Oxybenzone is one of the most common chemical UV filters found in sunscreens. When it enters the ocean, it causes devastating harm to coral reefs at extremely low concentrations (as low as 62 parts per trillion). It triggers viral infections in coral symbionts (zooxanthellae), leading to coral bleaching as the coral expels its life-sustaining algae. Oxybenzone also causes DNA damage in coral larvae, deforms their skeletons, and prevents proper settlement and metamorphosis. Studies show it acts as an endocrine disruptor across multiple marine species, affecting reproduction and development in fish, sea urchins, and other reef organisms.