A resilient reef's structure
The Kalpitiya Bar Reef Marine Protected Area is the largest and most biodiverse coral reef system in Sri Lanka, covering 306.7 square kilometers. It was declared a marine sanctuary in 1992. The sanctuary contains a complex of reefs, including shallow coral gardens and deeper sandstone ridges. This sandstone substrate is an important feature; unlike typical limestone reefs built by coral skeletons, these reefs are based on sedimentary rock, providing a different foundation for coral settlement.
The reef hosts at least 156 species of coral and 283 species of fish. Common fish include parrotfish, angelfish, and butterflyfish. The ecosystem also supports larger marine life like manta rays, blacktip reef sharks, and sea turtles. The dominant coral genera responsible for much of the reef's structure include Acropora, Montipora, Echinopora, and Pocillopora.
Catastrophe and comeback
In 1998, a severe bleaching event caused by elevated sea surface temperatures reduced the live coral cover on Bar Reef to less than 1%. The reef showed remarkable resilience, recovering significantly within a decade. However, disaster struck again with the 2016 El Niño event. This warming episode was catastrophic, reducing live coral cover to less than 1% in some areas and, in one survey, killing more than 92% of the corals.
Following the 2016 bleaching, a concerted conservation effort began. In 2018, stakeholders established a "No-Go Zone" marked by buoys to protect core areas from fishing and other human disturbances, allowing natural recovery to proceed. Scientists and community members began monitoring the reef, observing the settlement of new coral recruits. New coral polyps, though small, were seen attaching to the rubble and to artificial concrete structures placed on the seabed to aid recovery. This rapid response and the reef's natural resilience factors are subjects of ongoing study, providing data on how some reef systems can rebound from near-total collapse.