Expanding Public Knowledge of New Ecosystems Through Saltwater Cave Research

Updated: Apr 16, 2021

Knowledge of the world as we know it is constantly growing, with innovations appearing daily. The least known and poorly understood part of our planet remains to be the ocean.

When we think of unexplored parts of the oceans, most people’s first reaction is to think of the deep sea. Nevertheless, other parts of the ocean are still relatively unknown and unexplored.

Dr. Thomas Iliffe, a world-renowned cave diver, scientist, and professor at Texas A&M University at Galveston, has dedicated his life to researching and exploring underwater cave systems.

“Saltwater caves located along the coast are tidal with the water rising and falling every time the tides in the sea go up and down,” Iliffe said. “Although the surface waters are typically freshwater, if we put on our diving gear and go down to deeper waters, we find saltwater with the same salt levels as the ocean.”

Iliffe noted that exploring these underwater caves, which initially started as a hobby for him, eventually turned into his life’s work.

“When I first started cave diving, it was out of curiosity. I saw these unusual, very clear saltwater pools inside dry caves,” Iliffe said. “No one had ever investigated them or looked for animal life in them, so together with several friends, we took take a cave diving course and began diving in them. Down in the deeper saltwater, we found all sorts of unusual animals swimming around.”

The animals Iliffe discovered were especially unusual in that they had no eyes or pigment. This prompted him to send these specimens to the Smithsonian Institution in Washington, D.C.

“These experts at the Smithsonian told me that not only did the specimens come from a new species, they also represented a new and previously unknown order of crustaceans that we named Mictacea,” Iliffe said.

Order refers to a level in the biological classification of life, with examples including Primates (apes and humans), Carnivora (meat-eating mammals), and Chiroptera (bats).

“With my work, I’ve now discovered more than 250 new species, plus many new higher groups of animals coming exclusively from these types of saltwater caves. Hardly anyone, anywhere knew anything about these environments before we started doing our cave diving work in them,” Iliffe said.

Iliffe’s magnificent discoveries led the International Union for Conservation of Nature (IUCN) to invite him to add chapters on subterranean ecosystems to their latest publication.

“This new book from the IUCN lists and describes all of the ecosystems on planet Earth,” Iliffe said. “There are 108 different ecosystems listed in the book and I collaborated on authoring 10 of the chapters on subterranean ecosystems.”

This was a chance to collaborate and share his research with other scientists globally, it was an honor and the experience of a lifetime for Iliffe.

“It was a great pleasure to be able to work with these renowned scientists. They contacted me to ask if I would be willing to participate and I jumped at the chance,” Iliffe said. “This book provides essential information for students, conservationists and land managers to properly gauge the significance and interactions of each of the Earth’s ecosystems.”

Even after 40 years of researching these seawater-filled caves, Iliffe knows that his studies are only in their infancy with much work still needing to be done.

“Were at basically page one of the book. We have so much to learn, so much to do,” Iliffe said. “Every time I discover something or find something new and answer one question, it opens up a dozen more questions. It’s very exciting work that I could spend 100 lifetimes on and still not have come close to scratching the surface of discovering all that’s down there.”

For more information, contact Iliffe at iliffet@tamug.edu You can also download the IUCN book at https://portals.iucn.org/library/sites/library/files/documents/2020-037-En.pdf or view its companion website at https://global-ecosystems.org/.

See Dr. Thomas Iliffe's gallery of these sea caves.