Where do sea turtles nest?

From an article by Wendy Dow and Karen Eckert on the State of the World's Sea Turtles:

In a recent assessment, the Wider Caribbean Sea Turtle Conserva­tion Network (WIDECAST) answered the question definitively. Current nesting grounds for six sea turtle species, including 592 sites for the green turtle (shown here), were georeferenced and mapped in collaboration with The Nature Conservancy, the United Nations Environment Programme–Caribbean Environment Programme, the Pegasus Foundation, the U.S. Fish and Wildlife Service, and more than 100 data contributors in the Caribbean region.

The study concludes that Caribbean green turtles typically nest in small colonies. More than half of all known nesting beaches receive fewer than 25 crawls (including successful and unsuccessful nesting attempts) each year. At 141 sites (23.8 percent of the total sites), current data are insufficient to estimate annual crawl abundance, although these colonies are also likely to be very small.

The 32 beaches (5.4 percent of total beaches) reporting more than 500 crawls per year are mostly distributed along the continental margins of the wider Caribbean region. Tortuguero, Costa Rica, recorded more than 50,000 crawls in the 2005 nesting season—by far the region’s largest green turtle nesting colony.