So I just returned from a week of diving hitting all the major sites. My last trip was in Nov2019.
The reefs were horrifying in 2019 as the corals were bleaching due to the disease. Seeing all those bone white coral skeletons was not great.
Fast forward, all those corals are dead and algae has overgrown the coral skeletons so the reef looks "better" but that assessment is certainly relative.
However, the big change I see now is the nutrient load on the reefs. Their is algae everywhere growing on everything and most corals are in various states of being smoothered. I observed tons of cyanobacteria which are non-photosynthetic that feed off poor water quality. This is the rusty/snotty red/brown film you see on the sand bed everywhere. If you notice, it creates a biofilm that actually anchors the sand down keeping it from blowing around in current and smothering everything underneath. Take your hand and wave some water at it and it wont move. Only the very high current areas like the channels in the reef still have that blinding white sand.
I am sure many are cursing the southern hotels but you can see the impacts at the far far southern sites like Punta Sur. Unless the nutrients are circulating around the island (going south down the east coast side) I dont see how the southern hotels can be the primary source of this. Those hotels were also empty over the period I was not there. Same for the cruise ships. Think a source much further source must be considered such as discharge off the mainland.
I raise this because I think this needs to get figured out or those corals are on borrowed time.