Within its limits, the property encompasses a unique system of lagoons, mangroves, inundated forests, lowland forests, and karstic mountain forests between sea level and 385m, which together harbor a high level of biodiversity. Because of its unique wetlands, Río Sarstún is registered as a RAMSAR Site. Its floral diversity includes important wetland and rainforest trees such as Palo Maria (Calophyllum brasiliense), Yemeri Loca (Vochysia hondurensis), Cabbage Tree (Andira inermis), Grandadillo (Platymiscium dimorphandrum) (“Hormigo”), Shaving Brush Tree (Bombax ellipticum), Rosewood (Dalbergia tucurensis), Virola koschny, Pouteria amygdalina, Guayacan (Sweetia panamensis), Coco Plum (Chrysobalanus icaco), Deer Tongue (Hirtella paniculata), and Amarillón (Terminalia amazonia). Four mangrove species can be found in the area: Black Mangrove (Avicennia germinans), White Mangrove (Laguncularia racemosa), American Mangrove (Rhizophora mangle) and Silver-leaved Buttonwood (Conocarpus erectus), the last two included in the red list of endangered species of CONAP (National Council of Protected Areas). One of the most notable plant communities are “Dwarf mangroves”, which are unique in the country and restricted to areas with a combination of karstic soils and high salt concentrations.
Sea grasses like Turtle Grass (Thalassia testudinum) and Manatee Grass (Syringodium filiforme) are contained within the aquatic ecosystem, providing food to a variety of fish species and the threatened West Indian Manatee (Trichechus manatus) (VU), which is protected on the Appendix 1 of CITES and in the Red List of CONAP. Some of the fishes that can be found are Horseface Cichlid (Cichlasoma aureum), Blind Cave Fish (Astyanax fasciatus) and Tarpon (Megalopus atlanticus); all three have commercial value and are listed as endangered by CONAP.
At least 52 species of mammals are found in the Sarstun Protected Area, and many of them have been reported within the Laguna Grande property, including the West Indian Manatee. Other threatened species including: Jaguar (Panthera onca) (NT), Baird’s Tapir (Tapirus bairdii) (EN) and Yucatán Black Howler Monkey (Alouatta pigra) (EN). The Río Sarstún region is particularly important for its bat diversity: more than 30 species were recorded at one site to the south of the Laguna Grande property, one of the highest counts in Latin America (45 species in Pantanal, Brazil). The area is also a vital habitat for endangered Neotropical migratory birds, many of which are endangered and suffering population declines. The Caribbean Forests of Guatemala are visited during the Northern Hemisphere winter by over a 100 species of migratory birds, of which 19 species have population declines in North America. Data suggest that habitat loss and degradation in wintering habitats is causing diminished survivorship and/or physical condition of these species. Habitat conservation in the Caribbean region of Guatemala is therefore vital in order to tackle population declines of these Neotropical migratory birds.