If I’m thinking of some symbiosis, the sound, sight and shadow of the boats probably scares the fish out of hiding/camouflage, which makes them easier for the cormorants to catch. And then humans figured out how to train the cormorants following the boats and gobbling up all the fish.
They hang out there during migration.
Some Chinese fisherman have trained them to fish for them which is pretty wild: https://www.youtube.com/watch?v=2ZSI3pKNpLo
If I’m thinking of some symbiosis, the sound, sight and shadow of the boats probably scares the fish out of hiding/camouflage, which makes them easier for the cormorants to catch. And then humans figured out how to train the cormorants following the boats and gobbling up all the fish.
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy: