Role of sea urchin Lytechinus variegatus Thalassia ... - Inter Research

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found in much of south Florida (Zieman & Zieman. 1989). ... The seagrass habitats of south Florida .... blade then drying and weighing epibionts as described.
Vol. 200: 213-228.2000

MARINE ECOLOGY PROGRESS SERIES Mar Ecol Prog Ser

Published July 14

Role of sea urchin Lytechinus variegatus grazing in regulating subtropical turtlegrass Thalassia testudinum meadows in the Florida Keys (USA) John F. Valentine*,Kenneth L. Heck Jr, Kevin D. Kirsch, David Webb Dauphin Island Sea Lab, 101 Bienville Blvd, Dauphin Island, Alabama 36528-0369, USA and Department of Marine Science,University of South Alabama, Mobile, Alabama 36688-0002, USA

ABSTRACT: In previous work, in St. Joseph Bay, Florida (30"N, 85.5"W), in the northeastern Gulf of Mexico, we found that sea urchin Lytechinus variegatus grazing usually controlled seasonal changes in turtlegrass Thalassia testudinum abundance. In this study, we tested the generality of those conclusions by conducting new grazing studies in 2 turtlegrass habitats in the subtropical Florida Keys (USA).In the first experiment, we varied the duration of sea urchin grazing bouts in order to understand the impacts of temporally varying herbivory on seasonal changes in turtlegrass biomass in shallow water (