Sea Turtle Nesting
By Bill Edmonds
It’s sea turtle nesting time again. One of my favorite times of the year in Florida. We are so lucky to have these beautiful beaches for people to use for swimming and sun tanning. But late at night they turn into quite a different place to be. Take a walk down the coast line . The water splashes up on the beach, it’s warm and feels great on your bare feet. The moon is behind you over the land and the stars twinkle all around. Looking out at the commercial fishing boats collecting shrimp for the next day’s market you might notice a very large object at the foot of the beach where the water splashes from the most recent wave. Kind of looks like maybe a big log or some kind of debris. You stop and stare because it’s moving and walking up on the beach. It’s huge and dark, but definitely coming out of the water. Your heart starts pounding, what is it? Well it’s a beautiful female Loggerhead turtle coming ashore to lay a clutch of eggs. She has been to sea for a year or more and she has come back to the place she was born to perpetuate her species. What a beautiful site as she lumbers up the beach towards the dry warm sand. If you come back in thirty minutes you can see sand flailing into the air. She has started her nest. This is when I sit down and make myself comfortable. She is busy digging and I am careful to stay behind her and out of the way of the sand. I have a red flash light so I can keep track of her progress, but she can’t see the red light. She can dig for an hour, first a wide depression that she settles into Then a large coffee can sized hole towards the back of the depression. Almost like a tear drop and just right to fit her eggs. She will move around to get into the position she wants to be then she starts to lay her eggs. One after another, filling the perfect hole she made for them. She grunts and moves, her large head laying on the sand. She lays a hundred eggs. Some times more or less. This can take an hour. And when she has finished she starts to cover the hole with her back flippers, packing the sand just right. Then she moves forward
and starts to fill the depression she was laying in. You need to get out of the way at this point because the sand really starts flying. She flings it into the depression and all around where she has been. Hiding the location from any predators that might be looking for a meal. Now tired and spent from the work she has been performing for over two hours. She starts her way back from whence she came. This is the time, right before she disappears into the ocean I will sometimes snap her picture. Any other time and
she will abandon the effort and not lay. Covered in sand , the waves wash over her until she becomes buoyant and swims back out into the darkness. Disappearing until she comes back to lay again fourteen days later. Up to four times she will repeat this behavior during the nesting season between April and September.
Florida Sea Turtle Information
Five species of sea turtles that inhabit Florida’s waters during some of the year. Florida’s nesting sea
turtles include the loggerhead (most common), and leatherback (least common). During the summer
months, there are approximately 50,000 sea turtles in Florida. This makes it the most important nesting area in the United States. Other species of sea turtles that frequent Florida waters but generally do not nest here include the Hawksbill and the Kemp’s Ridley.
The loggerhead sea turtle, or loggerhead, is an oceanic turtle distributed throughout the world. The average loggerhead measures around 35 in long when fully grown, although larger specimens of up to 110 in have been discovered. The adult loggerhead sea turtle weighs approximately 298 lb, with the largest specimens weighing in at more than 1,000 lb. The skin ranges from yellow to brown in color, and the shell is typically reddish-brown. No external differences in gender are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons than the females. The loggerhead sea turtle has a low reproductive rate; females lay an average of four
egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years. The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Along the southeastern coast of the United States, the raccoon is the most destructive predator of nesting sites. Mortality rates of nearly 100% of all clutches laid in a season have been recorded on some Florida beaches. This is attributed to an increase in raccoon populations, which have flourished in urban environments. Aggressive efforts to protect nesting sites by covering them with wire mesh has significantly reduced the impact of raccoon predation on loggerhead sea turtle eggs. Hatchlings range in color from light brown to almost black, lacking the adult’s distinct yellows and reds. Upon hatching, they measure about 1.8 in and weigh about 0.7 oz. The eggs are typically laid on the beach in an area above the high-tide line. The eggs are laid near the water so the hatchlings can return to the sea. The loggerhead’s sex is dictated by the temperature of the underground nest. Incubation temperatures generally range from 79-90 °F. Sea turtle eggs kept at a constant incubating temperature of 89.6 °F become females. Eggs incubating at 82.4 °F become males. Artificial lighting discourages nesting and interferes with the hatchlings’ ability to navigate to the water’s edge. Females prefer nesting on beaches free of artificial lighting. On developed beaches, nests are often clustered around tall buildings, perhaps because they block out the man-made light sources. Loggerhead hatchlings are drawn toward the brighter area over the water which is the consequence of the reflection of moon and star light. Confused by the brighter artificial light, they navigate inland, away from the protective waters, which exposes them to dehydration and predation as the sun rises. Fishing gear is the biggest threat to loggerheads in the open ocean. They often become entangled in longlines or gillnets. According to the 2009 status review of loggerheads by the Fisheries Service, drowning from entanglement in longline and gillnet fishing gear is the turtles’ primary threat in the North Pacific. They also become stuck in traps, pots, trawls, and dredges. Caught in this unattended equipment, loggerheads risk serious injury or drowning. Turtle excluder devices for nets and other traps reduce the number being accidentally caught. Turtles ingest a wide array of floating debris, including bags, sheets, pellets, balloons and abandoned fishing line. Loggerheads may mistake the floating plastic for jellyfish, a common food item. The ingested plastic causes numerous health concerns, including intestinal blockage, reduced nutrient absorption and malnutrition, suffocation, ulcerations, or starvation.
The green sea turtle (Chelonia mydas), also known as the green turtle, black (sea) turtle, or Pacific green turtle, is a large sea turtle of the family Cheloniidae. This species is named for the green color of its fat, rather than the color of its skin or shell as most people think. These turtles shells are in fact olive to black.
flattened body is covered by a large, teardrop-shaped carapace; it has a pair of large, paddle-like flippers. It is usually lightly colored
The adults usually inhabit shallow lagoons, feeding mostly on various species of seagrasses. The turtles bite off the tips of the blades of seagrass, which keeps the grass healthy.
Like other sea turtles, green sea turtles migrate long distances between feeding grounds and hatching beaches. Many islands worldwide are known as Turtle Island due to green sea turtles nesting on their beaches. Females crawl out on beaches, dig nests and lay eggs during the night. Later, hatchlings emerge and scramble into the water. Those that reach maturity may live to eighty years in the wild.
The diet of green turtles changes with age.Juveniles are omnivorous, but as they mature they become exclusively herbivorous.This diet shift has an effect on the green turtle’s skull morphology. The young will prey on invertebrates, worms, algae, and crustaceans. Adult green turtles consume so many plants and algae, their flesh becomes greenish in color.
Adult green turtles grow to 5 ft long. The average weight of mature individuals is 150–419 lb and the average carapace length is 31–44 in Exceptional specimens can weigh 694 lb or even more, with the largest known green turtle having weighed 871 lb and measured 60 in in carapace length.
The range of the green sea turtle extends throughout tropical and subtropical oceans worldwide.
Their native range includes tropical to subtropical waters along continental coasts and islands between 30° N and 30° S. Since green sea turtles are a migrating species, their global distribution spans into the open ocean.
In the United States Atlantic coast, green sea turtles can be found from Texas and up to Massachusetts.
The largest population of green sea turtles within the United States coastline are in the Hawaiian Islands and Florida.
Within United States waters, minor nesting sites have been noted in the states of Georgia, North Carolina, South Carolina, and all along the east coast of Florida.
Sea Turtles Found in Florida Green Turtle Named for the Green color of its body fat, this turtle is listed as endangered in Florida. Most Green turtles nest in the Caribbean, but up to 2000 nests can be found in Florida each year. For centuries, Green turtles were hunted for their meat that was made into soup. Hunting and egg gathering greatly reduced their number. Green turtles graze on the vast beds of sea grasses found throughout the tropics and are the only sea turtles that eat plants. Some travel over a thousand miles to nest on islands in the mid-Atlantic. Hawksbill Turtle This turtle is a relatively small turtle, and has been hunted to the brink of extinction for its beautiful shell. Once relatively common in Florida, these turtles now rarely nest here. They feed on sponges and other invertebrates and tend to nest on small, isolated beaches. Leatherback Turtle This endangered turtle is the largest and most active of the sea turtles. Up to eight feet in length, these huge turtles have a rubbery dark shell marked by seven narrow ridges that run the length of their back. Many travel thousands of miles and dive thousands of feet deep. They also venture into much colder water than any other sea turtle. These turtles feed on jellyfish and soft-bodied animals that would appear to provide very little nutrition for such huge animals. Ingestion of plastic bags and egg collecting are reasons for mortality and population declines. About 200 leatherback nests are recorded in Florida each year. Kemp’s Ridley The rarest and smallest of all the sea turtles, this endangered turtle feeds in the coastal waters of Florida on blue crabs, other crabs and shrimp. They nest on a single stretch of beach on the Gulf Coast of Mexico. Loggerhead Turtle This is the most common sea turtle in Florida. It is classified as a threatened, but not endangered species. Named because of its large head, which can be ten inches wide, it has powerful jaws used to crush the clams, crabs and encrusting animals on which it feeds. As many as 68,000 loggerhead nests have been found in Florida each year