Wildlife Watching in America's National Parks: A Seasonal Guide

4. June—Sea Turtles of the Dry Tortugas

73| 4 { June Sea Turtles of the Dry Tortugas There are few experiences as serene, as calm, and—somewhat paradoxically —as exhilarating as being underwater and watching a sea turtle effortlessly swimming through a turquoise sea. These animals exemplify peacefulness as they glide through an underwater world we can only visit. Of course, sea turtles are only one of many fascinating and colorful animals that can be found in the world’s oceans. And nowhere are the oceans more alive and colorful than in the coral reef habitats. The healthiest and most colorful coral reefs in the contiguous forty-eight states are those found in Dry Tortugas National Park, an island park far off the Florida Keys. One needs a boat or floatplane to get there, but it's well worth the ride. What’s Remarkable about Sea Turtles? The first sea turtles appeared on earth over 100 million years ago, at a time when the earth was populated with dinosaurs. Somehow these turtles survived the mass extinction event that killed off the dinosaurs and many other species about 65 million years ago. Although it’s easy to say the turtles survived because they were in the oceans, that doesn’t fully explain their persistence; many ocean “dinosaurs” such as plesiosaurs (not technically dinosaurs, but often lumped with them) and other sea creatures became extinct. In fact, it’s been estimated that three-quarters of the species identified in the fossil record disappeared during that cataclysmic 74 | Summer period (perhaps due to a massive meteorite hitting the earth). So how did a slow-moving, nonaggressive, cold-blooded animal manage to survive when so many others perished? It’s a mystery that may never be solved, but what is known is that sea turtles are remarkable creatures. Sea Turtle Species There are five species of sea turtle in the Atlantic Ocean. The loggerhead and green sea turtles are the principle nesters along the beaches of the southeastern united States, with the loggerhead by far the most abundant (although that’s a comparative description as they too are a threatened species). However, divers and snorkelers most frequently observe green sea turtles due to their strong fidelity to shallow coastal waters such as those at Dry Tortugas National Park. loggerhead sea turtles loggerheads are the most commonly observed nesting sea turtle, comprising 90 percent of the egg layers on Florida beaches. every couple of Watching a sea turtle swim is almost surreal. At Dry Tortugas all one needs to see these creatures is a swim mask and snorkel. (Photo by Daniel S. Licht) 75| June–Sea Turtles of the Dry Tortugas Against all odds Seeing a sea turtle in its natural environment is an unforgettable moment as you watch the animal swim with ease through its underwater environment. It seems to have such a trouble-free life, but think about this. That sea turtle is one in a thousand. When it hatched many years prior it was just one hatchling among many in that nest, and that nest was one of many on that beach, and that beach was one of many beaches. That turtle you are looking at made it to adulthood, either through luck, skill, or most likely, a combination of both. Meanwhile, 999 other hatchlings didn’t survive. Some never got out of the egg, some never made it out of the nest, some never survived the journey down to the water’s edge, some perished shortly after entering the ocean, and many others died as juveniles while out in the vast ocean. years egg-bearing females migrate to their natal beaches where they laboriously crawl up the beach, excavate a 20-inch-deep hole in the sand, and lay their fifty to two hundred eggs. About two months later, usually under the cover of darkness, the eggs hatch and the young dig their way out of the sand and make their perilous journey down the beach and into the sea. The lucky ones that make it to the ocean adopt a drifting lifestyle at the mercy of the currents. The young turtles feed on tiny marine animals found in the wandering rafts of seaweed. Once the turtles reach the size of a dinner plate they feed mostly on shellfish. eventually, the turtles will mate and the females will make their epic journey to the same sandy beaches where they were born to continue the circle of life...