More inexplicable masses of dead. I can personally attest, since I have been to the beach several times on the Jersey Shore this week, that the water is a fetid, murky shade of dung, and brown foam bubbles several inches high whenever a wave recedes, leaving a stain on the sand. Ugh!
Not that it is connected with fish die-off, of course. I wouldn't want to be unscientific, and suggest that pollution has anything to do with it.