Spatial Variability In Distribution Of Seagrasses Along The Tamilnadu Coast

Seagrasses are one of the predominant groups of marine flora that grows in tidal and subtidal region of the shallow coastal environment. Spatial variability of seagrass distribution, biomass, canopy height, productivity and environmental parameters were recorded at 24 stations all along the Tamilnadu coast during 2011 and 2012. Thirteen seagrass species of six genera were recorded, among which H. ovalis was found to be distributed all along the coast of Tamilnadu, and C. serrulata was found densely populated in the shallow coastal regions of Palk Bay and Gulf of Mannar (GOM). H. beccarii is the rare species found only in Vellar estuary of Parangipettai. Biomass (36.2 gfr.wt.m-2 - 1218 gfr.wt.m-2), productivity (0.01 g C m-2 d-1 - 4.34 g C m-2 d-1) and canopy height (0.28cm -107.73 cm) of seagrass species varied among all species of seagrasses. Correlation coefficient indicate that the local environmental parameters, particularly inorganic phosphate and total phosphorus are two important nutrients and sediment texture play a prominent role in influencing seagrass biomass, productivity and canopy height by enhancing the growth of seagrasses. Hence the present study suggests continuous monitoring of ecological and biological variables in time and space is highly required for managing the resources efficiently.