Each passenger will receive a checklist of the 300 species of birds found in the region. We usually view 50 to 70 species of birds on each trip, depending on your skills. Few mammals are observed as they are primarily nocturnal. However, on previous trips we have observed tropical otter and jaguarundi (both endangered species), anteater, opossum, coatimundi, crocodiles, boas, and iguana species. On our beach break we have observed dolphins, whales, sharks, manta rays, sea turtles and their nests. We often pull up alongside fishing boats to watch them hauling in their nets and see the fish and seafood they are catching. While biting insects are rarely a problem, bring along your insect repellent if you have some. We’ll also have some onboard just in case it’s needed.
The biodiversity of Manialtepec Lagoon is so rich due to the convergence of 3 very different aquatic ecosystems - 1) the Brackish (partly salty) Deepwater Lagoon itself. 2) the Manialtepec River descending from the Sierra Madre del Sur Mountains, pouring into the lagoon and 3) the Pacific Ocean Coast. All 3 ecosystems host unique flora and fauna. Manialtepec is a dynamic lagoon ecosystem with the freshwater river entering its northwest end. Lagoon salinity is highly variable throughout the year depending on the barrier beach containing the lagoon being open or closed. For 6 months during the rainy season beginning in June a huge volume of fresh water blasts down the mountain side and pours into the ocean via the lagoon. The strong river flow keeps the barrier beach open for approx 6 months and the lagoon rises and falls with the ocean tides. Fish, shrimp, and shellfish enter from the ocean to spawn in the lagoon. With the end of the rainy season in November the pounding surf of the Oaxaca coast overcomes the diminishing river flow and tosses up a barrier beach of sand. The lagoon now becomes separated from the ocean for 6 months. The slower flowing river is redirected by this dam of sand and slowly begins to fill the lagoon basin, with the lagoon rising approximately 5 feet vertically. The 5 foot vertical rise translates into a horizontal flood of up to1 kilometer around parts of the lagoon. It is this ever-changing flood zone where a rich mangrove forest develops - mangrove being a unique group of tree species that can tolerate salt water. Mangrove forest lagoons accumulate nutrients delivered by both mountain rivers and the sea, and thus they can support a wealth of fish and shellfish, that in turn attract birds, wildlife and mankind. Because mangrove forests are one of the most productive habitats on our planet they are highly biodiverse and fascinating. We invite you to explore this incredible ecosystem, up close and personal, with a professional guide.
Hidden Voyages Ecotours actively supports and designs conservation projects on Manialtepec Lagoon. We have sponsored university research programs, assisted with bird banding studies, children’s school programs, have sponsored birding courses for and donated books and binoculars to local birding guides, donated to a sewage treatment project at our dock restaurant, and have assisted with trash collection on the lagoon. We will continue to support lagoon dwellers with lagoon conservation and education programs. Your help to protect this threatened lagoon is very much appreciated.
Hidden Voyages Ecotours is proud to have sponsored a field course for new birding guides from the coast of Oaxaca including La Barra de Colotepec, Pto Escondido, Manialtepec Lagoon, and Zapotalito at Chacahua. They were given at no charge waterproof binoculars, field guide books of the Birds of Mexico, guide books for the northern migratory birds along with class and outdoor field experience. It is my belief that only by having the locals involved and prospering from ecotourism activities that they will become actively involved in conservation of the unique lagoons and wildlife of this beautiful wild coast. Michael Malone photo.