The refuge was designated to protect habitat for what is the most significant area for loggerhead sea turtle nesting in the Western Hemisphere, and the most significant area for green turtle nesting in North America. This represents 25-35% of all loggerhead and green sea turtle nests in the US. It also serves as a minor nesting area for the leatherback turtle, which is one of the world's largest and rarest sea turtles. The long stretches of quiet, undisturbed sandy beaches, with little or no artificial light, are essential to the reproductive success and survival of the 15,000 to 30,000 sea turtles nests laid annually.
Check out the Sea turtle nest update page.

More than 140 species of birds have been documented on the refuge. The refuge is a stopover point for migratory birds, including neotropical passerines. The many aquatic habitats support a variety of water birds, wading birds, shorebirds, and waterfowl. In addition, several raptors are found on the refuge or use it during their annual migrations.

A variety of fish species are found in waters in or near the refuge, and over 350 species utilize the Indian River Lagoon during all or part of their life history (Gilmore 1995). Over 200 fish species are known to occur on or adjacent to the refuge and partner lands, including a federally endangered fish species.

Major refuge habitats are natural habitat types that are generally found on refuge and partner lands. They consist of beach and dunes, surf zones, coastal strand and scrub, shrub and brushland, coastal strand, maritime hammock, cabbage palm hammock, mixed wetland hardwood, mangroves, shrub wetlands, salt water marshes, estuaries (Indian River Lagoon), reservoirs and retention ponds.

Mammal on the refuge include over 15 terrestrial and marine species. The Southern Beach Mouse was historically found on sand dunes on the Carr Refuge.

At least nine amphibians have been identified on the refuge and/or partner lands. Reptile diversity is high on and near the refuge, with at least 35 species of snakes, lizards, turtles and two crocodilians. The gopher tortoise is one species of concern that lives on the refuge.

Marine and estuarine invertebrate species that inhabit tidal areas and deeper waters surrounding the refuge number in the thousands. Prominent groups include squid, crabs, shrimp, clams, oysters, seaslugs, gastropods, worms, and jellyfish. Several invertebrate species have been identified as Species of Greatest Conservation Need for these habitats in Florida’s State Wildlife Action Plan (FCWCS).