Master's Thesis Abstract

THE EFFECTS OF ENVIRONMENTAL STRESS AND PRIMARY PRODUCTIVITY ON FOOD CHAIN LENGTH IN FLORIDA BAY

by

Patricia Lyn Mumford

Florida International University, 1999

Miami, Florida

Professor James W. Fourqurean, Major Professor

 

The aim of this investigation was to determine if stress (i.e. salinity variability) or seagrass primary productivity played an important role in structuring epibenthic food chain length found within Florida Bay. Not much is known concerning the trophic interactions among species that utilize the seagrass beds in Florida Bay, nor what consequences seagrass primary productivity and salinity have had in influencing these trophic relationships. Nitrogen stable isotopes were used as an indicator of food chain length across sites. No significant differences in food chain length were found across stress levels, productivity levels, or across productivity levels within each basin. There were however, significantly longer food chain lengths found within the high stress basins once Whipray Basin was excluded. As management policies are changed, affecting Florida Bay, baselines need to be established to understand what effect these actions will have on seagrass communities.