Sea turtles are among our most precious natural resources. Saltwater reptiles, they are graceful and well adapted to life in our oceans. Their aerodynamic bodies and flipper-like limbs enable sea turtles to cover great distances in the water in comparatively short periods of time. Active sea turtles will swim every few minutes to the oceans’ surface to breathe. During resting periods, the turtles can remain underwater for up to 2 hours without breathing.
Sea turtles once roamed the oceans by the millions but over the past few centuries the demand for sea turtle meat, eggs, shell, leather and oil has greatly reduced their number. Turtle populations will continue to decline because of the trade in sea turtle products and because of the loss of essential habitat. Concern for the plight of sea turtles is growing and around the world, conservationists, governmental agencies, public and private organizations, corporations, and concerned individuals are working to protect sea turtles on nesting beaches and at sea.
Each summer, Florida beaches host the largest gathering of nesting sea turtles in the United States. The adult females emerge from the surf to deposit eggs in sand nests and later, tiny hatchlings struggle from these nests and scramble to the ocean. Nearly all of this activity takes place under cover of darkness.
Even though sea turtles are at home on the oceans, they are inextricably tied to the land too because the adult females must return to land to lay their eggs in a sandy beach. Scientific research has shown that the female turtles return to nest on the same beach where they were born. While the turtles often must swim long distances from their feeding grounds to their nesting beaches, just how they find their way to that nesting beach is still unknown.
From the middle of June till the end of October, eggs buried on the beaches of South Florida will spring hatchlings that dig their way out of the nest and race toward the ocean waters. During nesting season, turtles produce as many as 15,000 nests a year in Palm Beach County. About 1 million turtles emerge, about 50% to 70% of the total eggs laid, but researchers believe only 100 to 1000 survive to sexual maturity.
Did You Know?
- The temperature of the nest determines a hatchling’s gender. Warmer temperatures produce mostly females, and cooler temperatures produce a majority of males.
- Nesting sea turtles return to lay eggs in the same general region where they are hatched.
- Roughly one quarter of all sea turtle nestings in Florida occur in Palm Beach County, making our beaches extremely important to the survival of these threatened and endangered species.
Loggerhead Turtles
The reddish-brown loggerhead turtle is the most common sea turtle found in the southeastern United States. 90 percent of the estimated 14,000 female loggerheads can be encountered in Florida. These turtles, named for their disproportionately large heads, have powerful jaw muscles which enable them to feed on a variety of heavy shelled mollusks and crustaceans in addition to jellyfish. Loggerhead turtles range in size from 33-40 inches shell length and 150-400 pounds. They reach maturity between 20 and 30 years of age and will be able to reproduce over a period of approximately 30 years. Loggerheads nest between late April and October prior to swimming off to feeding grounds throughout the Caribbean, northeast along the U.S. coast to New Jersey, southeast through the Florida Keys, and west to the Gulf of Mexico.
Green Turtles
Green turtles, named for the greenish color of their body fat, are medium to large reptiles. Their shells are distinguished by a mottled or radiating pattern of markings. Green turtles differ from other members of the sea turtle family because of the single pair of scales on the front of their smallish heads. Greens can be between 36 and 43 inches long, weighing between 200 and 300 pounds. Green turtle nesting shows a clear pattern of alternating high and low years. The years 1999 and 2000 give a good indication of this high/low pattern with 479 reported green turtle nests in 1999 and 8,404 green turtle nests reported in Florida in 2000, this according to data collected by the Florida Marine Research Institute. Greens are primarily a tropical herbivorous species most at home in areas of shallow, sandy flats abundant with seagrasses. Their low protein vegetarian diet causes green turtles to grow and sexually mature slowly. Greens will reach maturity anywhere between 15 and 50 years of age.
Leatherback Turtles
Leatherback turtles are highly specialized and the largest and deepest diving of the sea turtle family. Individual leatherbacks range in length between 4 and 8 feet, and can weigh anywhere between 700 and 2000 pounds. Unlike other species of sea turtle, leatherbacks are scaleless, covered instead with a firm, rubbery skin lined with 7 longitudinal ridges. Leatherbacks may travel up to 3100 miles from their nesting beaches which are found on tropical and subtropical shores. They will visit Florida’s beaches to nest between April and August each year. In 2000, 453 nests were counted in Florida and 35% of those were in Palm Beach County.
The majority of Palm Beach County nests are laid from Singer Island north to Jupiter Inlet Colony. It is estimated that there are between 70,000 and 115,000 breeding female leatherbacks worldwide but most populations are declining dramatically.