Estero del Yugo

The Estero del Yugo is a small coastal lagoon in the Cerritos area at the northern end of Mazatlán, about 10 minutes beyond the Zona Dorada, where Avenida Sábalo-Cerritos runs past the Mazatlán unit of the Centro de Investigación en Alimentación y Desarrollo (CIAD), a public research center. The estuary covers almost 11 hectares in two lagoons, north and south, split by an earth embankment built in the 1970s; a channel with a sand bar links them to the Pacific and opens only at times through the year, so the tides have little effect. Two streams, El Yugo and the CIAD stream, and some fifteen seasonal runoffs feed it in the rainy season, from June to October.

Around the lagoons, the estero's 358-hectare watershed holds one of the last fragments of native coastal vegetation inside the city: low deciduous dry forest, coastal scrub, mangrove, water lilies, cattail and other marsh plants, and dune vegetation along about 3 km of shoreline with sandy beaches, low cliffs and rocky tide pools. Botanists at CIAD's herbarium have recorded 393 species of flowering plants here between 1996 and 2022, about a tenth of the flora of Sinaloa, including 42 species found only in Mexico and a relict coastal stand of the tree Piranhea mexicana. Nearly half the watershed falls inside a Ramsar wetland site, which in turn links north to the Meseta de Cacaxtla protected area, and since 1997 CIAD has managed the 9.37-hectare federal zone around the lagoons.

Since the 1990s the estero has been open to the public for environmental education, research, recreation and walks on its trails, and it is known in Mazatlán as an urban bird sanctuary: about 200 animal species have been counted, and coastal and migratory birds come to its two lagoons. It has been part of the Mazatlán bird festival, with short, easy guided walks of about four hours. The area is also under heavy pressure from the condominium towers going up around it, and the botanists who studied it have asked for it to be declared a municipal nature reserve.