Abstract

Grain size and content analyses was made of the top 3 in. of sediment from 33 cores taken across 3 species-specific seagrass beds in Estero Bay Aquatic Preserve, southwestern Florida during 1999. The seagrass beds contained some algae with abundant Thalassia, Halodule, and Thalassia-Halodule mix, while the sediment was largely composed of varying amounts of quartz sand, silt-sized quartz, and carbonate skeletal particles. Comparison of sediment from different species of seagrass reveals a difference in terms of pan size characteristics. There is a significantly higher content of silt in Thalassia and Thalassia-Halodule mix sediments than in Halodule beds. This species-specific preference difference may not be due to wave-energy and sediment-size alone, but may also be due to freshwater runoff influence. Sediment-trap collections during summer and fall of 1999 and 2000, the wet and dry seasons in southern Florida, give a particle flux ranging from 10 to over 100 g/diem that increased during periods of high winds, due to the very shallow nature of the bay (<3 ft). During the dry season of 1999/2000 the flux range was lower. It is not known how much of this flux has come from local resuspension of sediment particles or direct imput from the Gulf of Mexico.