Our Yucatan Forest Journey With Mangroves and ‘Blue Carbon’
The Ellis family is spending the summer “Chasing Carbon” in Southern Mexico while Dad and Forest Carbon Scientist, Peter Ellis, works for The Nature Conservancy to measure the carbon stored and emitted from forests.
During our first week in Mérida, we spent our days adjusting to the climate and absorbing the culture of the Yucatan. Trips to the mercado for vegetables have felt adventurous in the 95-degree heat. We developed a keen radar for shade, water and air conditioning.
On our second day in the country we found our way to Chichen-Itza and the Cenote Ikkil, popular tourist destinations for people off the cruise ships in Cancun. By Day Four, we had been to the local zoo, the Mayan Museum, and the Progreso beach. But the most impressive excursion of the week was on Sunday, when we ventured two hours west to the fishing village of Celestún.
Celestún is a popular ecotourist destination for its abundance of wildlife, most notably the flamingos that gather by the thousands during mating season (December – January). Even in the off season, however, the relatively few flamingos who remain year-round residents are impressive. The salt marsh created by the large estuary that enters the Gulf of Mexico here, allows for dense mangrove forests to thrive, which provide essential habitat for hundreds of species of birds, reptiles and mammals. In the 1980s, the Mexican government designated 600 square kilometers as the Celestún Biosphere Reserve to protect the plants and animals that depend on this ecosystem.
We boarded a boat near the bridge entering town on the lagoon side. The boats are part of an association, with trained guides and a fixed price of 1,200 pesos per boat.
The flamingos, even though there were relatively few, were stunning. I was the first to spot them as a subtle pink line on the horizon. The guide explained that there are relatively few at this time of year (we only saw about a hundred in two different groups), as opposed to December and January when the wetland is filled with thousands who migrate here to court and mate.
We were also impressed by the plethora of other water fowl: osprey, frigate birds, cormorants, egrets, herons, and many others we could not identify (having left the bird guide at home). The sky and trees were filled with them. The guide promised my kids Jasper and Josie a crocodile sighting, which never manifested. After viewing the flamingos our guide accelerated the boat, took a sharp turn, and made a dramatic entrance into what they call “the tunnel,” which is exactly that – a tunnel through the mangroves.
Jasper and Josie had been vaguely interested in seeing the mangroves, after we described them as trees that live on land and water, and essentially make their own islands. But our actual entrance into the “mangal” (as a grove is called) elicited peels of delight. It was breathtaking.
The density of roots and branches, and the way in which the tree transitions from one to the other almost seamlessly, creates a seemingly impenetrable organic fortress. The thick, waxy leaves provide constant shade from the tropical sun. Our guide explained that the deep red tint in the water was a product of a semi-annual release of the red tannins in the bark by the female trees, “like a woman’s monthly cycle,” he elaborated. “But the trees only make this color twice a year.” When I asked why he said simply that it was a natural process that fed the shrimp larvae and boosted the population when the young flamingos were feeding.
The guide had us disembark on a boardwalk so we could get out of the boat and actually walk through the mangal and read interpretive signs explaining the biology of the trees. A young couple was posing for their engagement photos along the boardwalk. As we walked and talked, a few groups of tourists came, took pictures and left. After ten minutes Jasper and Josie ran back to the boat in protest, the excitement of their first impressions having worn off. But Peter couldn’t pry himself away.
“These are really important carbon reserves,” said our resident forest carbon scientist. “But we don’t fully understand them yet.”
It makes sense. The biological networks created by these mangals are dense and can be immense. There are four different species of mangrove found in Celestún and in tropical coastal zones around the world (red, black, brown and white). They make up only 0.7 percent of the world’s forests, but they have the potential to store 2.5 times as much carbon as humans produce globally each year. (“Restoring Mangroves May Prove a Cheap Way to Cool Climate,” Scientific American, July 31, 2012)
Mangroves conserve most of their carbon by building up organic material with their roots into mud and generating soil. There is enormous potential benefit from this type of “blue carbon,” as it is known (as differentiated from the “green carbon” conserved in other forests above water), but the science of measuring and accounting for blue carbon is as yet underdeveloped. Unfortunately, a fifth of the world’s mangroves have been lost since 1980 and they continue to disappear. (Spalding, MD, M Kainuma, and L Collins. 2010. World Atlas of Mangroves. Earthscan, with International Society for Mangrove Ecosystems. Food and Agriculture Organization of the United Nations, UNEP World Conservation Monitoring Centre, United Nations Scientific and Cultural Organisation, United Nations University, London, UK.)
Our guide was sure to emphasize the many other benefits of the mangals as well, including creating habitat for diverse species and therefore enabling the livelihood of fishing communities along the coast. They also provide an important buffer against the rising tides and intensified storms related to climate change.
All of this, of course, was lost to our children who were huddled under the awning of our boat watching another tourist child (from Tabasco) play a game on his mother’s iPhone. They just wanted to know when we were going to the beach and if we could get coca-colas when we got there.
So we left the merciful shade of the beneficial mangal and boarded the boat to head back to the dock and then the beach. There was a palapa with our name on it, where we could sip on cokes, sample merengues, and contemplate the beauty of Celestún. It was the weekend, after all.
Jes Ellis is a teacher at Two Rivers Public Charter School in Washington, DC. This post is adapted from Planet Change, and is part of a series of blogs authored by Jes & Peter Ellis, a Forest Carbon Scientist for The Nature Conservancy. Opinions expressed here are the personal opinions of the author and do not necessarily reflect the views of The Nature Conservancy.
Photos courtesy of Jes & Peter Ellis