An Implicative Study on Carbon Sequestration by Seagrasses at Mandapam, Tamil Nadu

Abstract- The total amount of carbon stored in the sediment of the sea grass bed in Mandapam coast was studied. We analyzed stored carbon in the sea grass plant material and sediment of sea grass at Manadapam coast, Tamil Nadu. Pronounced variation was observed between sediment organic carbon and plant organic carbon with depths in all the 5 sites. The total carbon also exhibited significant variation with core depth in the 5 sites.
Redox potential, pH and organic matter of sediments were also monitored simultaneously to evaluate the stored carbon in the underlying soil of different depths in the study area. In the selected quadrate, the order of abundance of the sea grass species was; Site 5-Halodulepinifolia>Site 2-Cymodocearotundata>Site 3-Cymodocearotundata>Site 4-Halophile decipiens.
The sediment texture of sea grass bed was also analyzed. The accumulation of organic carbon in sea grass plant material was relatively higher than that of sediment. The mean total carbon level in sediment of 5 sites in the Mandapam coast (mg C/ ha) were in increasing order of carbon (Mg C/ha) are; site 2 = 4271.009049 > site 4 =4012.952189> site 5 =4005.007121> site 3 =3443.401944> site 1 = 3275.303809. It was seen that core depths of sediments samples from sites are comparable and shown significant difference from surface to the bottom. The mean carbon level in core depths (cm) of sediment (Mg/C) were in order ; 30 TO 35= 6.1574> 35 TO 40=5.8458 >25 TO 30=5.3401>40 TO 45=4.2456>20 TO 25=3.8446>15 TO 20=3.5837>10 TO 15=2.516>50 TO 100=2.086>45 TO 50=1.5746>5 TO 10=1.4384> 0 TO 5=1.3832. The visual observation from the study area clearly indicates that seagrass bed could have adverse human impacts that cause considerable loss of sea grass.