Trip Report Poor Condition of Bahamas Reefs

[arkstorm]

I got to spend a wonderful week on the Aqua Cat live-aboard in the second week of August, 2025, and while the boat and the crew were amazing beyond all expectations, most of the reefs we visited were overrun by a dense layer of algae that seemed to be decimating the corals.

In the most heavily affected areas, the drab blanket of algae left a hellscape where fish and other wildlife were scarce.

The good news is that not every reef was affected, but in my estimation, 75-80% of the reefs were in extremely poor condition.

I shutter to think what the future of diving in the Bahamas (and elsewhere) is going to look like if this devastation continues.

 

[fish_defender]

What did the algae look like? Do you have any footage? What locations did you visit?

 

[also_anon_dc]

This is what most of the Caribbean has looked like the past few years. Have you been diving elsewhere in the Caribbean that doesn't look like this?

I'm not a marine biologist but I don't think the algae is killing the coral. The coral dies because of pollution, water temps or disease and then the algae takes over.

 

[tarponchik]

This is what most of the Caribbean has looked like the past few years. Have you been diving elsewhere in the Caribbean that doesn't look like this?

I'm not a marine biologist but I don't think the algae is killing the coral. The coral dies because of pollution, water temps or disease and then the algae takes over.

Exactly. However, most likely, algae growth is promoted by polution. Washed-off fertilizers, phosphorus in laundry detergents and human waste and so on.

 

[sea_ledford]

This is a common problem in areas with heavy tourism. It is from an influx of nutrients from sewage and run-off, as @tarponchik said. It is called eutrophication. The algae thrives in the nutrient rich waters and can outcompete the coral, especially when the coral is already stressed from other environmental issues like high temperature.

I did my Masters thesis on this in the Yucatan in 2002. It was very obvious comparing the Akumal area (already high impact at that time) to the Siaan Kaan Biosphere Reserve south of Tulum (very low impact for the region). That was when Tulum was about 6 dirt roads. I suspect most of the Yucatan is pretty over grown with algae now. Tulum will only get worse with the trains. That environment just can't handle the number of people there. Geologically, the Bahamas is the same way, porous limestone is pretty bad at filtering sewage so may as well be dumping raw sewage straight into the ocean.

There seems to be no work on addressing this in any sort of meaningful way, so it will just continue to get worse. We have known it is a problem for over 30 years, probably closer to 50. Why save the reefs for later when we can make money on cruise ships and tourists now?

It's a big fat bummer.

 

[Flatline]

How are Bonaire and other places that are more controlled? I would imagine they have less algae from runoff?

 

[arkstorm]

This is what most of the Caribbean has looked like the past few years. Have you been diving elsewhere in the Caribbean that doesn't look like this?

I'm not a marine biologist but I don't think the algae is killing the coral. The coral dies because of pollution, water temps or disease and then the algae takes over.

I’ve been diving elsewhere in the Caribbean, e.g., Turks in November, 2024, and it didn’t look like this.

I’m not a marine biologist either, but I was told that the algae IS killing the coral. It’s like a 4-inch thick blanket on the coral which prevents the coral from getting any nutrients or sunlight.

Just sad really.