Sandbar Lecture Series: What is Happening to Earth’s Coral Reefs?

Tropical reefs across the globe have suffered unprecedented losses of coral cover, with those in the Indo-Pacific following the same trajectory as the Caribbean. UNCW’s Dr. Joseph Pawlik askes : What will be the fate of former coral reef ecosystems decades from now? If the Caribbean is any guide, future reefs will be dominated by seaweeds, gorgonians, and sponges. Recent estimates of sponge pumping activities combined with discoveries related to carbon and nutrient cycling have revealed a feedback loop: seaweeds release dissolved organic matter (DOM) which is consumed by some sponges as a major portion of their diet, while sponges release inorganic nutrients that further enhance seaweed growth. Seaweeds and sponges will likely outcompete other benthos, including remaining corals. As limestone reefs degrade, sponges may be the only structural complexity for fishes and invertebrates. Reef fish and vertebrate communities will shift to reflect the available benthos, with increases in… View Source