Coral reefs are among the most threatened ecosystems on Earth, primarily due to the rapid warming of the oceans. Even small but prolonged increases in temperature can trigger marine heatwaves, leading to widespread coral bleaching.
Ocean acidification further weakens the calcium carbonate skeletons of reef‑building corals. As seawater becomes more acidic, less carbonate is available for skeletal formation. Corals grow slower, their skeletons become thinner and more fragile which makes them more vulnerable to storm damage and erosion.
On a local scale, reefs are harmed by pollution and physical destruction: coastal development, dredging, sediment runoff, and nutrient pollution from agriculture and wastewater reduce water clarity and promote algal blooms that can overgrow corals.
Overfishing, as well as destructive fishing methods such as blast fishing and cyanide fishing, remove key species and directly damage the reef’s three‑dimensional structure. Diseases also spread more easily in stressed reefs and, combined with bleaching, can drastically reduce entire colonies or species.
