Connect with us

Marine Life & Conservation

The Yucatan Cenotes – A paradise under threat from tourism



An interview with Sam Meacham by Jeff Goodman

A few years ago I made a film for the BBC called ‘Secrets of the Maya Underworld’ and was about the Cenotes and forests of the Yucatan Peninsula, Mexico. Previously I had always promised myself not to ever cave dive as I had a fear of being lost or trapped far underground with no escape route. Then a few very good friends told me of the Cenotes and the incredible wildlife that was associated with them. I had to see for myself.

Yucatan-Cenotes-2It was then I met Sam Meacham, an American living near Cancun. He had been exploring the caves and passageways of the Yucatan Peninsula for the previous 18 years and now to date has discovered with other divers 252 known caves and cave systems in that region with a total of 1,103.3 km or 685.5 miles of surveyed passageway between them.  Two of the five longest caves on the planet Sistema Sac Actun and Sistema Ox Bel Ha are found close to the town of Tulum.

The Yucatán Peninsula was once a shallow coral reef and now over a few million years has become a porous limestone shelf covered with forest and wildlife. There are no visible rivers; all the fresh water rivers are underground. Being porous, caverns and caves formed where the fresh water collects – hence the Cenotes or water sinkholes.

Recently, the Cenotes have become a great dive destination and the eastern Yucatan coastline an ever developing tourist area for sun worshipers and beach goers. The seemingly uncontrolled developments are taking their toll on this unique ecosystem.

I recently got back in touch with Sam to see if things were improving.

Jeff:  Can you just tell us exactly what the Cenotes are and what is so special about them?

Sam: Cenotes are karst sinkholes that occur in Mexico’s Yucatan Peninsula.  The Cenotes are windows into the freshwater aquifer of the region and the entrances to the very complex flooded solution cave systems along the Caribbean coastline.

Yucatan-Cenotes-3Jeff:  The underground water systems give life to the forests above where wildlife is obvious to find, but is there life in the caves as well?

Sam: Most people think of the cave environment as a very sterile place.  In fact, there are over 40 life forms so far identified that live in the dark recesses of these caves.  The majority are crustaceans and they are all considered extremeophiles because of the conditions they live in.  The Cenotes themselves are also magnets for life; this includes a number of freshwater tropical fish species, crocodiles, turtles in the water and birds and mammals (including jaguars) at the surface.

Jeff: How long has man know about the Cenotes?

Sam: There is growing evidence that the caves and Cenotes were accessed by humans during the last ice age, which was 8000-10000 years ago.

Jeff: Did the Maya have any idea about the complexity of the underground waterways?

Sam:  It is hard to say if the Maya realized that some of the Cenotes were connected by the intricate and complex cave systems. Many of the underground rivers flow out to the sea in very impressive upwellings; perhaps they put two and two together when they observed this.  It was not until the 1980’s that cave divers really began to probe the depths of the Cenotes and really revealed just how complex and extensive they were.

Jeff: Are the Cenotes and reliant ecosystems in any threat now due to the commercial tourist developments?Yucatan-Cenotes-4

Sam: There is a very real and continuing threat from the development of the tourism industry along the coastline.  Karst landscapes like the Yucatan are very susceptible to contaminants that leach through the porous limestone and into the aquifer.

Jeff:  What are the main issues?

Sam: The main issues we face are contamination from solid waste (garbage) and sewage.  Once contaminants hit the aquifer there is the high potential for them to be transported through cave conduits and out to the Caribbean Sea.  High concentrations of contaminants cause algal blooms that cover the Mesoamerican Reef and kills the corals.  If we lose the reef, we lose the protection to the beaches.  If the beaches erode, where will the tourists go?  Effectively, we risk killing the goose that lays the golden egg.

Jeff:  Is anyone listening to the conservation needs of the area or is commercialism taking its full toll?Yucatan-Cenotes-5

Sam: Well, I think worldwide conservation efforts are always facing an uphill battle and this area is no exception.  But I do think there is a great deal more awareness about the existence and importance of the flooded caves.  My personal belief is that the outreach and education about the caves is the only way we can engage the public and effect change.

Jeff:  As Divers, how can we help preserve this unique ecosystem?

Sam: If you dive in the Cenotes, it is a great opportunity to perfect your skills particularly your buoyancy and trim.  Really, any time you go diving you should be perfecting your skills.  We, as divers, are privileged visitors to the underwater environment and must make every effort to protect it.

Jeff:  If readers want to learn more where can they get further information?

Sam:  Here are a few websites:

Jeff is a multiple award winning, freelance TV cameraman/film maker and author. Having made both terrestrial and marine films, it is the world's oceans and their conservation that hold his passion with over 10.000 dives in his career. Having filmed for international television companies around the world and author of two books on underwater filming, Jeff is Author/Programme Specialist for the 'Underwater Action Camera' course for the RAID training agency. Jeff has experienced the rapid advances in technology for diving as well as camera equipment and has also experienced much of our planet’s marine life, witnessing, first hand, many of the changes that have occurred to the wildlife and environment during that time. Jeff runs bespoke underwater video and editing workshops for the complete beginner up to the budding professional.


The Ocean Cleanup to Complete 100th Extraction Live from the Great Pacific Garbage Patch



the ocean cleanup
  • The Ocean Cleanup marks 100th extraction of plastic pollution from the Pacific Ocean by livestreaming entire cleaning operation from start to finish.
  • Occasion brings together supporters, partners, donors and followers as the project readies its cleanup technology for scale-up.
  • Founder and CEO Boyan Slat to provide insight on the plans ahead.

The Ocean Cleanup is set to reach a milestone of 100 plastic extractions from the Great Pacific Garbage Patch.

Extraction #100, scheduled for 28 or 29 May 2024, will be the first ever to be livestreamed direct from the Pacific Ocean, allowing supporters and partners around the world to see up close how the organization has removed over 385,000 kilograms (nearly 850,000 lbs) of plastic from the GPGP so far – more than double the bare weight of the Statue of Liberty.

the ocean cleanup

The mission of The Ocean Cleanup is to rid the oceans of plastic. To do this, the non-profit project employs a dual strategy: cleaning up legacy floating plastic in the Great Pacific Garbage Patch (the world’s largest accumulation of floating plastic), while stopping the flow of plastic from the world’s most polluting rivers.

The Ocean Cleanup captured its first plastic (the first ‘extraction’) in the GPGP in 2019 with System 001, following years of trials and testing with a variety of concepts. Through System 002 and now the larger and more efficient System 03, the organization has consistently improved and optimized operations, and is now preparing to extract plastic trash from the GPGP for the 100th time.

the ocean cleanup

Extraction #100 will be an interactive broadcast showing the entire extraction procedure live and in detail, with insight provided by representatives from across The Ocean Cleanup and partners contributing to the operations.

This is an important milestone in a key year for The Ocean Cleanup.’ said Boyan Slat, Founder and CEO of The Ocean Cleanup. ‘We’ve come a long way since our first extraction in 2019. During the 2024 season, with System 03, we aim to demonstrate that we are ready to scale up, and with it, confine the Great Pacific Garbage Patch to the history books.

the ocean cleanup

The livestream will be hosted on The Ocean Cleanup’s YouTube channel and via X. Monitor @theoceancleanup for confirmed timings.

Continue Reading

Marine Life & Conservation

Dive with a Purpose: Shark Guardian’s Expedition Galapagos



Shark Guardian has just unveiled their largest and most exciting expedition yet: a seven-night, eight-day adventure in August 2026 aboard the Galaxy Diver II, a state-of-the-art
vessel specifically designed for divers exploring the enchanting waters of the Galapagos
Islands. This is a once in a lifetime opportunity to engage deeply with marine
conservation in one of the world’s most revered diving destinations.

Shark Guardian is a UK registered charity dedicated to protecting sharks and marine
ecosystems worldwide. Founded by marine biologists and conservationists, Brendon
Sing and Liz Ward-Sing, Shark Guardian leads educational programs, research projects,
campaigns and expeditions aimed at fostering a better understanding and respect for
marine life. Their work spans several continents and focuses on direct action,
education, and advocacy.

Shark Guardian’s ethos revolves around the concept of “diving with a purpose.” This
philosophy underscores the importance of not just experiencing the wonders of the
underwater world but actively learning and contributing to its preservation. Participants
in Shark Guardian expeditions engage in citizen science projects, which involve
collecting data that supports ongoing research and conservation efforts. These
activities empower divers to make a tangible difference, turning each dive into an act of

One of the newer additions to the Galapagos diving scene, the Galaxy Diver II, is
specifically tailored for divers. Its design prioritises comfort, safety, and environmental
responsibility. The vessel boasts modern amenities, spacious dive decks, and the latest
navigational technology, ensuring that every dive is not only memorable but also has
minimal environmental impact.

A highlight of this expedition is the opportunity to dive at Wolf and Darwin islands,
renowned for their vibrant, untouched marine ecosystems and as a haven for large
pelagic species. These islands are famous for their schools of hammerhead sharks,
whale sharks, and manta rays, offering spectacular diving that attracts enthusiasts from
around the globe.

Shark Guardian have developed this trip to ensure a hassle-free experience. The
expedition package also includes internal flights from Quito, Ecuador, to the Galapagos,
plus accommodation in Quito before and after the trip. This allows divers to relax and
enjoy the experience without worrying about logistics.

Participants will join a diverse group of passionate divers and conservationists. This trip
offers a unique opportunity to network with like-minded individuals who are eager to
learn about and contribute to marine conservation. It’s a chance to share experiences,
knowledge, and a commitment to protecting the marine world.


Shark Guardian is offering an early bird price available until May 31st 2024. This special
rate provides a fantastic opportunity to secure a spot on this exclusive expedition at a
reduced cost. Availability is limited, so interested divers are encouraged to act quickly
to ensure they don’t miss out. All the details can be found on their WeTravel page, where
bookings can be made easily and payment instalments are available.

Expedition Galapagos, aboard the Galaxy Diver II offers more than just a diving
holiday—it is an investment in both personal and planetary well-being. By participating,
divers not only witness the majesty of one of the world’s premier diving locales but also
contribute to its preservation for future generations.

Find out more about Shark Guardian at

Continue Reading

E-Newsletter Sign up!

Experience the Red Sea in May with Bella Eriny Liveaboard! As the weather warms up, there’s no better time to dive into the crystal clear waters of the Red Sea. Join us on Bella Eriny, your premier choice for Red Sea liveaboards, this May for an unforgettable underwater adventure. Explore vibrant marine life and stunning coral reefs Enjoy comfortable accommodation in our spacious cabins Savor delicious meals prepared by our onboard chef Benefit from the expertise of our professional dive guides Visit our website for more information and to secure your spot: or call 01483 411590 More Less

Instagram Feed