Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you have safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
Contact Us

Grantee Research Project Results

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

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 9 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

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

Progress and Final Reports:

  • 1997
  • 1998
  • Final Report
  • Top of Page

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

    Project Research Results

    • Final Report
    • 1998
    • 1997
    9 publications for this project
    3 journal articles for this project

    Site Navigation

    • Grantee Research Project Results Home
    • Grantee Research Project Results Basic Search
    • Grantee Research Project Results Advanced Search
    • Grantee Research Project Results Fielded Search
    • Publication search
    • EPA Regional Search

    Related Information

    • Search Help
    • About our data collection
    • Research Grants
    • P3: Student Design Competition
    • Research Fellowships
    • Small Business Innovation Research (SBIR)
    Contact Us to ask a question, provide feedback, or report a problem.
    Last updated April 28, 2023
    United States Environmental Protection Agency

    Discover.

    • Accessibility
    • Budget & Performance
    • Contracting
    • EPA www Web Snapshot
    • Grants
    • No FEAR Act Data
    • Plain Writing
    • Privacy
    • Privacy and Security Notice

    Connect.

    • Data.gov
    • Inspector General
    • Jobs
    • Newsroom
    • Open Government
    • Regulations.gov
    • Subscribe
    • USA.gov
    • White House

    Ask.

    • Contact EPA
    • EPA Disclaimers
    • Hotlines
    • FOIA Requests
    • Frequent Questions

    Follow.