Martin County's beaches on Hutchinson Island are some of the most important nesting grounds in North America for the threatened loggerhead and endangered leatherback sea turtles. In 2017, Martin County beaches had the third highest number of loggerhead and leatherback nests in Florida.
The Indian River Lagoon is one of the most biodiverse estuaries in North America. IRL is home to over 400 species of plants and over 1700 species of animals, with about 50 of these species threatened or endangered.