There is no other reptile in the world that is more wide spread than the sea turtle.

Evidence to this the fact that there is corner of the worlds tropical oceans that you will not find one or more of the ocean’s seven species of sea turtles at one time. Five of those species are native Atlantic Ocean alone, and are no stranger to Florida’s east coast.

Because the remarkable creatures have a strong affinity to the Palm Beach County Coast, your chances of meeting any one the fabulousfive during a dive are very good.

So, get started we begin with our most endearing resident of the reef.

 

Loggerhead (Caretta caretta) Sea Turtle

 

Easily recognizable by its thick rough textured shell and large blunt, almost boxy shaped head – which looks like the end of a log, hence the name, Loggerheads (Caretta caretta) are wide spread species found in both the Atlantic and Pacific Oceans. While most fully mature turtles average around 4 feet / 1.2 meters in length, it’s not unusual to come across adult females measuring 5 feet / 1.5 meters in length, weighing in at close to 500 lbs. / 226 kgs. In addition to being the third largest (in terms of weight) among marine turtles, they are also omnivorous, dining on just about anything they can get – jellyfish, crustaceans, even dead fish when they find it. This one dietary habit has made them highly susceptible to long lines set by commercial fishermen.

In Florida’s Palm Beaches, the opportunity to meet a loggerhead face to face, is typically not a matter of if, but when, as they are the first large creature divers are likely to encounter on the reef. This is not surprising, considering the Florida coast is one of top leading reproductive grounds for this impressive creatures from May to end of August.

During the height of loggerhead nesting season (June/July) resident turtles are joined by transient individuals, causing the population to more than triple in number. Off shore on the reef tracks in the 60-foot range between Jupiter and Boynton Beach, divers have describe themselves as being out numbered by turtles, running across as many as 15 to 30 plus large turtles bedded down for a nap on the reef during the course of single drift dive.

When turtles nest, it is typically at night when they emerge from the sea and crawl straight up the beach to a suitable spot to dig a hole and lay their clutch of eggs. On average, sea turtles lay between 90 and 110 eggs in single clutch. During the span of one summer nesting season its quite common for individual turtles to make as many as 6 to 8 visits ashore. To haul such a large body that was not designed to function on land, up a sandy slope to perform such a task, including covering the eggs up before they crawl back into the ocean, a process encompassing 1 and 1.5 hours to complete, takes a great deal of physical effort. As such, the turtle is so highly fatigue the only thing they that will on their mind, is find someplace safe to sleep it off.

The most telling evidence that one of these grand ladies had just made it back to the reef is their sometimes comical appearance of having settled in with only their head stuck up under a ledge too small for the rest of their body to fit. A scene that that often brings to mind of someone attempting to park a large truck in small backyard tool shed.

 

Atlantic Hawksbill (Eretmochelys imbricata) Sea Turtle

 

Next to Loggerheads, the Atlantic Hawksbill (Eretmochelys imbricata) is the second most abundant species of sea turtle off this coast.

Smaller and more agile, Hawksbill’s are easily identified by their protruding upper jaw, which resembles a hawk’s beak and highly recognizable ornate coloration in their shell. It was because of the unique color pattern in their shells once made them highly sought after for tortoise-shell jewelry and ornaments. Nowadays, their biggest dangers are development of nesting beaches and poaching of their eggs, despite their global protected status.

An interesting factoid about hawkbills is that they do not nest on beaches along Florida Southeast coast. Instead, their primary nesting grounds take place in the Caribbean, plus nesting is not seasonal, but instead takes place year round. Most of the Hawksbill turtles we see are juveniles that are two to three feet in length, and not yet sexually mature. A fully mature adult will measure 45 inches / 1.1 meters in length, weighing around 190 pounds / 86 kgs. If you run into a larger Hawksbill, it’s likely a transient that’s just passing through.

While most sea turtles are omnivorous (only the leatherback exclusively feed on sea jellies), Hawksbills have a particular taste for sponges, which constitutes 70–95% of the turtles’ diets.

The variety of sponges resident hawksbills in the Caribbean and Tropical Atlantic primarily feed on belong to the Class Demospongiae, such as giant barrel sponge (Xestospongia muta), common loggerhead sponge (Spheciospongia vesparium), the Caribbean Chicken-liver sponge (Chondrilla nucula), and the Orange ball (Tethya actinia) sponge.

A good indication that one spongivores have been at work is when you find a sponge with golf ball size divots carved out of the side larger size sponges.  

Some of the sponges these spongivores like eat are especially not for those with a weak stomach. Some contain a significant amount of siliceous spicules, such as White (Geodia gibberosa) and Star (Placospongia) encrusting sponges. And then there are those are highly (often lethally) toxic to other organisms. One of those highly toxic species is the Suberites domuncula, small globular shape sponge generally brownish orange in color that contains a neurotoxin that can cause fatal hemolytic hemorrhaging in various animals, yet hawksbills have no problem adding them to their list of edibles.

Aside from sponges, they will sometimes dine on the dangerous jellyfish-like hydrozoan, the Portuguese man o’ war (Physalia physalis). When they do this, Hawksbills close their unprotected eyes as the man o’ war’s stinging cells cannot penetrate the turtles’ armored heads.

Final big surprise, the hawksbill sea turtle was recently discovered the ability to display biofluorescent; not only the first sea turtle with this characteristic, it’s also the first reptile recorded with ever. Considered that many organisms like the hard corals and sponges are biofluorescent, it’s not really that much of a reach how or even where the Hawksbill gets it. As the expression goes, sometime you are what you eat.

 

Atlantic Green (Chelonia mydas) Sea Turtle

 

Green Sea Turtles (Chelonia mydas). Second largest in the sea turtle family, an adult female can grow to 5 feet / 1.5 meters in length with some individuals weighting as much as 690 pounds / 315 kgs. Most adult greens seen on the reefs here in Palm Beach average between 240 and 420 pounds / 110–190 kgs., which is still pretty big.

Although similar in size to Loggerheads, Greens are really easy to identify by their smooth, olive-brown carapace (shell) marked with darker brown streaks and/or spots, and equally smooth bullet shaped head. The name Green sea turtle was actually derived from the greenish color of its body fat, not its skin or shell.

In addition to having a relatively long lifespan of up to 70-80 years, Green Sea Turtles are primarily nomadic, migrating from feeding grounds to the nesting grounds of their birth and back again. While most follow coastlines, some will move across the open Atlantic. For example, one population swims from Brazil to nesting grounds on Ascension Island, which is about 1,000 miles / 1,600 kilometers off the coast of Africa.

Compared to the abundance of Loggerheads and Hawksbills, Greens come up in third place off the Florida coast. Most the Greens spotted by divers are typically juveniles less than two feet in length, but come early June to August a good number of adults come to the Palm Beaches between to lay their eggs up on the beach.

The one thing to keep in mind when looking for a Green sea turtle is watch the water above your head as much as the reef as Greens typically don’t rest as often Loggerheads, even after a night’s journey ashore.

 

Leatherback (Dermochelys coriacea) Sea Turtle

 

As large sea turtles go, the Leatherback (Dermochelys coriacea) is a colossus.

At full maturity, a Leatherback will measure 4 to 6 feet / 1.2 to 1.9 meters in length, and weigh from 440 to 1,100 pounds / 200 to 500 kgs.  The largest Leatherback recorded was 6.5 feet (1.98 meters) in length, and tipped the scales at 2,019 pounds (915 kg), making it a colossus in the world of living sea turtles. In the water or on the beach, there is no mistaking this creature with it is predominantly black body with white markings, and a teardrop-shaped leathery carapace instead of a hard shell.

Adding to this size factor, is perhaps they are the most intriguing of all them all as they are both a throwback to the height of their evolutionary development, some 75 to 100 million years ago, when sea turtles had obtained the size of giants. The largest of these was a species called Archelon (Greek meaning ruler turtle), which grew to 13.5 feet / 4 meters in length, with a flipper span (from tip to tip) of 16 feet / 4.9 meters. The largest Archelon fossil was unearthed in the 1970s in South Dakota’s Pierre Shale region, which was a shallow sea during the late Cretaceous period 75-65 million years ago. Like their ancestral forerunner, Leatherback sea turtles differ from the rest of present day sea turtles in that they do not have a solid shell, but instead have a skeletal framework covered by a leathery carapace.

At the other end of the spectrum, they feature remarkable adaptations for life in the open sea, including a large amount of oil in their bodies, which gives them their unique ability to maintain their core body temperatures in waters cold enough to kill easily kill other species of sea turtles. An important feature, considering that many of the jellyfish they prey upon are found more readily in the northern and southern latitudes of the Atlantic, Pacific and Indian Ocean. In the Atlantic, leatherbacks regularly inhabit regions as for north as Maine to as far as South as South Africa’s Cape of Good Hope.

Because they are still reptiles, they require more tropical and subtropical climes when it comes time to nest and lay eggs. The most significant Atlantic nesting sites are in Suriname, French Guiana and Trinidad and Tobago in the Caribbean, and Gabon in Central Africa and of course Florida with Palm Beach County beaches accounting for just shy of 30% of total leatherback nests laid in the state of Florida.

Since 2001, the Loggerhead Marinelife Center on Juno Beach have been highly involved in monitoring the nesting behavior, the rate of occurrence of nesting behaviors of leatherback where they have accumulated a database of more than 360 individuals. The epicenter of this activity beginning as early as March, running primarily during April and May taking place between the Jupiter Inlet and the Lake Worth Inlet.

While in the area, a female may come ashore as many as eight or nine times, over a 12-week period, laying a clutch of up to 100 eggs with each landing. Their egg laying ends between mid May and early June. Using satellite tags, the Loggerhead Marinelife Center have also been able to follow as many as 25 of these turtles with several journeying for north as Newfoundland and eastward to the coast of Africa.

 

Kemp’s Ridley (Lepidochelys kempii) Sea Turtle

 

In addition the Palm Beach County Coast being known for finding loggerhead, Hawksbill, Green and Leatherback sea turtls, there is a fifth species, the Kemp’s Ridley (Lepidochelys kempii).

The Kemp’s physical appearance can be little confusing at first often raising the question, is that a medium size Green or is it a Medium size Loggerhead?

While the head carries some resemblance to a Loggerhead, just not as robust, their shell is smooth like a Green’s, and the coloration is more light tan to grey, than dark brown.

Another characteristic to the Kemp’s carapace (shell) is that it is profile semi-flat compared to other species, as well as significantly more rounded in shape when viewed from above.

Along with their Eastern Pacific kin, the Olive Ridley (Lepidochelys olivacea), the Kemps are the smallest species of sea turtle, reaching maturity at 2 to 3 feet / 60 to 90 cm in length, averaging no more than 100 lbs. / 45 kgs. in weight.

At one time, the Ridley were the most prolific species of sea turtles in the Gulf of Mexico, ranging from as far north as the coast of Alabama southward to the Campeche Bank, near the Yucatan Peninsula. Colonial records from the early 1700-1800’s describe the beaches on both sides of the Gulf as being covered by nesting turtles.

Hunting and coastal development took a toll on the turtle population. By 1947, it was estimated that the entire nesting population of Ridley’s in the Gulf numbered around 92,000. The first large scale surveys conducted between 1978 and 1988 revealed alarming decline, with the number of nests having fallen to around 800, and a continuing downward trend of 14 fewer nests each successive year. Today, the total number of nesting females may be as low as 350 through out their entire range.

Although found predominantly the Gulf of Mexico, an extremely small population of Kemp’s Ridley sea turtles reside off Florida’s eastern coast between Jacksonville and the northernmost end of the Palm Beaches.