Sierra A Mar works to conserve the river crocodile.

Did you know that crocodiles are essential species for the balance of coastal ecosystems?

Their role as apex predators is to regulate the populations of other smaller species and help the circulation of nutrients. Crocodiles are also expert builders of nests and channels, creating habitat for fish, amphibians, and birds while maintaining the hydrological connectivity of coastal lagoons and mangroves.

In Jalisco, one of the most important freshwater sites for the river or American crocodile (Crocodylus acutus) is the Majagua Reservoir, located near La Huerta in the Costalegre region. This reservoir, originally built for irrigation, has become a refuge for diverse wildlife, including a stable population of crocodiles. The combination of calm waters, abundant fish, and surrounding vegetation provides ideal conditions for nesting and basking. Studies by local environmental groups have identified Majagua as a strategic area for monitoring crocodile populations, particularly because it links inland wetlands with nearby estuaries and mangroves along the Pacific coast.

The river crocodile is the only species present in the Costalegre–Jalisco area, of the three that exist in Mexico. Its conservation is a priority for the national government and protected areas across the country’s coastal zones. Initiatives in Majagua include community-led surveillance, habitat restoration, and educational tours to promote coexistence between people and crocodiles. Protecting this reservoir not only benefits crocodiles but also ensures water quality and biodiversity for surrounding communities.

August 23 marked National Crocodile Day, which coincides with the birthday of Miguel Álvarez del Toro, a renowned scientist who dedicated his life to the study and conservation of Mexican reptiles.

At Sierra a Mar, we encourage and support communities seeking to promote crocodile conservation initiatives particularly in the Chalacatepec lagoon. Our work is based on understanding the interactions between humans and crocodiles and proposing conservation strategies through research and participatory planning — whether in coastal lagoons, mangroves, or key inland habitats like the Majagua Reservoir.