The island and its environs invite study from several points of view. It is Costa Rica's largest concentration of coral-building organisms along the Pacific. Boring sponges, Diadema sea urchins, sea cucumbers, many crustaceans and calcareous alga mats and balls add to the variety of life found among the Porites and Pocillopora corals of these reefs. Recolonization and regrowth of the corals is being studied intensively. Marine life is abundant in the general vicinity of the island.
Fishing boats take tuna, shrimp, shark, mackerel, snapper, and sardines in quantity.
Manta rays are often seen breaching. Humpback whales are seasonally present and often sighted from Punta Marenco, and killer whales have been reported near the Isla Violines and mouth of the Sierpe River . The island's forest and its inhabitants are in starck contrast to those on the mainland less than 11 miles away. The island has a resident insect fauna that is perhaps one percent as rich as that of the mainland. Moreover, the forest on this island is a curiously impoverished version of that on the mainland.