I would say coral bleaching sometimes cause by toxic algae/bacteria caused by pollution. I would say same ones causes ciguatera fish poisoning since it prefers warmer water. Since HUMANS cannot be eliminated, what is needed is either more aggressive seagrass/eelgrass that absorbs more nutrients and/or dredging to make current take out more nutrient away from the bay.
Of course acidification too. So either case seagrass helps alot.
It reduces pollution, co2.
It creates sanctuary for tiny fishes as well as food for turtles.