Center for Coastal Resources Management

Research: Nearshore Habitats and Coastal Stressors

Estuarine & Great Lakes (EaGLe) Coastal Initiative- Atlantic Slope Consortium (ASC)

ASC was one of 5 estuarine indicator programs under the EaGLe initiative http://www.asc.psu.edu/
Funding was through the US Environmental Protection Agency’s (US EPA) Estuarine and Great Lakes Program (http://www.es.epa.gov/ncer/centers/eagles/). Universities within the Consortium: Virginia Institute of Marine Science (VIMS), Smithsonian Environmental Research Center (SERC), Penn State University.

 ASC Overall Goal: To develop a suite of ecological and socioeconomic indicators for assessing and managing the condition of the vital resources in the Mid-Atlantic region

The effects of land use patterns on nearshore estuarine ecosystems

Estuarine segments selected to study were based in part on primary land use which ranges from forested to highly agricultural or developed (left map = SERC study segments; right map = VIMS study segments)

List of potential environmental indicators of the health of the Bay examined by the ASC.

Examples of linkages between patterns of land use and environmental indicators in estuarine habitat

A) Objective: to examine the influence of subtidal habitat, shoreline alteration and watershed land use on nearshore fish communities in the Chesapeake Bay.

Nearshore Fish Community Responses to Habitat Condition in the Subtidal on the Shoreline and throughout the Watershed

A fish community index (FCI) was developed as a relative measure of fish community structure and function in nearshore, estuarine systems.  The index consists of metrics that represent key aspects of fish community integrity, as well as the elements of life history that are dependent on estuarine condition. Metrics reside in four broad categories: taxonomic richness and diversity, abundance, trophic composition, and nursery function.  We then examined relationships among nekton community measures (FCI) and habitat measures (shoreline modification, developed lands, and subtidal habitat).

Links
Bilkovic, D.M., C.H. Hershner, M.R. Berman, K.J. Havens and D.M. Stanhope. December 2004. Evaluating Nearshore Communities as Indicators of Ecosystem Health. Estuarine Indicators Workshop Proceedings, In: Estuarine Indicators, Stephen Bortone, ed., CRC Press, Inc., Vol. 28, 365-379. More info

B) Objective: to examine the influence of shoreline alteration and watershed land use on nearshore macrobenthic communities using established indices for related estuarine environments.

Tipping points/thresholds:Ecological thresholds mark breakpoints at which a system or community notably responds (perhaps irreversibly) to a disturbance.

We measured the effect of developed land use on nearshore macrobenthic communities. Macrobenthic index scores decreased with anthropogenic alterations to the landscape (e.g. developed watersheds), and thresholds were identified for riparian and watershed developed land use (10-12 %) beyond which a response in macrobenthic communities is reflected in consistently low scores with reduced variability, which is indicative of stressed conditions.

Negative macrobenthic community responses occurred when developed shorelines were 10% or higher.

Links: D.M. Bilkovic, M. Roggero, C.H. Hershner, and K. Havens. 2006. Evaluating Benthic Indices for use in nearshore estuarine habitats. Estuaries and Coasts 29(6B): 1185-1195. Link

C) Tipping points for a variety of ecological indicators in the Chesapeake Bay in relation to the amount of Developed lands

 Bilkovic, D.M., other ASC researchers.  Coastal development impacts on biological communities in the Chesapeake Bay- Examples from the Atlantic Slope Consortium. December 2006. Living Shorelines Summit. Bringing together diverse perspectives to address shoreline protection alternatives, Williamsburg, Virginia. Keynote speaker.  (Coastal development impacts on biological communities in the Chesapeake Bay: Examples from the Atlantic Slope Consortium)

FINAL ASC REPORT

ASC Brochure link-- “A manager’s guide to indicator selection”, published by EPA. 2006.

Summary

• Both the amount of development and its proximity to the estuary or wetland contributes to degradation of aquatic resources.

• In general, > 20% development (at local and/or watershed levels) was related  to shifts in biological communities (indicators), revealing possible ecological thresholds

• Forest buffers were also noted to reduce sediment and nutrient loads along stream corridors or around wetlands

• In many instances, local development had stronger links with the  aquatic resource than watershed development

Additional Products from ASC

Developing and Communicating a Taxonomy of Ecological Indicators: A Case Study from the Mid-Atlantic EcoHealth 4, 179–186, 2007. Denice Heller Wardrop, Carl Hershner, Kirk Havens, Kent Thornton, & Donna Marie Bilkovic

The Atlantic Slope Consortium (ASC) developed a taxonomy of ecological indicators to facilitate the application and evaluation of indicator selection and use, as well as the integration of appropriate indicators into environmental decision-making.  The framework was based upon three primary elements: 1) The specific questions to be answered (the type of indicator), 2) The spatial and/or temporal scale of the issue being addressed (the spatial/temporal scale over which the indicator is valid), and 3) The context of the question, using categories of surrounding land use as surrogates for social choices. A Fish Community Index (FCI) developed for the ASC will provide an example of utilizing the framework to select an indicator, as well as using the framework to judge the utility of the indicator. http://www.springerlink.com/content/k856nq840331w401/fulltext.pdf

Assessment of Chesapeake Bay Program Selection and Use of Indicators EcoHealth 4, 187–193, 2007. Carl Hershner, Kirk Havens, Donna Marie Bilkovic, and Denice Wardrop

The utility of a taxonomy of ecological indicators developed by The Atlantic Slope Consortium (ASC) was evaluated through application within the Chesapeake Bay Program. We considered a set of 82 metrics generated by this Program, using qualitative assessment of descriptive materials. We found that 30 of these metrics conveyed sufficient information about the larger system to be considered true indicators. These 30 were classified according to the proposed taxonomy into one or more of five types: condition, evaluation, diagnostic, communication, or futures. We also evaluated the scales at which these indicators function temporally and spatially. We conclude that only a limited number of indicators are designed to be diagnostic and/or designed to forecast future conditions. The scale analyses suggest the indicator set is not focused on local scales and/or the watershed component of the Bay system. The taxonomy succeeds in framing an assessment of existing indicator sets that can productively guide future development efforts. http://www.springerlink.com/content/d700vn2j517t4662/fulltext.pdf