El Gancho-Murillo

El Gancho-Murillo is a state ecological conservation zone in Chiapas, Mexico, protecting a coastal mangrove and wetland ecosystem in the Soconusco region near Tapachula, along Mexico's Pacific coast. ^[1] The reserve encompasses mangrove forests, lagoons, freshwater marshes, and transitional vegetation in the municipalities of Suchiate and Tapachula, close to the Guatemala border. ^[1] Designated a Ramsar Wetland of International Importance (site #1772) on February 2, 2008, the reserve protects critical habitat for migratory waterbirds using the Pacific Flyway, nesting sea turtles, and commercially important fish and shellfish populations. El Gancho-Murillo is closely linked ecologically with La Encrucijada Biosphere Reserve to the northwest, together forming part of a larger coastal wetland complex in southern Chiapas.

The wildlife of El Gancho-Murillo reflects its position as a coastal mangrove wetland and transitional ecosystem. Species recorded include the spectacled caiman (Caiman crocodylus fuscus), olive ridley sea turtle (Lepidochelys olivacea, endangered), margay (Leopardus wiedii), and ocelot (Felis pardalis)—all listed under Mexican wildlife protection laws. ^[1] Resident birds include belted kingfishers, green kingfishers, boat-billed herons, bare-throated tiger herons, and various egrets that exploit the river margins and mangrove channels. Migratory waterbirds including shorebirds and waterfowl pass through during the October–April period. Freshwater turtles, coatis, and raccoons also inhabit the area. The mangrove lagoons and estuarine channels provide essential nursery habitat for commercial fish and shrimp species. The riparian and mangrove habitat supports a diverse bird community including warblers, vireos, and tanagers during migration.

The dominant vegetation of El Gancho-Murillo is mangrove forest, comprising a compact surface of red mangrove (Rhizophora mangle) and white mangrove (Laguncularia racemosa) as the dominant species, along with other mangrove associates. ^[1] Cattail marshes, palm forests, and tropical deciduous forest and secondary vegetation occupy areas in different stages of development. Freshwater marsh communities with bulrush and water hyacinth occur in the slower, fresher sections of the waterway. Surrounding agricultural lands are dominated by mango orchards, cacao plantations, and seasonal corn and bean fields that have replaced natural vegetation. Management aims to restore native mangrove cover in buffer zones around the protected waterways, with ongoing restoration projects targeting water channel connectivity to improve fisheries. ^[2]

El Gancho-Murillo occupies the lower coastal plain near the Suchiate and Tapachula rivers, which drain the granitic and metamorphic basement rocks of the Sierra Madre de Chiapas. The rivers transport sediment from the mountains and deposit it on the gently sloping coastal plain, building alluvial fans and flood plains reworked over thousands of years. The reserve's flat terrain sits on thick alluvial deposits of sand, gravel, and clay that form productive coastal soils. Near the river channels, levee deposits of coarser sand alternate with fine-grained overbank deposits that support gallery forest and mangrove vegetation. The coastal plain geology is underlain by Tertiary marine sedimentary rocks at depth, buried beneath the alluvium. The entire coastal plain faces subsidence risk due to sediment compaction, which combined with sea level rise increases flood risk in low-lying areas.

The climate of El Gancho-Murillo is warm and seasonally dry, typical of the Chiapas Pacific piedmont and coastal plain. Annual temperatures average 26 to 30°C, with little seasonal variation in temperature but pronounced variation in rainfall. The rainy season from May through October brings significant precipitation, causing rivers to rise significantly and inundate floodplain areas. The dry season from November through April is markedly arid, with rivers receding and marshes contracting. Tropical storms and hurricanes from the Pacific can impact the region from June through October, bringing extreme rainfall events that cause flooding. The pronounced dry season concentrates wildlife near permanent water sources and the mangrove lagoons, making this the best period for wildlife observation.

The coastal plain and piedmont of Chiapas have been inhabited continuously since pre-Columbian times, with Mixe-Zoquean and later Maya populations farming the fertile alluvial soils and exploiting the coastal fisheries and mangroves. Spanish colonialism transformed the landscape through cattle ranching and the establishment of large haciendas. The Pacific coast developed a sugar economy in the colonial period, and later cacao and coffee cultivation expanded on the higher slopes. The coastal and estuarine fisheries within El Gancho-Murillo have historically provided subsistence food including fish and artisanal shrimp to local communities. Land reform in the twentieth century redistributed some hacienda land to ejido communities, which continue to farm and fish adjacent to the reserve today.

El Gancho-Murillo was designated a state ecological conservation zone by the Chiapas government to protect mangrove and coastal wetland habitats facing progressive degradation on the Pacific coastal plain. The designation came as part of Chiapas's effort to complement federal protected areas with a state-level network. The reserve received international recognition as Ramsar Wetland of International Importance (site #1772) on February 2, 2008, acknowledging its significance for waterbird populations and coastal ecosystem services. ^[1] Management responsibility falls under the Chiapas state environmental authority, which has worked with local municipalities and ejido communities on developing compatible land-use plans. Conservation efforts have included mangrove restoration initiatives to improve food security and fisheries productivity for neighboring communities. ^[2]

El Gancho-Murillo is primarily visited by naturalists and birdwatchers interested in the mangrove and wetland wildlife of the Chiapas Pacific coast. The lagoon and mangrove channels can be explored by small boat or kayak, offering close-range observation of wildlife resting on banks, kingfishers hunting from overhanging branches, and herons stalking the shallows. The dry season from November through April provides the best conditions for wildlife observation when animals concentrate near water. Local community guides can be arranged through the nearest towns for navigation through the waterway system. No formal visitor center or established trail network exists within the conservation zone. The reserve is accessible via roads from the coastal highway system (Mexico Federal Highway 200) connecting Tapachula with the Guatemala border, near the town of Tapachula. ^[1]

Access to El Gancho-Murillo is via the coastal highway (Mexico Federal Highway 200) that runs along the Chiapas Pacific plain near Tapachula. Tapachula, the main urban center of the Soconusco region, is the nearest service center with hotels, restaurants, and bus connections, approximately 20 kilometers away. Local roads off the coastal highway provide access to communities near the reserve boundary. No formal entrance infrastructure exists; visitors should inquire with local communities or the Chiapas state environmental office for current access arrangements and guide availability. Boat rental from fishing communities near the mangrove lagoons is the primary means of entering the wetland interior. The reserve is best visited in the dry season, and visitors should bring water, sun protection, and insect repellent. The closest airport with commercial service is at Tapachula.

Key conservation challenges at El Gancho-Murillo include controlling conversion of mangrove habitat for agriculture and aquaculture, managing invasive water hyacinth that clogs waterways, and protecting sea turtle nesting beaches. Mangrove restoration is an active conservation strategy in the reserve, with community-based projects clearing obstructed water channels to restore tidal flow and improve fish nursery conditions. ^[1] The Ramsar designation supports international cooperation for monitoring and management funding. ^[2] Climate change projections for the Chiapas Pacific coast suggest increased drought severity during dry seasons and more intense rainfall events, both of which stress the mangrove and wetland ecosystem. Coordination with upstream municipalities on controlling agricultural chemical runoff is important for maintaining water quality within the reserve.