2017-07-01 / Features

I’ve got friends in wet places …

By Glenda Caudle

They got off to “slow” start, but sea turtles in this area seem to have ramped up their activity of late, and the current nesting season is on track to set a record for the number of nests made on local beaches.

Sea turtles are reptiles. They breathe air and live, the majority of the time, in a marine environment, including the Gulf of Mexico and all tropical areas of oceans.

Around the world, a handful of species exist, but the most common species in this area – inside the Bay and around the Gulf of Mexico – are loggerheads. Green turtles and Kemp’s Ridley turtles are present, as well.

Leatherback turtles are also found in the area, but farther offshore.

Female turtles come ashore to nest beginning in May, with most of those laying nests on local beaches being loggerheads. The average incubation time is 60 days for their baby turtles to hatch and, during that time, staff and volunteers keep a close eye on the area to protect the unhatched and the just-born ones.

This includes sunrise patrols, each day, that cover every linear foot of Gulf beaches.

Once a turtle nest is spotted, it is marked with wooden stakes and signs and its location and the date of its discovery are entered into a data base so observers can start listening and watching for signs of hatching from 50-60 days out.

Most nests are about 1 ½ feet into the ground, but they can be anywhere from 12-24 inches deep. Depending on the species, each nest will serve as a haven for 100-140 baby turtles until they are ready to head up to the surface and, eventually, the water that will be their future home.

That’s when things can get a little dicey.

Marine biologists hope, of course, for a 100 percent survival rate, but count the nesting season successful if 90-95 percent of the little turtles make it to the waves. Unhappily, estimates put the percentage of turtles who actually make it into their preferred habitat at around 80 percent.

During America’s period of colonization, turtles and their eggs were regularly harvested as a food source. In fact, they were fished all the way into the late 20th century. In those earlier times, there was a better balance of nature. Over time, that balance shifted precariously, and not in favor of the turtles.

In the 1970s, the government recognized several threats to the sea turtle population and put laws into effect to protect them. These days, commercial shrimpers’ nets must carry turtle excluder devices – trap doors -- so that the creatures are not held captive and injured or killed. Fishing gear can also entangle turtles and lead to their demise.

Female turtles run into big problems when they come ashore to dig nests, so Escambia County recently instituted a “leave no trace” ordinance to keep Gulf-front beaches free of chairs, tables and canopies that would prevent the mother-to-be from finding a favorable nest site.

There is really no good way to protect turtles from accidental run-ins with boats and, every year, two or three hard-shelled bodies wash ashore from such accidents.

Male turtles don’t come ashore, unless they are injured. They mate in the water, and hope they don’t get done in by another threat to turtle survival – cold stunning. That happens when there is a strong cold snap that can be death to cold-blooded animals

Another major problem occurs when the hatchlings emerge and begin the essential journey toward water. In heavily populated well-lit areas on the opposite side of the nests from the water, the baby turtles often become disoriented and head for “bright lights, big city,” rather than the shoreline.

When a sea turtle comes out of the nest, it should be able to discern the faint glow of the shoreline, with the waves breaking on the white sand. All it should see landward would be a dark, vegetationcovered dune. The turtle looks for a band of low elevation bluish-green light, but what they may find, instead, is a bright horizon in the opposite direction of the Gulf, so they turn and head away from water. They go across roads and get hit by cars or they use up all their energy trying to find the water.

Females come ashore mostly at night to lay eggs, and hatchlings – which are just a little larger than the bowl of a tablespoon -- emerge mostly at night to make it into the Gulf. Then they swim like crazy for up to 24 hours to get away from the near-shore environment, where there are a lot of predatory fish. At that point, researchers lose track of them. They call it the “lost years.”

Maturing turtles get caught up in floating sea weed and marine biologists just don’t encounter them until they return to near-shore waters for feeing in their late juvenile periods. They see the adults when they come to mate in the near-shore waters, too, and when the females come ashore to dig their nests and lay their eggs.

Females will come ashore several times to lay nests during a season. Then, they typically take a year off. They do their best to camouflage their nests by throwing sand over them, then head back to the water before sunrise, their parenting duties at an end. Their offspring will be responsible for raising themselves from that point on.

Humans are not the only egg-thieves.

Raccoons and coyotes love digging up nests and devouring the eggs, as do dogs. There are local ordinances to prevent dogs’ running loose on the beach where they can forage for the nests.

To offer hatchlings as much protection as possible, staff and volunteers hunt diligently for new nests, mark them and then sit on the beaches in that area at night to wait for the nests to suddenly erupt with myriad small black creatures. If some interpret their built-in visual directional signals incorrectly and head away from the shoreline, the humans carefully gather them up in plastic bins and take them to the beach slope, so they can find water.

A turtle’s ability to navigate is tremendous,marine biologist say. Green turtles migrate across the Atlantic Ocean to Ascension Island in the eastern Atlantic, all the way from the coasts of North and South America. Then the females return to their own natal beaches to lay their eggs.

No one knows what cues are being used by sea turtles; it could be some olfactory clue or something connected to the earth’s magnetic field, or it could be celestial navigation.

Scientists think that initial run to the Gulf (of newly hatched turtles) somehow sets their internal compasses so they can swim in that direction for the first 24 hours. That won’t happen if the turn the other way. There are many studies on this with artificial sunlight, star patterns and artificial magnetic fields to determine the source of this amazing ability, which is very similar to that of migratory birds.

The temperature of the sand, during incubation, determines whether the turtles that hatch are male or female. Warmer layers of sand result in girl turtles, while cooler sand makes boy turtles.

Hatchlings eat jelly fish and pretty much anything else they can handle in the upper column of deep water. As they mature, loggerheads, in particular, may consume mollusks and crustaceans. Green turtles prefer sea grass and macroalgae.

While they plod on land, turtles can swim faster than scuba divers. Leatherbacks, the speediest, can do short bursts of 5-10 miles an hour.

Turtles are part of the natural eco-system and part of the fabric of life, marine biologists say. You don’t want to tear it and cause an animal or a plant to go extinct.

As coastal residents, a lot of us “get it.” The challenge is educating visitors who come in turtle nesting season.

Advice for the untrained beach walker who may happen upon a turtle nest eruption on a moonlit night includes the following: Don’t shine a flashlight beam on them. Don’t use any external light. Volunteers use a special red lens to illuminate only when absolutely necessary.

Also, people who live or work on the barrier islands should take care in nesting season not to allow any external light to hit the beaches. You don’t have to live right on the shoreline for your light to affect them. Even lights on the Gulf Breeze Peninsula can be seen from the beach. It is also vital to maintain a healthy frontal dune system. That provides a darkening on the horizon behind the turtles so the only light they see is the Gulf.

And if you see a turtles or turtles, which are protected creatures, in distress, call (850) 595-FISH (3473).

And don’t be slow about it.

Editor’s note: Special thanks is extended to Mary Easley, who offered editorial assistance on the story.

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