The Delta del Orinoco Biosphere Reserve and National Park are characterized by great biological diversity. The Orinoco delta includes large areas of permanent wetlands as well as seasonally flooded freshwater swamp forests which provide habitat for a number of endangered and endemic species.
The Delta del Orinoco Biosphere Reserve encompasses 1,125,000 ha (2,780,000 acres) including the protected areas, the buffer and transition areas, which represents about 31% of Delta Amacuro State total surface.
The Delta del Orinoco National Park (also known as Mariusa National Park) was created in 1991 and offers protection with increasing levels of enforcement. This national park is given IUCN Category II status and covers an area of 331,000 ha (818,000 acres).
The Orinoco Delta Swamp Forests as well as the Orinoco Wetlands (flooded grassland) occur in a diverse and porous matrix of coastal vegetation types along the river delta and surrounding regions of northwestern Venezuela and northeastern Guyana. These inundated forests and flooded grasslands have moderate species richness and provide habitat to a number of endangered and endemic species such as the Orinoco crocodile, Amazon river dolphin, jaguar, bush dog, giant river otter, Orinoco goose, and the harpy eagle.
A great biological diversity characterizes the terrestrial and aquatic ecosystems of the Orinoco Delta. The delta includes large areas of permanent wetlands as well as seasonally flooded freshwater swamp forests. Main habitat types include mangrove forest along with swamp grasslands, shrubs, palms and scrubs.
These ecosystems comprise a variable vegetation with more than 2,000 plants and a very rich terrestrial and aquatic fauna integrated for more than 151 mammals species, 464 bird species, 76 reptiles, 39 amphibians and 210 ichthyology species. Considerable amounts of terrestrial and aquatic invertebrates inhabit this territory.
Much of this region is still intact due to its inaccessibility and poor soils, however recently oil exploration and extraction projects have encroached into these once pristine forests.