Similar situation. I volunteered at a wildlife rehab and we got a pelican in. Someone left a wheelbarrow full of fish covered up out in the sun for a few days. I had to clean it out. I did not have a good time.

I once left a plastic tub of bird seed next to the shed one winter. Something chewed it’s way through the plastic, got stuck and died. Since there was now a hole the rain turned it into a weird soup that I discovered during the hot summer. I can’t even imagine the smell if that was anchovies, it was bad enough as it was.