Welcome to an initiative by the AAUS to spotlight organizational member projects and divers. Articles will not only be featured here but also in the E-Slate and
AAUS social media.

To join us in spotlighting our community, please complete the form at the bottom of the page or send your articles and photos to

Please be sure that all photos/articles have credits if required.

Home Page /images/AAUS/Headers/News_Articles.jpg

Researchers Embark to Explore Mysterious 'Blue Hole' Hidden Off The Coast of Florida

When sinkholes open up on land, it's terrifying. In an instant, they can swallow whatever's on top of them, whether that's a road, a landscape, or an ancient creature destined to not see the light of day again for millennia.

Sinkholes aren't just confined to land, though. A similar phenomenon also takes place in the ocean, creating mysterious 'blue holes' that plummet into dark, watery nothingness. Distinct from the underwater caverns of cenotes, which exist under land, blue holes only open up in the sea, making them much more difficult to explore and understand. Nonetheless, they represent a valuable opportunity for scientists seeking to learn more about what kind of life-forms and underwater conditions occur in these unique marine formations.

As part of an ongoing three-year research project, a multi-institutional team of scientists is set to embark next month to explore a blue hole called 'Green Banana' situated on the continental shelf off the coast of Florida. .Comprising researchers from Mote Marine Laboratory, Florida Atlantic University, the Georgia Institute of Technology, and the US Geological Society, the NOAA-sponsored project will deploy divers and monitoring equipment into Green Banana, which opens up 47 metres (155 ft) below the sea surface, extending to a depth of about 130 metres (425 ft).

The aim is to examine what kind of microbes live in the blue hole, measure nutrient levels in the underwater column, and assess whether the sinkhole is somehow connected to Florida's groundwater system adjacent to the Gulf of Mexico.
After August's dive, another is scheduled to take place next year, following up on research expeditions last year to investigate another Florida blue hole, called Amberjack Hole, which is significantly smaller than Green Banana – with a rim at 34 metres (113 ft) below the ocean surface, and extending down for about 72 metres (237 ft) below that.

"Blue holes are diverse biological communities full of marine life, including corals, sponges, mollusks, sea turtles, sharks, and more," the NOAA explains. "The seawater chemistry in the holes is unique and appears to interact with groundwater and possibly aquifer layers. This link contributes to the knowledge of carbon cycling between surface and groundwater."

It might be a while before we hear more on the Green Banana expedition, but samples recovered at Amberjack Hole have already shown large amounts of dissolved inorganic carbon in the water, which the researchers say contributes to the carbon cycle, possibly as a food source for microbial populations. There were also signs of nutrient flux travelling upwards in the sinkhole, meaning that some food sources could eventually emerge from the blue hole, even while other creatures – including deceased sawfish discovered by the researchers – slowly sink to the bottom. Last year's dives also isolated signals of groundwater in the blue hole, finding isotopes of radium and radon, which suggest there could be an underwater connection linking the Floridan Aquifer to the Gulf of Mexico.

Whether the Green Banana can corroborate that signal remains to be seen, but whatever the researchers find, it's bound to help us better understand what goes on inside these strange sinkholes hidden below the surface.

Peter Dockrill, 21 July 2020
Reprint from  

Past Spotlights

Implementing Closed Circuit Rebreathers as an Underwater Science Tool: A Case Study from the Middle

Since the introduction of closed-circuit rebreathers (CCR) to the commercial market in the mid 1990s, this technology has opened new frontiers to diving scientists while dramatically expanding the capacity for conducting underwater research within re

Seaweed Wars: Return of the Giant Kelp

A long time ago, in an ocean not so far away, a boat jetted across the calm swell of Point Loma. However, under the surface of the rolling waves a silent battle was raging. Algae just under the surface are locked in a constant fight for light and spa

Investigating the effects of local stressors on the life cycle of a brooding coral

Sunlight enters the lab as I sit down to peer through the microscope. I always make sure to slowly increase the light, adjust the ocular lenses, set the magnification to 4x, and look carefully. After some fine adjustments, microscopic circular object

Genetic diversity and resilience of corals in the genus Pocillopora

FSU researcher Dr. Scott Burgess and his team visited the island of Moorea this summer to survey and collect samples on tropical coral reefs. Partnering with Dr. Pete Edmunds of CSUN, Dr. Burgess will shed light on the genetic diversity and resilienc

Scientists create largest collection of coral reef maps ever made

A study from scientists at the Khaled bin Sultan Living Oceans Foundation and the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science offers a new way to accurately map coral reefs using a combination of Earth-orbiting satell

Latest News

John Pearse (1936-2020)

Posted on 8/30/2020

2020 Conrad Limbaugh Award Recipient

Posted on 8/30/2020
The 2020 AAUS Conrad Limbaugh Award for Scientific Diving Leadership goes to Lloyd Austin.

Zale Perry Scholarship 2020

Posted on 7/30/2020