Leatherback research in Florida.

Our research

Leatherback sea turtles (Dermochelys coriacea) are an endangered species. They are the largest species of sea turtle, often reaching over 1,000 pounds. They are very vulnerable to fisheries bycatch, marine pollution and coastal development. Here in Florida, their nest counts and the number of individual nesting turtles are increasing.

We conduct an intensive night-time study utilizing mark-recapture, satellite tracking, and genetic studies to unravel the mystery of the leatherback sea turtle. By tagging individual turtles and documenting every encounter, we can better understand the size and health of the population as well as basic parameters like nest frequency, individual size, migratory patterns, and survival rates.

About leatherbacks

Leatherbacks are the largest living turtle and the most widely distributed reptile on Earth, found in every ocean from tropical nesting beaches to the cold foraging grounds of Newfoundland and Labrador. Unlike any other sea turtle, they have no true bony shell: a mosaic of tiny ossicles lies embedded in a thick layer of fibrous tissue beneath their leathery skin, which gives them their name. Their lineage is ancient, dating back to the Cretaceous, when giants like Archelon swam the seas alongside them.

Leatherbacks are also gigantotherms: their large body size, low metabolic rates, and layer of insulating fat allow them to maintain a body temperature up to 18 °C warmer than the cold waters they often forage in, a trait unusual among reptiles. Their specialized interlocking jaws are built for one purpose: consuming gelatinous prey like jellyfish, their primary food. The species is classified as Endangered in Florida under the US Endangered Species Act and Vulnerable globally by the IUCN.

Leatherbacks in Florida

The first leatherback nest in Florida was recorded in 1947, and for decades afterward Florida was considered a minor nesting site. That has changed dramatically. Since standardized counts began in 1979, Florida’s leatherback nest numbers have increased by 10.2% per year^[1] — one of the strongest leatherback recovery signals in the Atlantic basin.

Today, roughly 200 kilometers of contiguous Atlantic coastline across Palm Beach, Martin, and St. Lucie counties hosts the overwhelming majority of Florida’s leatherback nesting, and Martin County hosts the highest density of leatherback nesting in the state^[2]. From 2001 to 2011, our team ran an 11-year mark-recapture study on a 19.4 km segment of northern Palm Beach County between Jupiter Inlet and Lake Worth Inlet — the Juno Beach study area. We estimated an average nesting population of 100 ± 41 females per season at Juno, with 88.9% annual survival and a remigration interval of 2.7 ± 1.0 years^[1]; the statewide population is necessarily larger. Unlike hard-shelled sea turtles, leatherbacks are remarkably flexible in their nest-site selection — individual females have been documented laying clutches up to 463.5 kilometers apart within a single season^[1]. After nesting, Florida females travel north to forage along the southeast US continental shelf, with some ranging as far as the waters off New England and Atlantic Canada.

How we conduct this study

From mid-March through late June each year, our team patrols a 35-kilometer stretch of beach in Martin County, Florida — from Jupiter Island to the St. Lucie county line — searching for nesting leatherbacks each night from sunset until early morning. Every turtle we encounter is identified, either by tags applied in previous seasons or with a new set of three unique identifiers: two metal flipper tags and a microchip injected into the right shoulder. Each individual is measured, examined for distinguishing marks or injuries, and recorded.

All work is conducted under Marine Turtle Permit #208, issued by the Florida Fish and Wildlife Conservation Commission, in collaboration with scientists at the Sea Turtle Conservancy, National Marine Fisheries Service, Ecological Associates Inc, Florida Fish and Wildlife, WIDECAST, and academic research institutions.