THE CARBON SEQUESTRATION BY PHYTOPLANKTON IN TROPICAL LAKE AND RESERVOIR

The increasing of atmospheric carbon dioxide has become a public and scientific concern, especially in potential aquatic ecosystem such as lake and reservoir as carbon sequestration is inevitable to decelerate the global warming process. The aim of the study is to estimate carbon sequestration by phytoplankton in tropical lake and reservoir, case study in Maninjau Lake (0 degrees 19'S; 100 degrees 12'E), West Sumatera Province and Pluit Reservoir (6 degrees 6'58.13 '' S; 106 degrees 47'54.69 '' E), Jakarta Province, Indonesia. The study was conducted in eleven sampling points to represent the lake during in May-July 2016 in Pluit Resevoir and in May-July 2017 in Maninjau Lake. Plankton nets were used for sampling phytoplankton. The determination of sampling points are based on the Indonesian National Standard 6989.57: 2008 regarding the method of sampling of surface water. Phytoplankton sampling was carried out by filtering water samples as much as 100 liters from 50 cm surface water by using a plankton net (25 mu m mesh size). To find out the ammount of carbon sequestration an analysis was carried out to measure the abundance of phytoplankton communities and the concentration of chlorophyll-a. The results of this study revealed the abundance of phytoplankton in Maninjau Lake range 78-273-cell/l belonging to 4 classes and carbon sequestration average was 0.0504 mgC/m(3). However, in Pluit Reservoir abundance range was 72-800 cell/l belonging to 2 classes with carbon sequestration average 0.1181 mgC/m(3). The study concluded that phytoplankton could give the information about the carbon sequestration rate and as instrumental in formulating efficient strategies related to carbon sequestration.