The marine life is exceptionally abundant, particularly with sharks, notably the hammerhead, which can reach four meters in length, and the white-tipped shark. Also widely found are parrot fish, tuna and mantas. The most numerous plant species are the cupey, the endemic Euterpe macrospadix palm and huriki. Ferns, bromeliads and selaginellas are also very abundant. The three endemic bird species are the Coco Island cuckoo.
Sea birds are particularly abundant, especially on the nearby islets.
This national park is made up of a mosaic of diverse of limestone hills. The Palo Verde area is subject to seasonal floods of great magnitude due to its clack of natural drainage. This produces a greater ecological diversity-between 12 and 15 habitats have been identified. These habitats include salt and fresh water lakes and swamps, grasslands with black mangroves, mangrove swamps, pastures, lowland stunted forests, wooded savannas and evergreen forests. The hills area home to an endemic species of cactus.