When a whale dies it usually sinks to the bottom. This is called whale-fall.
The corpse will then nurture a diverse range of organisms, of a period of many years. They follow a succession - like trees and shrubs in a forest growing up in a cleared area once it is left alone - and form a unique ecosystem. A range of organisms are specialised to live only in these whale-falls.
That is quite surprising - to me anyway - but even more so is that fossil deposits have been found that looks like plesiosaur-falls: giant marine reptiles from long before whales existed died and sank and their carcasses supported communities much like those of present day whale-fall ecosystems.