Nancy Albury is the Abaco Manager and Curator of Paleontology for the National Museum of the Bahamas. She is responsible for management of the natural history collections as well as documentation and research of the blue holes, cave sites, and their fossil assemblages.
Expedition Blog 7 / Dec. 10 / By Nancy Albury
When I was a child, I was intrigued by a large cave on New Providence Island here in the Bahamas. After pestering my mother for years, we finally took a trip to see it. I remember standing in the cave for the first time, spellbound in the darkness as the bats fluttered past me like fairies in the dim light of my headlamp. It never entered my mind to be afraid of what might be in this dark place. Rather, I was hooked, captivated by the cave’s beauty and the mysterious animals that lived within.
It was later during college that I began cave diving. My diving buddies and I would sneak across cow pastures so we could dive a forbidden cave—a considerably greater level of excitement for me than the typical college merriment. And for the past 11 years I have worked for the National Museum of the Bahamas, a job that has given me the opportunity to explore, study, and document the dry and flooded caves in the Bahamas, referred to as “blue holes.” These blue holes have remained my personal happy place over these many years—quiet secretive spaces that hide the mysteries of our natural world.
Blue holes are time capsules that contain some of the most intriguing collections of natural, geologic, and human history in the West Indies. Diving in the crystalline passages of a blue hole is the equivalent of time travel. Like reading chapters of a book, history unfolds in the rock wall’s layers of sand, coral, and shells. Speleothems (stalactites and stalagmites, etc.) and bottom sediments hold a rich history of sea level, climate change, and the remains of plants and animals. All of these reflect the surface ecology of the time when they were deposited.
My real passion is the fossils—some over 4000 years old—of a variety of animals that are extinct and give us clues about how the ecosystems functioned before human occupation. Through the millennia, animals that came to drink became prey or fell into the blue holes as they drank. Trapped and treading water, their ultimate fate was to drown and sink into the dark anoxic bottom sediments, mixing with wind-blown leaves and vegetation that grew around the blue hole during the same time.
The growing list of species that we’ve recovered from these holes indicate it was a reptilian ecosystem, dominated by giant tortoises, crocodiles (the apex terrestrial predators of their day), large rodents known as hutia, numerous species of birds (many now extinct), including some that were flightless. Other forms of evidence including seeds are used to reconstruct the past vegetation and how the environment has changed through time.
Blue holes were dry caves during the Pleistocene Ice Ages and were home to bat colonies and giant owl roosts who left left behind the skeletal remains of their meals. Later, during the higher sea levels of the Holocene period, the remains of mammals, birds, reptiles, and fish also became entombed. Lucayans, the earliest humans in the Bahamas, who have no living descendants, were no less mystified than we are today and there is skeletal evidence of these paleoindians preserved in the anoxic salt water. They revered blue holes and caves as spiritual portals to the world beyond life, using them as places to bury their dead.
A friend of mine spent his life exploring the caves and finding prehistoric sites on Abaco. For years, he was hesitant to document the sites he’d found. Sadly, he recently passed away along with too much of his life’s work. I understood his reserve; the double-edged sword of exploration and discovery is the threat of its destruction and looting. However, the best conservation often starts with education about the value of these places that is not always self-evident. I was immediately supportive of this National Geographic project when proposed because it had the rare combination of innovative outreach, mapping, and image collecting that can help further The Museum of the Bahamas’s goals of making these hidden realms accessible to the public.
The incredible response from the children that we’ve taught this week is evidence of the team’s effective hands-on activities. Watching their faces light up with those special “ah-ha” moments was a flashback to the childhood adventures that inspired my own love of caves. I’m sure the children who have visited the site this week will remember these real life learning experiences for a lifetime and become tomorrow’s citizens who know and appreciate our natural history.