The geology beneath Morrocoy is ancient reef. The Chichiriviche hills, rising to 285 meters at their highest point, sit on the Capadare-Agua Linda limestone formation, a structure of Tertiary-period coral origin. The park's cays and coastline are built from the skeletons of organisms that lived millions of years before the first mangrove seed floated into these shallows. Today, four species of mangrove - red, black, white, and buttonwood - dominate the landscape, covering roughly 4,500 hectares. They form the ecological lungs of the park, stabilizing the fragile coastline, filtering sediment, and sheltering juvenile fish and crustaceans in their submerged root systems. Underwater, seagrass meadows provide food for green sea turtles, while the coral reefs - though diminished by human activity in recent years - still support grouper, snapper, barracuda, and spiny lobsters.

The mangrove-covered island of Pájaros sits in the central area of the park and functions as a bird sanctuary. Some 266 species have been recorded across the wider Morrocoy-Cuare region, a count derived partly from the adjacent Cuare Wildlife Refuge. Scarlet ibises roost in vivid red clusters against the green mangroves - one of those sights that looks improbable even when you are watching it happen. American flamingos, brown pelicans, and tricolored herons are listed as vulnerable species here. Ospreys hunt the shallows. Scaled piculets, orange-winged amazons, and neotropic cormorants favor the mangrove habitat. Magnificent frigatebirds, with their two-meter wingspans, patrol the outer cays. BirdLife International has designated Morrocoy an Important Bird Area for its significant populations across multiple species.

The waters around Morrocoy shelter species that are running out of places to hide. Green, hawksbill, leatherback, and olive ridley sea turtles all use the park, and all are considered threatened. American crocodiles inhabit the quieter mangrove channels. Dolphins and whales pass through the offshore waters, using the park as a seasonal refuge. On the Chichiriviche hills, the land fauna is surprisingly diverse: brocket deer and white-tailed deer, howler monkeys, three-toed sloths, crab-eating foxes, peccaries, pacas, agoutis, and anteaters. The reef systems host a catalog of commercially important fish - tarpon, snook, mackerel, sardines, corvina - alongside mangrove oysters, sea hares, and both species of Caribbean spiny lobster. The park's biodiversity is a measure of what coastal ecosystems can sustain when they are given protection, and a warning of what they lose when that protection falters.

Morrocoy's beaches read like a Caribbean postcard catalog: Sombrero Cay, Playuela, Playuelita, Alemán Cay, Mayorquina, Pescadores Cay, Mero Beach, Boca Seca, Los Juanes. Some are reached by road from the towns of Tucacas or Chichiriviche; others require a boat, which keeps them quieter. Los Juanes, accessible only by sea via private or fishing boat, offers two small islands ideal for snorkeling over coral reefs and through mangrove channels. Three islets beyond the park boundary - Norte, Medio, and Sur Cay, about 13 kilometers from Tucacas - sit in a Special Protection Area. The climate cooperates: trade winds keep temperatures between 27 and 35 degrees Celsius year-round, and the driest months offer warm water and visibility good enough to make the reef's remaining corals shimmer.