The coastal lagoons of Oaxaca are hidden treasures. Many people drive along the coast highway with no destinations in mind other than towns or beaches. But in fact some fascinating lagoons lie a relatively short distance off the main road.
Two large lagoons not far from Huatulco are very accessible. Manialtepec Lagoon is located north of Puerto Escondido, and La Ventanilla is slightly north of Puerto Angel. In addition, the Lagunas de Chacahua (a national park) are relatively close to Puerto Escondido but cannot be accessed without taking a boat ride.
These lagoons are frequented by birders, biologists, and savvy tourists in addition to indigenous people. Lagoons around the world are remarkable for the biodiversity of the habitat, which provides shelter and sustenance to an enormous variety of animal species and rare plants. As coastal lagoons are gradually disappearing, it is worthwhile taking the opportunity now to experience ones that are close. The current enthusiasts for lagoons would probably be glad to keep these treasures hidden, but the more people who recognize the value of lagoons and delight in what they offer, the larger will be the constituency for protecting them.
If you visit during daytime, the beauty of the lagoons, even from a distance, is breath-taking. Since the lagoons are fed by both fresh water rivers and streams of water flowing from mountains and ocean tides, the mineral content of the water varies within the same lagoon and between them. This variation produces remarkable changes in color as your boat moves from place to place, or if you raise your eyes you will see a roiling kaleidoscope of colors from deep blue to green to grey and brown.
The islands in lagoons appear to float above the water, because the trees that adapt to living in a lagoon magically begin above the surface and appear to be walking on the water. The primary trees are mangroves, which are adapted to saline conditions, at times, even more intense than sea water. Red mangroves ring the islands, standing on long exposed salt-resistant roots. Black and white mangroves and button willows spread out in the interiors of the islands, protected by their red cousins. None of these plants are seen outside tropical latitudes. The mangroves not only bind the soil in place against tidal action, they actually make soil by capturing sediment that is flowing past. They provide a fertile environment for other trees and plants including coconut, spaghetti algae and widgeon grass. In the shallower parts of the lagoons, water lilies show off their beautiful flowers that you may have only seen previously in the most opulent paintings of Monet.
Under the surface, the roots of the mangroves provide a sanctuary and nursery for a rich collection of sea life-from microorganisms to invertebrate larvae, to oysters, crabs, and baby fish. Swimming in and out of the mangrove roots are sea bass, catfish, and other finny friends.
The mangroves harbor a rich soup of delicacies that attract hundreds of different types of birds. Some of the birds that you will see in lagoons are actually common on the Oaxacan coast; these include pelicans, herons, ibis and egrets. Still, you are unlikely to experience the thrilling sight of a tree full of pelicans elsewhere. Birders are attracted to lagoon areas because of the presence of more elusive species such as the roseate spoonbill and the white fronted parrot. Birders who keep meticulous records of their sightings can check off over 350 different species of birds.
But visitors to lagoons, beware! Lurking in wait for a tasty avian or fish dinner are crocodiles. The “log” floating in the water near the mangroves can turn into a huge mouth full of nasty teeth. Although the crocs have plenty of nonhuman food to keep their bellies full, it’s best not to trail your hands or feet in the water while gliding through the lagoons. Other reptilian cousins found among the mangroves include iguanas, lizards and snakes. But they are less intrepid than their toothy relatives, and glimpses are rare.
Humans are only one species of mammals attracted to the lagoons. Deer can commonly be seen on the lagoon shores, even though they are shy. Tiny rodents provide a draw for carnivores such as bobcats and omnivorous racoons.
By night, the predatory mammals become more active. If you take a moonlit trip through a lagoon, it can be quite an auditory adventure. The hoots of owls, the rustle of the mammalian hunters, and the sound of waves on the beaches at the end of the lagoons provide a nocturnal chorus.
We are fortunate to have available to us a magnificent night-time lagoon experience at the Manialtepec lagoon. It cannot be guaranteed at every visit because it is dependent on the temperature and currents of the ocean and the light conditions. Given the right circumstances, millions of phosphorescent dinoflagellates are washed into Manialtepec lagoon, turning the waters luminescent. Tiny points of light float lazily around you under the surface of the water. On clear moonless nights, it seems as if millions of stars above have been reflected in the waters below. Moreover, every large object in the water, especially if it is moving, will be outlined in a hauntingly brilliant silver-blue aura. Your boat driver will invite you to swim in these dark but glowing waters. If you do, and see your body invisible but your outline ablaze, you will have an indelible memory that cannot easily be duplicated anywhere on earth.
Why are the lagoons gradually vanishing? It is sad to realize that we humans are destroying lagoons. Some are being destroyed by draining the waters and removing the mangroves to build hotels. Most are perishing by slowly being poisoned by agricultural toxic fertilizer that washes into the rivers that feed the lagoons. And even human visitors who carelessly toss trash into the lagoons speed up the deterioration.
If this article has stimulated you to want to see the lagoons, you’ll have to take some initiative to do so. We’re not going to provide the standard information about locations of entrances to these attractions, available services, and hours of operation. If you are interested in experiencing and protecting this precious habitat, we hope you will make the effort to enjoy the lagoons by day or night.