Loggerhead Sea Turtles
March to October is a busy time in the waters off Jupiter, Florida as sea turtles return to the Palm Beaches to breed and nest. Green, loggerhead and hawksbill sea turtles are the three most common species found off our shores, and they are easy to tell apart once divers know what to look for. A fourth species, the leatherback also nest in the area, but they are far less common. We wrote about leatherbacks in February. Today, let’s talk Loggerheads.
First a bit of background.
Loggerhead sea turtles are the most common sea turtle in Florida. Unfortunately, the term “most common” doesn’t mean there is a thriving population, and the World Conservation Union (IUCN) lists loggerhead sea turtles as endangered.
Loggerheads earned their name because of a distinctive part of their anatomy–they’ve got big heads. They are carnivorous and their diet consists of mainly crabs, fishes, and jellies; although sometimes they’ll munch on seaweed as well.
Sea turtles of all species are cold blooded, so warm water is critical to their survival. Loggerhead sea turtles can be found in coastal waters, and they occasionally travel inland. Hatchlings live in the Sargassum mats found floating several miles offshore.
How to identify a loggerhead sea turtle.
The first clue is in their name. Compared to other sea turtles, they’ve got a large, reddish-brown head. Loggerheads weigh in between 200 and 350 pounds and typically measure about 3 feet in length. Their carapace (shell) is also reddish-brown in color.
The Sea Turtle Life Cycle
Sea turtle eggs incubate in warm sand for approximately two months before the baby sea turtles hatch. These hatchlings almost always emerge at night and instinctively dart toward the ocean. (More on the importance of Dark Sky initiatives on June 27 when we talk about green sea turtles.) Once the hatchlings reach the ocean, they’ll swim for days to reach the open ocean currents.
Little is known about sea turtles’ first five to ten years of life, but once they leave the protection of the flotsam, they’ll forage in coastal areas bulking up. Once they reach sexual maturity, natal homing kicks in and guides the adult sea turtles to the beach where they were born. Offshore, the turtles will mate. Under the cover of darkness, the females will haul themselves onto the beach, dig a hole in the sand, and lay a clutch of eggs that typically averages between 40 and 200 eggs (yes, 200!).
Females will remain offshore for a few weeks then return to the beach to lay another clutch of eggs. They can do this between two and seven times before they’ll depart their natal beach and return to their foraging grounds—which may be hundreds or thousands of miles away.
This brings the cycle full circle. Hatchlings are vulnerable, and face many hazards. Biologists believe that less than one in 1,000 sea turtles survive to adulthood.
We are lucky, indeed, to dive in an area where so many sea turtles call home. What are you waiting for? Join us and see them for yourself!