Grantee Research Project Results

2001 Progress Report: Biopollution by the Green Mussel, Perna viridis, in the Southeastern United States

EPA Grant Number: R828898
Title: Biopollution by the Green Mussel, Perna viridis, in the Southeastern United States
Investigators: Baker, Shirley M. , Benson, Amy , Phlips, Edward , Williams, James , Nunez, Jose , Baker, Patrick
Institution: University of Florida , United States Geological Survey , Florida Marine Research Institute , Florida Fish and Wildlife Conservation Commission
Current Institution: University of Florida , United States Geological Survey
EPA Project Officer: Packard, Benjamin H
Project Period: June 1, 2001 through May 31, 2004 (Extended to September 30, 2004)
Project Period Covered by this Report: June 1, 2001 through May 31, 2002
Project Amount: $447,602
RFA: Exploratory Research to Anticipate Future Environmental Issues (2000) RFA Text |  Recipients Lists
Research Category: Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration , Water

Objective:

The objectives of this research project are to: (1) assess the potential for the future dispersal of a new biological pollutant, the green mussel Perna viridis, within and from Tampa Bay, FL; (2) assess and predict environmental impacts by green mussels on fouling communities, including artificial substrata, and upon native species at risk of displacement; and (3) assess and predict environmental impacts by green mussels on phytoplankton communities.

Progress Summary:

Field surveys began in October 2001. Green mussel distribution has been qualitatively mapped, and density quantified, within Tampa Bay and as far south as Naples, FL. To date, surveys have not detected this species farther south than Naples, or north of St. Petersburg. Peak densities (>10,000 m^-2, not including small juveniles) have been attained mostly only in Tampa Bay.

Initially, green mussels were largely limited to bridge piers, buoys, and other artificial structures, but more recently, green mussels have been found on high densities on native oyster (Crassostrea virginica) reefs. Where green mussels and oysters coexist, green mussels appear to almost entirely displace oysters. Oyster reefs in Tampa Bay consist mainly of living green mussels and recently dead oysters. However, green mussels remain almost entirely absent from mangroves, a habitat they have invaded heavily on other Caribbean areas. Mangroves, therefore, currently remain an oyster refuge from green mussels in the Tampa Bay. In other natural habitats, green mussels tend to occur in low densities or not at all.

Some field and laboratory data have been collected on green mussel physiological tolerances. Field data from the winter of 2001-2002 infer that green mussels can tolerate near-freezing air temperatures for at least a few hours. No heat-related mortality has been observed in the field, but in the laboratory, thermal limits are about 35 ppt, if temperature is raised too slowly to induce heat-shock proteins. Green mussels are mainly estuarine organisms, and are rare in Tampa Bay at modal salinities below about 17 ppt or above about 29 ppt. The lower limit is most likely physiological, but the upper limit is most likely due to ecological limitations (e.g., predators), rather than physiology.

Baseline data on phytoplankton communities, a prerequisite to feeding studies, is being collected for green mussels. Anecdotal evidence, however, suggests that green mussels are intolerant of blooms of the nuisance red tide dinoflagellate, Karenia (Gymnodynium) brevis. This observation was unexpected, but is sufficiently supported by circumstantial evidence to warrant further examination.

Future Activities:

Work on all components of the project will continue in 2003. We will conduct:

· A major quantitative survey of Tampa Bay habitats in late 2002 or early 2003, to determine the distribution and density of green mussels in various Tampa Bay habitats, across a range of salinities.

· Settlement surveys and histological examination of collected specimens in mid-2003 to determine the reproductive season and cycle of green mussels in Florida.

· Experimental studies of the impacts of green mussels on fouling communities in 2003.

· Lab-based physiological studies will continue in 2003-2004 to examine the roles and interactions of salinity and temperature on limiting green mussel distribution.

· Field studies on plankton communities potentially affected by green mussels will continue, and lab-based feeding selectivity studies will commence in late 2003.

· An expansion of the scope of research to incorporate an ongoing separate study by these researchers on oyster reefs in a nearby estuary. We will compare invaded and non-invaded oyster reefs to estimate impacts by green mussels on this vital ecosystem.

Journal Articles:

No journal articles submitted with this report: View all 13 publications for this project

Supplemental Keywords:

marine, estuary, ecological effects, population, stressor, diet, ecology, surveys, southeast, Florida, FL, ecosystem protection, environmental exposure., RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Geographic Area, Ecological Risk Assessment, State, Ecosystem Protection, Ecosystem/Assessment/Indicators, Southeast, Futures, Monitoring/Modeling, Exp. Research/future, Ecological Effects - Environmental Exposure & Risk, Biochemistry, exploratory research, phytoplankton, FLA, ecological effects, green mussel, marine ecology, biodiversity, Florida, stressors, emerging environmental problems, green mussel infestation, ecological dynamics, ecological pollutants, ecological exposure, biopollution, futures research, conservation

Relevant Websites:

http://fishweb.ifas.ufl.edu/ Exit
http://nas.er.usgs.gov/links.html Exit

Progress and Final Reports:

Original Abstract

2002 Progress Report

2003

Final Report