Is the whirlpool of Feng Dan fish a one-off thing?

Fontaine fish won't last forever. Fontainebleau is a migratory fish that migrates from ocean or river to freshwater lake or river to breed and lay eggs in a specific season. During spawning, fish will gather together. Once the reproduction is completed, the fish will disband and return to the sea or other parts of the freshwater lake to continue their lives.