EGLIN AFB — Biologists have documented nests of four different species of sea turtle — two of them rare — on Eglin beaches, marking the first time these species have been on the Air Force base's beaches together.

The four species include loggerhead and green sea turtles, both considered threatened, and leatherback and Kemp's ridley sea turtles, both considered endangered, according to Kathy Gault, an Eglin Air Force Base biologist.

"It's a great feeling," Gault said. "If one of our patrollers calls us to go see a Kemp's or a leatherback, all of us are down there, and we get as many people down there to see it as possible.

"Everybody gets really excited about it, and it really is a cool thing."

The Kemp's ridley nests are the rarest on Eglin beaches, according to Gault. Eglin discovers one, or maybe two, Kemp's ridley nests each year.

"Historically, they were primarily nesting in Mexico," Gault said.

Several years ago, Gault said, the Kemp's ridley turtles were reintroduced in Texas to insure the turtles hatch, and they have since expanded into the Panhandle.

Kemp's ridley turtles are the smallest marine turtles in the world. Kemp's ridley turtles are one of two species that participate in "arribada" nesting, where the females gather in large groups and come onto the beach to nest all at once to insure safety from predators, according to the U.S. Fish and Wildlife Service's website.

Kemp's ridley turtles are considered endangered by the FWS with by-catch, or accidental capture in fishing gear listed as the primary threat, along with egg harvesting and ocean pollution.

The leatherbacks are also rare to this area. They are found mostly on the east coast of Florida in the Atlantic Ocean, Gault said.

"We had three in 2000, one in 2012, and one this year," she said.

According to the FWS, leatherbacks are the largest turtles on Earth, weighing up to 2,000 pounds and growing to nearly seven feet long. These turtles can dive deeper than any other turtle, to depths of over 4,000 feet, and can stay underwater for up to 85 minutes.

The leatherback population is declining, with Pacific leatherbacks nearing extinction. Like many sea turtle species, the primary threat to leatherbacks is by-catch in fishing gear, according to the FWS. The status of each sea turtle species is based on the population size and the risk of going exist in the next 25 years, Gault said.

Listed as threatened by the FWS, loggerheads are the most common on Eglin beaches and nest every two to three years. Green sea turtles are the second most common and typically only nest every other year statewide, Gault said.

The average number of nests varies each year, Gault said. 

"We had a low of 11 nests in 2010, the year of the oil spill, and a high of 77 nests in 2017," she said. "Lately, we've been getting around 60 nests on Eglin."

On average, more than 3,000 turtle hatchlings make it into the Gulf of Mexico from Eglin beaches each year.

During nesting season, Gault said, a few things are important for beach residents and visitors to remember: Always use red rather than white flashlights, keep blinds closed at night, and fill in holes after a beach day.

"We actually had a female turtle come up on our public beach between Destin and Fort Walton, and she came up and nested," Gault said. "But on her way back to the water, she oriented the wrong way for about 800 feet, which for a turtle that weighed 200 to 300 pounds is a long way to go on land."

Gault said some turtles have become so disoriented on Eglin beaches that they've headed for U.S. Highway 98.

The Eglin reservation is patrolled by volunteers with Eglin AFB Natural Resources, a program overseen by Gault along with three other contractors. Permitted by the Florida Fish and Wildlife Conservation Commission, Gault said, two people patrol 17 miles of beach each day.