At a Glance

Richard Branson, Fabien Cousteau and Erika Bergman's expedition found plastic pollution at the bottom of the Great Blue Hole.The crew found plastic bottles at the deepest point of the sinkhole.Branson hopes the find will raise awareness for protecting the ocean and reacting to climate change.

Back in early December, Richard Branson and Fabien Cousteau manned the first ever submersible dive , part of one of the world's largest coral reefs — the Mesoamerican Reef.

What they found at the very bottom of the world's largest sinkhole? Well, it's pretty saddening.

Branson and Cousteau along with Erika Bergman, their submersible pilot, found that even the deepest parts of one of the most mysterious places on the planet can't avoid plastic pollution.

(MORE: Aspen-Area Avalanche Kills One; Special Avalanche Advisory Issued)

"As for the mythical monsters of the deep? Well, the real monsters facing the ocean are climate change – and plastic," Branson wrote in a journal of his dive. ", which is a real scourge of the ocean."

The unfortunate reality that Branson's expedition shows is that no place is safe from plastic pollution — , the deepest natural point in the world (over 87 times deeper than the Great Blue Hole at 35,755 feet deep), or the Great Pacific Garbage Patch, meant to clean it up.

Branson also made note of the visible changes in the rock that marked where the once dry land caves were submerged and consumed by the ocean, calling it "one of the starkest reminders of the danger of climate change" he had ever seen.

Along with the discovery of the bottles, the crew found crab, conches and other critters that had fallen to the bottom of the sinkhole and died from lack of oxygen below a thick layer of Hydrogen Sulphide.

"Hopefully by this trip taking place we have raised even more awareness of the need to protect the ocean and tackle climate change now – before it is too late," wrote Branson.