Blue Holes as Freshwater Oases?

Antillean Nighthawk taking a drink before flying off into the night to forage

Antillean Nighthawk taking a drink from a blue hole before flying off into the night to forage

We often hear about inland blue holes as a window to the past. The anoxic conditions found deep in these vertical chasms has preserved the skeletons of numerous extinct animals including tortoises and crocodiles (link and link). Combined with a very limited number of freshwater sources elsewhere among the karstic bedrock of The Bahamas, these fossils suggest that these vertical caves were probably a valuable source of fresh water for historical animal communities. I suppose somewhat akin to the water holes in Africa, although that’s probably a bit of a stretch. But are blue holes important today? How important and to which animals? Here are a few observations that suggest that contemporary animal communities might rely on blue holes.

Birds are the most obvious visitors of blue holes; Blue-winged Teal, White-cheeked Pintails, Pied-billed Grebes, Least Grebes, Bahama Swallows, Antillean Nighthawks, Grey Kingbirds, and Loggerhead Kingbirds can all be found in and around these freshwater habitats. They can be so abundant around blue holes that it’s not uncommon to see dozens or even hundreds of birds scooping water from the surface of inland blue holes. The nighthawk above was just one of over 20 drinking before taking off into the forest to forage for the night.

Conserving blue holes is important for ensuring that the history of Abaco, and the Greater Caribbean is preserved and available in perpetuity. The point of this quick post is to make a brief argument for the preservation of blue holes (and other freshwater habitats) based on their contemporary function as freshwater oases for Abaco’s forest and wetland wildlife.

Links to past Blue Hole posts:



By | 2017-12-01T14:03:46-05:00 June 18th, 2013|Categories: Archaeology, Birds, Blue Holes, Caves|2 Comments

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  1. Avatar
    Rava June 18, 2013 at 4:40 pm

    Are the blue holes not also connected to the aquifer where the well water come from? If so, it is also very important to the human animals. I have seen some blue holes used as dumps with the potential to pollute the drinking water we all use.
    The Abaco Scientist Rocks , by the way…..

  2. Avatar
    Sean Giery June 18, 2013 at 4:54 pm

    While I’m no hydrologist, I do believe that blue holes are often part of the aquifers that Abaconians draw upon for their water. It’s also true that many are quite polluted. ‘The Old Place’ up near Cooperstown is one that comes to mind. There’s at least one vehicle in there and probably much more below the (very murky) surface. Others have assorted clothes washers and refrigerators, but many are rather pristine. I do see many more birds and other aquatic life in and around blue holes without abundant garbage, but I’m not sure that I would draw a connection without more study. That said, heavy metals from dumped garbage in the aquifer seems bad for whoever drinks it.

    Thanks Rava!

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