system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do the carcasses of marine animals, particularly large ones like whales, not spread diseases throughout the ocean?
gpt
The same reason the carcasses of land animals don't spread diseases: it's difficult to spread diseases when you don't move around, and they're eaten before they have a chance to do much moving around. 

Apart from this, diseases that thrive in warmblooded air breathers rarely do particularly well in cold blooded water breathers. The environments are simply too different.