Environmental quality assessment of Treis Island, Nicobar, India

The physico-chemical, biological and microbiological parameters of surface seawater was studied at Tries Island during a survey in 2009. The physico-chemical parameters like silicate and inorganic phosphate concentration varied significantly from 3.53 to 4.22 and 0.05 to 0.09 μmol/L, respectively at Tries Island. The zooplankton population density ranged from 4696 to 8207 Nos./m³ and the dominant group was Copepod. The zooplankton biomass also varied significantly from 0.31 to 0.72 ml/m³. The phytoplankton density and species number also varied significantly from 1020 to 1220 Nos. /L and 25 to 31 numbers, respectively. Soleniae dominated in coastal waters of Treis Island. Chlorophyll-a, and phaeophytin concentration varied between 0.12 to 0.24 and 0.06 to 0.27 mg/m³, respectively. The chlorophyll-a concentration variation was significant. Apart from that noise level, soil and plant diversity were also investigated. Soil parameters indicated its fertile nature which is being utilized for horticulture by tribal community living in the neighbouring islands. The present study gives an account of the existing environmental quality in and around the island, providing a baseline scenario to assess the environmental impacts due to developments in the future. This study also provides comparison between populated and unpopulated coastal bay/marine ecosystems.