We’ve packed and left Glover’s to perform one last tour of the Carrie Bow Cay and a final dive in the Twin Caye mangroves, a habitat with unique saline-tolerant trees that not only serve as a great fish nursery from many ocean fishes, but also as a carbon reserve that takes more CO2 from the atmosphere than many other tree biomes, making their conservation a priority. While the insides of mangroves are oxygen poor and harsh, the edges of a mangrove forest harbor diverse life forms ranging from sponges, to juvenile fishes, to magnificent feather duster worms, and most importantly to me, jellyfishes.
The mangroves are carpeted with two species of jellyfish: Cassiopea frondosa and Cassiopea xamachana. These guys are also known as upside down jellyfishes, since they orient their tentacles upwards to energize the photosynthetic symbionts that live in there, similar to how corals foster photosynthetic algae in their polyps. These symbionts give each jellyfish a different color, ranging from yellow to orange to even green. With the hundreds of jellyfishes that lay on the sea floor, it was almost like a carpet mosaic. Adrienne, one of our instructors this trip, wondered why more jellyfish hadn’t adopted this kind of lifestyle, considering how numerous and successful the upside down jellyfishes were. We also wondered whether these guys could be a transition between sedentary polyps that have symbiotic algae and free-swimming jellyfishes that feed on prey. I need to brood on these questions for a bit, but I’m not sure I’ll find an answer to this evolutionary problem.
For now, I need to consolidate my thoughts on the fact of leaving the country. I’ll make sure to update you all on my final thoughts and musings. Definitely felt a lifetime pass in just two weeks and can’t wait to share all the pictures!