Ducks, cranes and other aquatic birds abound in the delta.
Tadpoles are aquatic vertebrates.
The Amphizoidae, for example, a small family of aquatic beetles, are known only from western North America and Eastern Tibet, while an allied family, the Pelobiidae, inhabit the British Isles, the Mediterranean region, Tibet and Australia.
Numberless aquatic birds visit it for breeding purposes.
At Beaufort the United States Bureau of Fisheries has a marine biological laboratory, established in 1901 for the study of the aquatic fauna of the south-east coast.