Multiscale Assessment of the Population Status of Thalassia testudinum A New Approach to Ecosystem Assessment

EPA Grant Number: R825145
Title: Multiscale Assessment of the Population Status of Thalassia testudinum A New Approach to Ecosystem Assessment
Investigators: Carlson, Paul R. , Durako, Michael J. , Fourqurean, James W. , Landsberg, Jan H. , McRae, Gil , Moncreiff, Cynthia A.
Current Investigators: Carlson, Paul R. , Durako, Michael J. , Fourqurean, James W. , Madley, Kevin , McRae, Gil , Merello, Manuel , Moncreiff, Cynthia A. , Randall, Todd , Rose, Craig D. , Yarbro, Laura A.
Institution: Florida Marine Research Institute , Florida Department of Environmental Protection , Florida International University , University of Southern Mississippi
Current Institution: Florida Marine Research Institute , Florida International University , Oregon State University , University of Southern Mississippi
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1996 through September 30, 1999
Project Amount: $758,386
RFA: Ecological Assessment (1996) RFA Text |  Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Ecosystems

Description:

The purpose of this project is to examine spatial-scale dependence (seagrass patch-to-regional) and sample size effects on the variation of a number of well-established indicators of ecological condition for the dominant seagrass in the Gulf of Mexico. This study will also test the application of several new, potentially more robust, indicators of ecological condition. In order for an organism or biological parameter to be useful as an indicator of estuarine condition or health, sources of variation must be partitioned between those that reflect natural cycles or gradients (i.e., seasonal or latitudinal variation), and those that are associated with both natural (e.g., tropical storms) and anthropogenic (e.g., point and nonpoint source sewage effluent, non-point source runoff, industrial effluents, etc.) stress or disturbance. The proposed research design will examine scale-based and stress/disturbance-based variability and will apply a statistical evaluation of appropriate sampling designs for ecosystem assessment. This will be accomplished using a hierarchical sampling design based on tesselated hexagons at multiple scales (e.g., 100s, 10,000s, and 1,000,000s m2) at locations representing relatively pristine conditions and a range of natural and human-related disturbance regimes, thus providing an extensive regional coverage (northern and eastern Gulf of Mexico). The specific objectives of the proposed research are to: 1) evaluate the effect of spatial scale (i.e., patch, meadow, basin, region, latitude) on the variability associated with estimates of shoot-based and population-level characteristics of apparently healthy Thalassia testudinum populations and populations under the influence of natural and human-related disturbance and stress regimes; and 2) evaluate the efficacy of recently-developed reconstructive aging techniques, in concert with visual-assessment, structural (e.g., cover, abundance, shoot density, leaf numbers and lengths, leaf widths, leaf area index, etc.), disease, biochemical (stored reserves), elemental (leaf C:N:P) and stable isotopic (_13C, _15N, and _35S) analyses, in determining the most effective protocol for assessing the ecological condition of Thalassia testudinum populations and their adjacent ecosystems.

Publications and Presentations:

Publications have been submitted on this project: View all 4 publications for this project

Supplemental Keywords:

ecosystem, indicators, scaling, ecology, Gulf of Mexico, RFA, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, exploratory research environmental biology, Ecosystem/Assessment/Indicators, Chemical Mixtures - Environmental Exposure & Risk, Ecosystem Protection, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Gulf of Mexico, Ecological Indicators, risk assessment, aquatic, multi-scale biophysical models, Thalassia testudimum, ecosystem assessment, stressors, multiple spatial scales, Seston C:N:P ratio, disturbance based variable, estuarine ecosystems, aquatic ecosystems, assessment methods, population-based, spatial and temporal patterns, disease

Progress and Final Reports:

  • 1997
  • 1998
  • Final Report