Grantee Research Project Results
Development of a Bioindicator of Freshwater Influx to Marine Communities Using a Salinity-Sensitive Symbiosis in the Temperate Sea Anemone Anthopleura ElegantissimaEPA Grant Number: U915533
Title: Development of a Bioindicator of Freshwater Influx to Marine Communities Using a Salinity-Sensitive Symbiosis in the Temperate Sea Anemone Anthopleura Elegantissima
Investigators: Cohen, Risa A.
Institution: University of California - Los Angeles
EPA Project Officer: Jones, Brandon
Project Period: September 1, 1999 through September 1, 2002
Project Amount: $77,819
RFA: STAR Graduate Fellowships (1999)
Research Category: Academic Fellowships , Aquatic Ecosystems , Fellowship - Aquatic Ecology and Ecosystems
The objectives of this research project are to: (1) investigate the potential for using the symbiotic sea anemone, Anthopleura elegantissima, as an indicator of salinity stress; (2) understand how changes in environmental conditions affect the relationship between A. elegantissima and its symbiotic zooxanthellae; and (3) develop a bioindicator to measure freshwater influx into coastal subtidal marine communities.Approach:
Three approaches will be used in the development of a temperate bioassay for salinity. First, a number of short-term laboratory experiments will examine the response of A. elegantissima to a range of decreased salinities under various environmental conditions. These experiments are designed to examine the effect of freshwater alone (chronic or pulsed) on A. elegantissima as well as to uncouple the effect of other factors (temperature, light intensity, nutrient concentrations) that interact with salinity in the field. Second, in situ microcosm experiments will test whether the bleaching response in the laboratory is similar to that in the field. Anemones will be exposed to known salinities, but subjected to more natural conditions (e.g., light and temperature). The experimental design will consist of anemones attached to plates with rocklike textures, enclosed in a clear plastic structure, weighted, and attached to the substrate. Water of a known salinity then can be poured into the structure prior to deployment of the experiment, or if the units are filled in the field, a known volume of freshwater can be injected into the experimental unit in situ. Finally, to test the usefulness of A. elegantissima as a bioindicator of freshwater influence in the field, individuals will be positioned in a range of sites with known amounts of freshwater input as well as sites that receive very little freshwater input. For all experiments, the response variables are the number of symbiotic zooxanthellae remaining per mg of animal protein and chlorophyll content.Supplemental Keywords:
fellowship, Anthopleura elegantissima, environmental disturbance, freshwater, zooxanthellae, symbiosis, bioindicator.