Sun-seekers off the coast of Zhanjiang City in south China's Guangdong Province were treated to a rare sight – pink Indo-Pacific humpback dolphins breaching the waves.

Dubbed the "giant pandas of the sea," these dolphins aren't born pink. They only get that rosy hue as adults as blood vessels near the surface of their skin expand to keep them cool.

But their return is turning heads for a bigger reason. The dolphins are notoriously sensitive to water quality, proving local anti-pollution efforts are paying off.