PANDORA MELMAK CONNECTION
PANDORA & MELMAK
Our team has been exploring Sistema Pandora for for the past few years. The original explorers of the system were Natalie Gibb, Vincent Rouquette-Cathala, and Steve Bogaerts. Cenote Melmak is a new project that we first dived in January 2017. As of January 2017, Pandora and Melmak were about 500 meters apart. The first goal of this trip was to continue our eastbound end of line from Melmak, as well as to push west from the cenote towards Steve´s 2016 end of line at Pandora. The second goal of this trip was to introduce Dr. Patricia Beddows to the region, and to document the unusual bacterial for potential scientific endeavors.
ACCESS AND LOGISTICS
One of the challenges of exploring Pandora and Melmak is logistics. Pandora requires boat travel, as it is a shallow entrance in a mangrove region, and boat rentals were becoming prohibitively expensive. Melmak is located on a military base, and requires official permission to dive. It took us almost a year to return to these explorations, while we worked to solve these logistical difficulties. We now have contracted with a private captain for Pandora, and have received official and exclusive written permission for exploration on the military base for the next 8 years. Hopefully this means that we will be returning to Pandora more frequently in the future.
The Pandora-Melmak connection was made over the course of three days.
CONNECTION DIVES
STARTING POINT
This region map illustrates Pandora and Melmak’s surveyed lines from January 2017. The easternmost line of Pandora is Steve’s 2016 end of line, called the “Harry Twat” line. Cenote Melmak was only explored in an eastern direction from the main pool with the most promising lead being Natalie and Vince’s end of line at the Vaquero line, which opened into huge, blue, saltwater passage at around 65 feet of depth.
PUSHING EAST
On the first day of the expedition, the team split up. Natalie went to Pandora with Dr. Patricia Beddows and Rory O´Keefe, to document the bacterial formations and growth. Vince and Marcelin went to Melmak, and continued from the Vaquero end of line placed last January. Although the cave continues, its becomes smaller relative to the overall passage size and does not appear to be the main passageway. Two segments of line were added, the Car Key Line (because Vince had managed to lose his car keys in the ocean) and the Airplane line. We will continue to push from this area in the future.
CONNECTION PUSH DAY 1
The team decided to push west from Cenote Melmak towards the Hairy Twat line on the second day of the expedition. While Marcelin and Vince were lowering gear, Nat did a quick reconnaissance dive down the western facing slope from the cenote. The western entrance is a vertical restriction, but opens up into massive cave almost immediately. The team carried side mount cylinders and stuck together until Vince found lead heading north and took off to check it out. Nat and Marcelin went nearly due west towards Pandora, on the Road to Pandora line, and Vince headed north emptying his reels in Bil’s Passage. Both tunnels average 10-15 meters wide, and continued. Even on 32% nitrox, we had a bit of deco as average depths were around 65 feet. It was decided to bring oxygen for decompression the next day.
CONNECTION PUSH DAY 2
The second day of the connection push got complicated, but was successful. The team decided to stay together (we all wanted to see the connection). This time we took scooters, so we set up an underwater relay to ferry the scooters, camera, lights, oxygen bottles, and stages down through the entry restriction. Arriving at the end of line on the Road to Pandora, we dropped the scooters and stages. Marcelin had the reel, with Vince buddying with him, while Nat lagged behind a couple of stations, using our mNemo to survey on the way in. This technique allowed us to explore on thirds, and freed us to do some filming over our newly laid line on the way out (which is what you see on the video above). We turned when we reached our turn pressures, having emptied a little over one reel on the Guey line, and finishing in a very tannic dome with reduced visibility. We did not connect to Pandora, but when we mapped it was discovered that the Hairy Twat line should be no more that 50 feet away from where we turned. So close, and yet so far away.
CONNECTION PUSH DAY 3
With one day left, we were determined to connect Pandora and Melmak. This time, we carried two stages and one scooter each, to allow plenty of gas for the connection. The team split, with Vince and Nat attempting the connection, and Marcelin heading to the end of line at Bil’s Passage to see if he could continue to push north. When Nat and Vince arrived at the end of the Guey Line, it was discovered that Vince had lost his exploration reel. With an over abundance of gas, but little line, Nat used her smaller exploration reel to look for the connection, which was discovered only about 20 feet from the end of the Guey Line. The water was so tannic that there was only about 5 feet of viz and it was impossible to see the Hairy Twat line until we were right up on it. Nat and Vince also laid a little line in a huge southern lead, while Marcelin emptied both his reels heading north, on the Red Light District section. The Pandora-Melmak connection brings Sistema Pandora up to 8.256 kilometers, with plenty of going leads for future trips.
BACTERIA
Dr. Beddows examines bacterial flakes.
BACTERIA
Sistema Pandora is covered with dense bacteria growth. On the walls and ceiling, we observed web-like coverings and bacterial straws. The floor is covered with bacterial “sediment” that has a jello–like consistency. The floor sediment is at least a meter thick in most places. Areas where the floor has slid apart or cracked reveal multicolored layering or growth patterns. This layering is also present in the sediment “rocks” found some areas. The color of the bacteria varies: dark gray, beige, light gray, and green. Pandora is full of hydrogen sulfide which we would guess is related to the bacteria’s life cycle in some way.
Web-like bacteria coat Pandora’s Walls.
A bacterial “brick” with layering visible.
Bacterial straws reach several meters in length.
THE CAVE
Rory O’Keefe in a smaller passage filled with bacterial straws.
PANDORA
In addition to being filled with bacteria and hydrogen sulfide, Sistema Pandora has interesting haloclines and tannic rooms. It is possible to observe a brackish water-freshwater halocline at the Pandora Entrance, which has a milky color. In the cave, we encounter the first halocline at about 55 feet of depth, which is consistent throughout the cave. Bacteria that has flaked off the ceiling often floats just at the halocline, remaining suspending in the water for at least a few hours. As Pandora runs under mangroves, it is also possible to find tannic-water domes — areas where the water has been stained a dark reddish brown from the organic materials above. The visibility in these domes can be quite poor, sometimes as low as 5 feet, which makes scooter through the domes difficult. The tannic areas are above 55 ft, and only found in fresh(er) water above the halocline.
Dr. Patricia Beddows in a smaller tunnel typical of the area near Entrada Pandora.
Marcelin Nebenhaus swims under bacterial suspended in the halocline.
Marcelin Nebenhaus swims past fallen stalactites that have been covered with bacterial growth.
