Status of the benthos and its environment in Jolly Buoy Island, Mahatma Gandhi Marine National Park, Port Blair, Andaman and Nicobar Islands

Abstract

The present work has been carried out in Jolly Buoy Island of Mahatma Gandhi Marine National Park, Andaman and Nicobar Islands to understand benthic distribution and environmental factors. Four random belt transect were laid around Jolly Buoy island to study the biotic and abiotic components. The following hydrographic parameters were collected and monitored in every month, viz, temperature, salinity, water depth, pH, Eh, dissolved oxygen, turbidity, nitrite, nitrate, inorganic phosphate, and silicate. On the tidal and nearshore environment, 1 m quadrate was laid along the belt transect to collect the sediment samples to study the meiofaunal assemblages. The substratum of the four transects of the Jolly Buoy reveals that sand is predominant in their area (45-90%). Hard corals (10%) and nutrient indicator algae (2-19%) were present. The present study exhibited that the coral growth was noticed 35 m from the shore onward, and this was because of the effect of the tsunami in 2004. The diversity of macrofaunal community structure was highest in the transect 1 compared with other transects. The hydrographical study of these transects suggested that the temperature, dissolved oxygen, pH, and salinity variations occurred mainly due to the local environmental influences. Similarly, the nutrients nitrite (NO 2), nitrate (NO 3), inorganic phosphate (IP), and silica variations were mainly due to the land-based runoff influences. The study suggests that the deteriorations of the corals are not due to the climatic change but due to the increase of nutrients in the environment. It is concluded that the environment has vibrant and active for the growth of the benthic community.