I see an incredible preponderance of starfish with extra limbs and what looks like some kind of stag coral. I think the “die-off” was dumping. Maybe local fisherman got frustrated with starfish killing off all the shellfish; if they were particularly ignorant, that could even explain all the starfish with 6 or more arms... but then some species of starfish NORMALLY have 6, 7 or 9 arms.
If local fishermen dumped to kill the starfish, they sure killed a lot of molluscs at the same time.
Climate change — that’s all.
Looks like good surfing.