Recent reports indicate that coral reefs along the Lakshadweep coast in the Arabian Sea and the eastern coast of India along the Bay of Bengal are currently experiencing bleaching. However, experts and government officials note that the situation, while concerning, is not yet at an alarming level and is confined to specific areas.

Coral bleaching is a phenomenon where coral reefs lose their vibrant colours and turn white or pale due to stress-induced expulsion of algae called zooxanthellae, which live in symbiosis with the corals. These algae provide essential nutrients to corals and contribute to their vibrant colours. However, when corals are stressed by factors like high water temperatures, pollution, or changes in water chemistry, they expel the algae, leading to the bleaching effect.

The loss of zooxanthellae deprives corals of their main source of nutrition, making them more vulnerable to disease and death. While corals can recover from short-term bleaching events if conditions improve, prolonged or severe bleaching can result in mass coral die-offs, causing long-term damage to coral reef ecosystems.

In India, coral reefs are predominantly found in various regions such as Lakshadweep, the Gulf of Kutch, Goa, Maharashtra, the Gulf of Mannar, Kerala, and Tamil Nadu. As of now, widespread bleaching has been observed only in the Lakshadweep islands, particularly in three locations within Kavaratti island and its neighbouring atolls.

According to Wenzel Pinto, a research assistant at the Oceans and Coasts Programme Nature Conservation Foundation, the current bleaching event is more extensive compared to the one experienced during 2015-16. Pinto notes that the bleaching is affecting a wide range of coral species, including typically stress-tolerant ones like Porites lutea and Pavona varians.

Differences in bleaching severity have also been observed among different islands, with reports indicating less severe bleaching in areas like Agatti compared to Kavaratti. Furthermore, the impacts of bleaching extend beyond hard corals to include soft coral species, giant clams, and sea anemones.

In Goa, coral bleaching has begun, but is currently limited to the Goniopora species. Venkatesh Charloo, founder trustee of Coastal Impact, mentioned that bleaching in Goan coral reefs is an annual occurrence, typically starting in early May. However, this year, bleaching was reported earlier, in late April.

Meanwhile, in the Andamans, coral bleaching has expanded from Havelock Island to areas near Wandoor in South Andaman. Tanmay Wagh from Dakshin Foundation highlights the high risk of further bleaching if temperatures remain elevated.

Similarly, reports from Tamil Nadu indicate patchy coral bleaching, although the situation is not deemed alarming due to recent rainfall lowering sea temperatures. Srinivas Reddy from the forest department mentioned that recovery is possible if temperatures stabilise.

The ongoing bleaching event, declared the fourth global mass coral bleaching event, poses a significant threat to marine life. Coral reefs are vital ecosystems, often referred to as 'rainforests of the sea', providing essential food and habitat for numerous species.

The current El Nino event, contributing to increased sea surface temperatures, is a primary factor exacerbating coral bleaching. Although some areas like Mithapur (adjacent to the Gulf of Kutch) have not shown signs of bleaching yet, continuous monitoring is crucial.

The disruption of the symbiosis between corals and zooxanthellae due to high water temperatures leads to bleaching. While corals can recover from bleaching, prolonged episodes can result in mass mortality, hindering their ability to regenerate.

Historically, global mass coral bleaching events have been recorded in 1998, 2010, 2014, and 2017, with significant impacts seen, such as in Australia where over 50% of reefs were affected during 2016-17.

The current situation underscores the urgent need for conservation efforts and climate action to protect these vital marine ecosystems from further damage.