A Worldwide Travel Guide to Sea Turtles
240
A Worldwide Travel Guide to Sea Turtles
240eBook
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Overview
Sea turtle populations around the world are endangered, and in recent years tourism has been a critical element in worldwide efforts to save them. More travelers seek meaningful experiences that bring them close to nature and wildlife, and opportunities to interact with and help sea turtles now exist at locations around the globe, from remote beaches to urban labs.
In A Worldwide Travel Guide to Sea Turtles, a scientist, a conservationist, and a journalist have come together to provide a guide to the places where people can view sea turtles and participate in authentic conservation projects.
Covering five continents and including the South Pacific and Caribbean, the authors direct readers to the parks, reserves, and research sites where they can responsibly observe turtles in the wild, especially nesting beaches where people can see female sea turtles lay eggs and hatchlings make their harrowing journey from nest to sea. Options for on-site lodging and other amenities are included, if available, as well as details of other nearby attractions that travelers may wish to include in their itineraries.
Product Details
| ISBN-13: | 9781623491741 |
|---|---|
| Publisher: | Texas A&M University Press |
| Publication date: | 03/25/2014 |
| Series: | Marine, Maritime, and Coastal Books, sponsored by Texas A&M University at Galveston |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 240 |
| File size: | 19 MB |
| Note: | This product may take a few minutes to download. |
About the Author
WALLACE J. NICHOLS is a research associate at the California Academy of Sciences. He is past president of the International Sea Turtles Society and is the author of Blue Mind. He resides in the San Francisco area. BRAD NAHILL, of Beaverton, Oregon, is cofounder and director of SEE Turtles, a nonprofit organization seeking to protect sea turtles and other wildlife through conservation tourism. MELISSA GASKILL is a professional journalist with more than twenty-five years of experience writing about the outdoors, nature, and science. She lives in Austin.
Read an Excerpt
A Worldwide Travel Guide to Sea Turtles
By Wallace J. Nichols, Brad Nahill, Melissa Gaskill
Texas A&M University Press
Copyright © 2014 Wallace J. Nichols, Brad Nahill, and Melissa GaskillAll rights reserved.
ISBN: 978-1-62349-174-1
CHAPTER 1
Sea Turtles and the Threats to Their Survival
SEA TURTLES have changed little in the past 100 million years—appearing before and eventually outliving the dinosaurs. They swim nearly all the oceans of the world and were once so numerous that sailors reported seas literally crawling with them. Today, due to a variety of threats, six of the seven species of sea turtles are endangered or threatened. All over the world, they face challenges to their individual survival and that of their entire species, requiring unprecedented conservation efforts.
As reptiles, sea turtles breathe air but, over millennia, have evolved the ability to remain submerged for hours at a time while resting or sleeping. Their long, narrow front flippers and shorter, webbed back flippers allow them to dive to great depths and swim long distances. While some land turtles can pull their head and legs into their protective shell, sea turtles cannot. They lack teeth but have powerful jaws that crush, bite, or tear, depending on the food they eat.
Sea turtles may live for 80 or more years and can take 15 or more years to reach maturity. They spend their entire lives at sea, save the brief periods when females return to nest on the beach where they were born. Scientists are not completely sure how they find their way back, but research shows that sea turtles can orient to the earth's magnetic field, so it may play a role. As hatchlings, they likely also imprint to characteristics of the sand and water of their natal beach.
Mother sea turtles usually nest only every two or three years, but they may lay two or three nests in one year. The temperature in the nest determines the sex of the hatchlings, with warmer nests producing females and cooler nests resulting in more males. Incubation takes about six weeks to two months, and hatchlings often emerge as a group.
Sea Turtle Species
Olive Ridley(Lepidochelys olivacea)
IUCN vulnerable
US ESA endangered Mexico's Pacific coast, threatened all other areas
Olive ridleys are the most abundant sea turtle in the world, with perhaps 800,000 females nesting annually. They weigh 100 pounds on average as adults, with a heart-shaped carapace (top shell) about two feet in length, and one to two claws on the flippers. They eat algae, lobster, crabs, tunicates, mollusks, shrimp, and fish. The species gets its name from its olive, grayish-green color.
Olive ridley nesting has been documented in as many as 40 countries, generally June through December in the eastern Pacific. Sometimes large groups, called arribadas (Spanish for "arrival"), of hundreds to thousands of mother sea turtles gather offshore, then head en masse onto the beach to lay their eggs. Females also nest singly, and some do both. Theories concerning the reason for arribada behavior include protection from predators—the sheer numbers are simply too much for a natural predator population to eat all at once—but scientists do not know for sure why sea turtles do it. An estimated 10 million olive ridleys once nested on the Pacific coast of Mexico, but now only a single arribada nesting beach may remain there.
Found in tropical regions of the South Atlantic Ocean along the coasts of West Africa and South America, in the eastern Pacific Ocean along the coast from Southern California to Chile, and in the Indian Ocean, olive ridleys have suffered a 50 percent reduction in population since the 1960s.
Leatherback(Dermochelys coriacea)
IUCN critically endangered
US ESA endangered
The largest living marine reptile in the world at 500 to 1,500 pounds, leatherbacks can even grow as large as 2,000 pounds and more than six feet long. They are covered with a firm, leathery skin with seven lengthwise ridges, black with white, pink, and cobalt-blue highlights, with no claws on the flippers. These sea turtles can dive deeper—up to 3,000 feet—travel farther—more than 3,000 miles—and tolerate water colder than other sea turtles can. They eat jellyfish and other soft-bodied animals, and the scissorlike jaws and throat are lined with stiff spines to help them swallow such slippery prey.
Leatherbacks nest around the world, primarily now in Central America, northern South America, Trinidad, and West Africa; as well as in Indonesia; and in lesser numbers, Puerto Rico, US Virgin Islands, and southeastern Florida. According to the IUCN, the leatherback nesting population declined more than 80 percent between 1982 and 1996.
Loggerhead(Caretta caretta)
IUCN endangered
US ESA endangered Mediterranean Sea, North Indian Ocean, North and South Pacific Oceans; threatened northwestern Atlantic Ocean, South Atlantic Ocean, southeastern Indo-Pacific Ocean, southwestern Indian Ocean
Named for its relatively large head, an adult loggerhead weighs up to 400 pounds and measures about three feet long. Its carapace looks reddish-brown, broad near the front and tapering to a point, and creamy-yellow underneath. It has two claws on each flipper and powerful jaws to crush clams, crabs, conch, and other prey.
Nesting takes place late April to early September throughout temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans. The majority of nesting occurs along the western rims of the Atlantic and Indian Oceans, with aggregations in Oman, Australia, and the United States accounting for roughly 88 percent of total nesting. Major nesting concentrations in the United States are found from North Carolina to Florida—nearly 80 percent in six Florida counties—with some nesting farther north on the East Coast and into the Gulf of Mexico to Texas. Some loggerheads nest on the island-nation of Cape Verde off the coast of Senegal and in the Mediterranean. Females lay three to five nests or more in one season and prefer narrow, steep, coarse beaches. Tagging studies have documented that Pacific populations nesting in Japan cross the entire ocean to feed on crabs along the coast of Mexico's Baja California peninsula, a developmental migration of some 15,000 miles. (See the track of a turtle named Adelita at seaturtle.org/tracking/adelita.)
Green (Chelonia mydas)
IUCN endangered
US ESA endangered Florida and Mexico's Pacific coast, threatened all other areas
This species weighs an average of 300 to 350 pounds as an adult, with a smooth, oval-shaped shell about 3.3 feet in length, olive-brown with darker streaks and a yellow plastron, or belly. Juveniles are omnivorous, but adult greens are the only herbivorous sea turtles, eating primarily seagrasses and algae.
Found in tropical and subtropical waters primarily between 30 degrees North and 30 degrees South latitudes, they are common around Baja California and Hawai'i, where they are referred to as black sea turtles or Pacific green sea turtles, which range from Southern California to Chile. Greens nest June to September in the southeastern United States, most of them in Florida. The largest nesting populations are found at Tortuguero on the Caribbean coast of Costa Rica and on Raine Island on Australia's Great Barrier Reef.
Hawksbill (Eretmochelys imbricata)
IUCN critically endangered
US ESA endangered
Weighing 100 to 200 pounds at maturity, hawksbills have a carapace about 30 inches long, with black and brown markings on a background of amber, with overlapping scutes, or scales, and a serrated rear edge. These beautiful shells, known incorrectly as tortoiseshell, are coveted for jewelry, hair decorations, and other items, and many hawksbills have been killed to support this mostly illegal trade. This species uses the raptorlike jaw for which it is named to eat sponges, which are made of tiny, glasslike needles.
They live mostly between latitudes of 30 degrees North and South in the Atlantic, Pacific, and Indian Oceans and are found in southern Florida and the Gulf of Mexico, Puerto Rico and US Virgin Islands, in the Greater and Lesser Antilles, and along the Central American mainland down to Brazil. Nesting occurs in Mexico, Costa Rica, and remote islands around Australia and in the Indian Ocean. Adult hawksbills live almost exclusively around coral reefs, except on the Pacific side of Central America, where they frequent the waters beneath mangroves.
Kemp's Ridley (Lepidochelys kempii)
IUCN critically endangered
US ESA endangered
The rarest and most endangered sea turtle, Kemp's ridleys are also the smallest at 85 to 100 pounds and 2.0 to 2.5 feet long. They eat crabs and other crustaceans, fish, jellyfish, and mollusks. This species lives throughout the Gulf of Mexico and along the US Atlantic seaboard from Florida to New England and occasionally shows up in the eastern Atlantic around the Azores, Morocco, and in the Mediterranean. Kemp's ridleys nest April through July in arribadas on one primary nesting beach in the northern Mexican state of Tamaulipas. An arribada of more than 40,000 ridleys was filmed in 1947, but between 1978 and 1991, only about 200 nests were recorded each year. Thanks to protection efforts, the number of nests had increased to more than 12,000 in 2006. An extensive effort also restored nesting on the Texas coast, mostly at Padre Island National Seashore, where several hundred nests have been recorded in recent years.
Flatback (Natator depressus)
IUCN not yet assessed, considered "vulnerable" by Australia and state of Queensland
This species, characterized by a flattened, olive-gray shell, lives only in the tropical waters of Australia and nests on remote beaches so is the least-known sea turtle. In fact, during the past few centuries, it had several names and was only formally declared a unique species in the 1980s. Adults weigh 150 to 200 pounds with a shell from 30 to 39 inches long, and they feed on jellyfish and other soft-bodied, bottom-dwelling invertebrates. The front flippers are short and smaller than those of other sea turtles about the same size.
Flatbacks appear to be abundant throughout Australian coastal waters and into the Sea of Indonesia and Gulf of Papua. Apparently, they rarely venture into deep water. Most nesting activity occurs across the northern coast of the continent, with females laying fewer but generally larger eggs than those of other sea turtle species. Nesting seasons vary from one location to another. Hatching success rate seems high, although predators such as lizards, birds, and crabs do kill hatchlings. Introduced red foxes, feral dogs, and dingos also raid nests. The Australian government protects nesting beaches and, in two of the country's largest fisheries, requires the use of special devices that allow sea turtles to escape from fishing nets.
The Nesting Experience
As you will see throughout this book, turtle walks and nest watches start once a mother sea turtle has dug a nest chamber in the sand and begun laying her eggs. Because nesting sea turtles fall into an almost trance-like state while laying their eggs, observers can get fairly close without disturbing a nesting turtle and watch the round, glistening orbs drop into the dark cavity she created in the sand. Sea turtles may lay from 80 to 120 eggs per nest. Once she is finished, the mother turtle uses her back flippers to cover the eggs with sand, then rocks her body around on the top of the nest and tosses sand with her front flippers to disguise her work. Finally, she makes a slow, labored crawl back to the water. The entire nesting process takes about 45 minutes, but the total length of a turtle walk experience usually depends on how long it takes to locate a nesting female.
Threats to Sea Turtles
Through their exceedingly long history on earth, sea turtles have encountered many obstacles to survival—ice ages, severe storms, an extraordinary array of predators, and cataclysmic events that wiped out the dinosaurs. Yet they survived and thrived.
Until humans came along. Of course, a few indigenous people eating sea turtle meat or eggs, or catching the occasional turtle by accident on a fishing line, likely made scarcely a dent in their numbers. But as more and more people occupied the planet, that changed. Before long, sea turtle reproduction could not keep up with the rate at which humans consumed their meat and eggs. Industrial fishing efforts in much of the world's oceans began killing them in larger and larger numbers. At the same time, pollution of the ocean and beaches affected sea turtle health and survival. Nesting females encountered coastal development and obstacles on more and more beaches.
Today, sea turtles enjoy protection in many parts of the world, and the diligent efforts of scientists, conservationists, and the public have removed some of the threats to their survival. The number of sea turtles and nests have rebounded in places. The battle is far from over though. Sea turtles still face a number of daunting threats.
Fishing Activity
Our seemingly insatiable demand for inexpensive seafood represents one of the biggest threats to sea turtles. They and other wildlife are caught in trawl nets that drag behind boats for hours at a time, or on underwater hooks set on longlines, and are injured or drown. Up to a quarter of a million sea turtles get caught on hooks or ensnared in fishing lines each year, and at one time an estimated 11,000 sea turtles drowned in shrimp nets each year. That last figure decreased significantly after the United States began requiring that shrimp boats use turtle excluder devices (TEDs), a grid of bars over a flap in the net that keeps sea turtles and other larger creatures out but shrimp in. TEDs are inexpensive and effective in saving turtles about 97 percent of the time. They also reduce the bycatch of other species and, by reducing drag from larger animals in the nets, can reduce fuel consumption. The National Oceanic and Atmospheric Administration (NOAA), through its National Marine Fisheries Service, phased in requirements for shrimp boats to use TEDs and has conducted numerous workshops on their use. NOAA also has worked with other countries to develop TED programs. However, compliance remains spotty, which is a cause for concern. In recent years, for example, necropsies (animal autopsies) performed on sea turtles washed up dead on Gulf of Mexico beaches during shrimp season have revealed evidence that the turtles drowned in shrimp nets.
Most shrimp—the number-one seafood consumed in the United States—now come from farms, which often displace natural mangrove habitat and introduce chemicals into the water. If you buy shrimp, ask the seller whether it came from a farm or was wild caught, and if the latter, whether a TED was in use. If it came from a foreign shrimp farm, or was caught without the use of a TED, or if the seller does not know, do not make the purchase, and be sure the seller knows why. Let your state and federal representatives know that you support regulations that require the use of TEDs.
As many as 1.4 billion hooks may go into the oceans each year on longlines stretching for miles. Circle hooks reduce the number of sea turtles caught on these fishing lines. Circle hooks are similar to the J-shaped hooks in common use but are larger, and the hook portion points inward so that it looks like a capital G. This shape takes advantage of the different ways fish and sea turtles feed, making the hooks less likely to pierce a turtle's jaw. Special dehooking devices have been developed that make it easier for commercial or recreational fishers to punch a hook back out of the same hole it entered, minimizing the injury of releasing the animal.
If you go fishing, do not cast lines or set nets near turtles. If you hook or entangle a sea turtle, gently bring it close to you and lift it by its front flipper and shell, not by the hook or net. Cut the line to the hook and remove excess line, but do not remove the hook unless it is lightly set and you are certain you can do so without injuring the turtle. Keep the turtle in the shade and call local wildlife authorities, even if the turtle appears fine. It may have ingested other hooks, which will need to be removed. Never dispose of hooks and line overboard, and never place your anchor on coral or seagrass beds.
(Continues...)
Excerpted from A Worldwide Travel Guide to Sea Turtles by Wallace J. Nichols, Brad Nahill, Melissa Gaskill. Copyright © 2014 Wallace J. Nichols, Brad Nahill, and Melissa Gaskill. Excerpted by permission of Texas A&M University Press.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
Contents
PREFACE,SEA TURTLES AND THE THREATS TO THEIR SURVIVAL,
Sea Turtle Species,
The Nesting Experience,
Threats to Sea Turtles,
A WORLDWIDE TRAVEL GUIDE TO SEA TURTLES,
United States,
California and the West Coast,
Florida,
Georgia,
Hawaii,
North Carolina,
South Carolina,
Texas,
Caribbean Islands,
Cayman Islands Sea Turtle Farming,
Cuba,
Dominica,
Grenada,
Puerto Rico,
St. Eustatius,
Trinidad and Tobago,
US Virgin Islands,
St Croix, Jack of Issac's Bay Preserve,
Mexico,
Baja California Sur,
Colima,
Guerrero,
Oaxaca,
Quintana Roo,
Central America,
Costa Rica,
El Salvador,
Guatemala,
Nicaragua,
Panama,
South America,
Brazil,
Uruguay,
Mediterranean Sea,
Mediterranean Association to Save the Sea Turtles, Athens,
The Sea Turtle Protection Society of Greece, Zakynthos,
Africa,
Cape Verde,
Gabon,
Ghana,
Kenya, Watamu Turtle Program,
Mozambique,
South Africa,
Indian Ocean,
India,
Oman,
South Pacific,
National Park of American Samoa/National Marine Sanctuary of American Samoa,
Australia,
Commonwealth of the Northern Mariana Islands,
Indonesia,
Ulithi Sea Turtle Project, Micronesia,
Samoa,
Arnavons Community Marine Conservation Area, Solomon Islands,
CAPTIVE ENCOUNTERS,
Reef HQ Aquarium, Australia,
Neotropical Foundation, Tenerife, Canary Islands,
Xcaret, Quintana Roo, Mexico,
South Africa,
United States,
RESOURCES AND ORGANIZATIONS,
INDEX,
Interviews
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