双色鹦嘴鱼群排泄沙粒，珊瑚礁的生物侵蚀过程

school of Ember Parrotfish (Scarus rubroviolaceus), aka the redlip or bicolor parrotfish, swimming together above a shallow hard coral reef. These critical marine residents play a major role in reef bioerosion and the production of coral beach sand. While grazing on algae, they ingest and grind swallowed limestone, subsequently excreting fine sand back into the ecosystem. This natural process clears optimal space on the reef for new corals to settle and grow. Shot on a wide-angle lens from a scuba diver POV in the tropical waters of the Andaman Sea, Krabi Province, Thailand.