Research Product

Northern Gulf of Mexico Thalassia testudinum biomass, leaf measurements, and shoot growth rates were determined during three surveys each from a different meadow over consecutive years, and correlated with sediment biogeochemical measurements by correlation analyses and multiple stepwise regression analyses. ANOVA indicated significant differences in amounts of above- and belowground biomass between surveys, and between stations at deep stations in comparison to shallower stations. Shorter and narrower leaf lengths and widths during the last two surveys may have been related to low salinity stress and light limitation following heavy seasonal rains. The stress from low salinity and light limitation might contribute to the slow ongoing loss of seagrass from Santa Rosa Sound. Sediment biogeochemical measurements indicated the importance of iron and suggested presence of microbial iron reduction. Correlation analyses showed that leaf phosphorus content was related to sediment concentrations of iron and phosphorus and inversely related to total reduced sulfur. The results further illustrate relationships among water quality, sediment biogeochemistry and seagrasses