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Originally appears in the Fall 2018 issue.
A WOMAN STOOPS OVER and peers intently at the waves lapping against the sand on the Sanibel Island shoreline as she looks for ocean treasures of spiraled Florida conchs and swirled lightning whelks. Moments later, a clap of thunder draws her attention toward the sea. As she stares into the water, a huge mass emerges from the ocean directly in front of her. It slowly shuffles out of the water and onto the beach. The woman grabs her bag of shells and frantically waves to her daughter, who gets up from her towel to watch the algae-covered mass stop and begin to shift the sand out from underneath itself. They are witnessing a loggerhead sea turtle uncharacteristically laying eggs during the day — probably to avoid an oncoming storm.
Like most loggerheads, this four-foot-long turtle has a streamlined shell with barnacles scattered across its brown surface. Her nest is one of five that she will dig sequentially during the summer nesting season, each producing around 110 hatchlings. This turtle most likely migrated hundreds of miles to dig her nest, and she will take a well-deserved two-year vacation before nesting again.
The mother and daughter excitedly call the Sanibel turtle nesting hotline to report the location of the new nest. The volunteers arrive within the hour and begin to monitor the unusual daytime nesting. When the loggerhead sea turtle is finally done burying her eggs, she ponderously shuffles back into the ocean, leaving tracks as deep as those of a small tractor. The volunteers immediately place a screen around the nest to protect the eggs from predators and unwary beachgoers. The screen has wide enough gaps through which hatchlings can emerge on their way back to the sea two months later. The lifespan of a loggerhead sea turtle can last as long as 90 years — so long that a grandmother sea turtle can nest at the same time as her granddaughters, even though it takes 30 years for a loggerhead to become reproductively active.
Even with their long lifespans, loggerhead sea turtles are threatened. Many hatchlings do not make it from the nest to the sea due to predation by ghost crabs and seabirds, or because of human interference: sea turtles can be confused by artificial lights onshore or human-made obstacles such as beach chairs and sandcastles. The survival rate of loggerhead sea turtle hatchlings would be about 1 in 10,000 if the nests were left unprotected and hatchling emergence was not monitored. With the efforts of conservationists, the survival rate is closer to 1 in 1,000, which still equals only one surviving offspring per turtle every 20 years.
When the loggerhead sea turtle is finally back in the sea and the volunteer staff are finished securing the nest, the mother and daughter retreat to their beach condo where they immediately begin looking up everything they can about loggerhead sea turtle conservation. Meanwhile, a storm settles in and rain pours onto the new turtle nest outside.
The mother and daughter’s research reveals the overlooked significance of the beach as a unique natural habitat, and also highlights the beach as an optimal location for environmental education. Dr. Blair Witherington, a sea turtle biologist, explains that “children are increasingly divorced from nature and connected to technology. They are missing important nature experiences.” He says that the beach has much more to offer than sun and sand. It represents an opportunity to go outside of a textbook to teach our children about beach wildlife and the importance of preserving coastal ecosystems.
Dr. Witherington and his wife Dawn Witherington, a scientific illustrator, have spent their careers on beaches learning and adding to their books, Florida’s Living Beaches: A Guide for the Curious Beachcomber and Our Sea Turtles: A Practical Guide for the Atlantic and Gulf. Dr. Witherington describes his work as a turtle conservationist and beachcombing enthusiast as an endless adventure on the beach. He says, “The ocean is so dynamic. It changes depending on the season and the general mood of the ocean. You could spend lifetimes studying beach life. And the best part is that you do not have to wear shoes while you do it.”
Inside a Coastal Ecosystem
While it may be difficult to catch a loggerhead sea turtle in the act of nesting, common beach life is full of interesting facts and educational opportunities. Look out over the ocean and you might spot some brown pelicans. They will have certainly spotted you. Brown pelicans can see fish from 20 to 60 feet away. They will fly in a straight line or V-formation close to the water to take advantage of the “ground effect.” Pilots mimic this behaviour as the “ground effect” makes flying nearly effortless by compressing airflow and reducing drag, which is a force that acts opposite to motion. When an unsuspecting fish is selected, the pelican will dive for its prey, scoop the fish up in its pouch, land on the water to drain the seawater from its bill, and then swallow the whole fish headfirst to avoid damage from the fish’s sharp scales.
The brown pelican is common on both the Atlantic and pacific coasts, and it is one of many kinds of birds that you can expect to find at the beach. You can research other birds that are in season or even obtain a bird guide for your area. Birdwatching can instigate basic environmental science questions. For example, how does a bird species fit into the food chain? Does it migrate? Is it endangered? The answers to these fundamental questions become memorable for kids when coupled with the experience of actually spotting the bird.
Now, look down along the sand and you may notice an empty clam shell with a hole in it. This shell was the skeleton of an organism in the Mollusca phylum and was supposed to act as a protective outer covering to its owner. However, the telltale hole is the only remaining evidence of the agonizingly slow death of the clam at the hands of a ruthless predator: the snail.
Common moonsnails and shark eye snails plow through the sand “smelling” for prey, including proteins from clams. A clam will attempt to flee to the sand’s surface in response to a snail’s approach. Thus, a thrilling yet sluggish race ensues between predator and prey. If the unlucky clam is slower than the snail, the snail will envelop it with its foot and release an acid that softens the clam’s shell enough to bore a hole in it. It will then release enzymes that digest the clam’s adductor muscles. Without these muscles, the clam pops open like a cracked safe and, bon appétit, clam chowder is served.
While beachcombers often miss this slow-motion attack, the remains of empty clam shells and other colorful shells can be found and collected along the shore. You can introduce kids to the biology of shells via shell quests. Look up shells found in your region, rate them from common to rare, and include interesting facts about the diverse shells. You can even award points for finding certain shells to make it more of a competition, which helps to get older kids involved too!
Ensure that your students or children understand that empty shells also play a role in the environment. Shell surfaces can become microhabitats for algae, seagrass, sponges, and microorganisms. Some fish use larger shells as shelter from predators in the water. In addition, hermit crabs can use other shells as temporary homes, and birds even add shells to their nests. Most shells are ground in the surf by the tide to become grains of calcium carbonate, which is the main ingredient in sand. This shell-derived sand provides key habitats for beach creatures (as well as vacationers).
While beachcombing is educational and enjoyable, it is important for collectors to take shells from the beach selectively and sparingly. Dr. Witherington suggests taking pictures of most of your shell finds instead of removing them from the beach. He states, “We cannot forget that beaches are alive.”
Further Exploration
Many popular vacation destinations also have wildlife refuges and injured wildlife rehabilitation centers. Some even offer opportunities to interact with volunteers like the turtle conservationists who work with the Sanibel-Captiva Conservation Foundation. Sarah Lathrop, associate director of the Ding Darling Wildlife Society on Sanibel, encourages vacationers to do summer internships at a wildlife refuge. As she puts it, “Helping out wildlife can be as easy as picking up the trash you see along the beach.”
Beaches are prime relaxing travel destinations, but parents and teachers can also incorporate fun-filled and memorable nature experiences into their trips to the beach or even to inland lakes. Like ocean coastlines, lakeshores encompass diverse habitats that are home to abundant wildlife that could be the inspiration for birdwatching lists, quests for native plants, or hunts for freshwater mussels.
Dr. Witherington describes the Earth as a “vast wilderness. Every single day is different. You can never learn it all.” But we can provide our children with the opportunities to try.
Grace Satterfield teaches Biology to undergraduates at the University of Tennessee and researches plant-microbe interactions at Oak Ridge National Laboratory in Oak Ridge, Tennessee.