Answer:

redtide

AnswerCrossword Clue
REDTIDEOcean phenomenon associated with wildlife mortality
REDTIDEShellfish contaminant
REDTIDESeawater discolored by dinoflagellates
REDTIDEDanger to shellfish
REDTIDEDangerous ocean phenomenon
REDTIDEShellfish bane
REDTIDERecurring marine phenomenon
REDTIDEDangerous algal bloom
REDTIDEPotential beach closer
REDTIDEFisherman's bane
REDTIDEBeach-closing phenomenon
REDTIDEPhenomenon caused by a bloom of dinoflagellates
REDTIDEReason not to go swimming in the ocean
REDTIDEColorful beach sighting