Edited version published in the Andaman Chronicle.
A famous Disney animation movie introduced the underwater world through a movie, Finding Nemo. The movie was well received and Nemo, the clown fish, received a lot of attention, not only with children but also with grown ups .
The habitat of Nemo is coral reef ecosystem, which is a colony of individual corals. The coral animal or polyp has a simple gut that opens at one end and a mouth surrounded by tentacles. These tentacles live in association with algae called zooxanthallae. They form a calcium carbonate structure, which is the main skeleton of the reefs. Corals thrive in bright, sunlit, nutrient-rich areas and provide habitat for thousands of organisms including fish and a variety of other marine life—from large mammals to tiny shells.
However over the recent years this ecosystem has been threatened due to destructive fishing practices, pollution and their sensitivity to global climate change. In Andaman and Nicobar islands, the reefs have a history of suffering. In 2004 there was a massive tsunami, which impacted the reefs. At some sites, coral reefs were broken into chunks while in others, suffocated by piles of mud and debris. Just when reefs had begun to recover, they were affected by yet another natural disaster—the bleaching of 2010.
The bleaching or whitening of corals occurs when there is sudden increase in sea-surface temperature. Coral animals are sensitive to temperature changes and require warm water between 25-27° C to thrive. When temperature increases, there is a breakdown of the symbiotic relationship between corals and algae resulting in death of the reefs.
Certain areas got heavily affected whereas other survived the bleaching. Why a few areas survived, while others got affected is interesting; and understanding the processes and mechanism of bleaching could help managers to concentrate their efforts on areas that are naturally resilient to bleaching.
Currently, Andaman Nicobar Islands’ Environmental Team (ANET) is conducting in-depth research to unravel the mystery of why a few reefs survived this bleaching event while the others didn’t. By conducting a series of reef surveys and comparing the various levels of destruction and resilience, we will be able to get a glimpse into this complex event. This will allow us to understand Nemo’s habitat – the coral reef system better so that we can begin taking steps to protect it. While this may not directly result in reversing the effects caused by the bleaching, it can certainly lead to better resource planning and management such as, reducing the man made impacts like habitat destruction, pollution, overfishing and improper disposal of garbage, giving hope to the future of the reefs.