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

Evaluation of significant sources influencing the variation of physico-chemical parameters in Port Blair Bay, South Andaman, India by using multivariate statistics

Port Blair is the capital city of Andaman & Nicobar Islands, the union territory of India. More than 50 of the population of these islands lives around Port Blair Bay. Therefore the anthropogenic effects in the bay water were studied for monitoring purpose from seven stations. Physico-chemical parameters of seawater were analyzed in samples collected once in every 3. months for 2. years from seven sampling stations located in Port Blair Bay, South Andaman Island to evaluate the spatial and tidal variation. Cluster analysis and factor analysis were applied to the experimental data in an attempt to understand the sources of variation of physico-chemical parameters. In cluster analysis, the stations Junglighat Bay and Phoenix Bay having high anthropogenic influence formed a separate group. The factors obtained from factor analysis indicated that the parameters responsible for physico-chemical variations are mainly related to land run-off, sewage outfall and tidal flow