Depth Distribution of Thalassia testudinum in two Meadows on the West Coast of Florida; a Difference in Effect of Light Availability

Abstract. Shoot density was lower, while leaf area index and above- to below-ground biomass ratios were higher for Thalassia testudinum collected from the deep edge when compared to the shallow edge of a meadow off Anclotc Key, Florida. These three characters followed patterns predicted from previous studies. The characters were reversed in order for plants from shallow and deep edges of a meadow off Egmont Key, about 50 km south of Anclote Key. Causes other than light were not evident to explain this reversal in the Egmont Key meadow. This study suggests that although light limitation may be the usual limiting factor for depth distribution in seagrass meadows, other factors cannot be ignored in many meadows along the west coast of Florida.