choices. These watershed/estuarine segment classes were the basis for an analysis of the explanatory power of various indicators through the following steps: 1. Identification of critical areas of low biological integrity on the watersheds across the project area. This was accomplished by use of the scan statistic originally developed for geographical surveillance of disease, and adapted to regional environmental and ecological settings. 2. Reassessment of critical areas taking into account potential explanatory factors. Three categories of factors (or indicators) were evaluated: descriptive (e.g., land use and landscape), structural (e.g., drainage pattern, geomorphology), and network-related. 3. Modeling of those critical areas which were not satisfactorily accounted for in the preceding step by general landscape and drainage variables This exercise provides an initial screening of ecological indicators with regard to their explanatory power at various spatial scales, utilizing steps 1 and 2 above. The utility of various indicators for each of the watershed/estuarine segment categories is reported.

Key words: Mid-Atlantic, critical areas, ecological indicators, watersheds