Sea Turtles in the Classroom: A Model for Science Education Presented by Karen M. Klein, M.S., Ph.D. student Karen M. Klein, M.S., Ph.D. student Drexel.

Sea Turtles in the Sea Turtles in the Classroom: A Model for Classroom: A Model for

Science EducationScience Education

Presented byPresented by Karen M. Klein, M.S., Ph.D. studentKaren M. Klein, M.S., Ph.D. student

Drexel University, Philadelphia, PA USADrexel University, Philadelphia, PA USA

Drexel UniversityDrexel University

Study turtles in the city, you ask?!?Study turtles in the city, you ask?!?

Drexel UniversityDrexel University

Drexel University is home of the Center for Biodiversity Drexel University is home of the Center for Biodiversity and Conservationand Conservation

Graduate students from the United States and the Graduate students from the United States and the world are doing research in areas all over the globeworld are doing research in areas all over the globe

Drexel UniversityDrexel University Professors at Drexel’s Center for Professors at Drexel’s Center for

Biodiversity and Conservation have Biodiversity and Conservation have decades of years of experience and decades of years of experience and hundreds of publications in the field of hundreds of publications in the field of turtle biology, ecology, and conservation!turtle biology, ecology, and conservation!

Current ResearchCurrent Research

The Leatherback Trust, founded in 1988 by Drexel The Leatherback Trust, founded in 1988 by Drexel University professor Dr. James Spotila, currently has University professor Dr. James Spotila, currently has an active leatherback sea turtle conservation and an active leatherback sea turtle conservation and education program in Las Baulas, Costa Ricaeducation program in Las Baulas, Costa Rica


Drexel students, as well as students from other Drexel students, as well as students from other Universities and Earthwatch volunteers, carry out an Universities and Earthwatch volunteers, carry out an extensive research program on Costa Rica’s population extensive research program on Costa Rica’s population of Leatherback sea turtles of Leatherback sea turtles

These efforts include movement studies, nesting These efforts include movement studies, nesting studies, and hatchling studiesstudies, and hatchling studies


Research on turtles in not confined Research on turtles in not confined to marine turtles, howeverto marine turtles, however


Dr. Hal Avery and his graduate students have been Dr. Hal Avery and his graduate students have been conducting a long term population study of the conducting a long term population study of the threatened desert tortoise, threatened desert tortoise, Gopherus agassiziiGopherus agassizii, in the , in the Mojave desertMojave desert


Barbara Bell has dedicated her doctoral research to Barbara Bell has dedicated her doctoral research to studying the effects of a recent oil spill on hatchling and studying the effects of a recent oil spill on hatchling and adult snapping turtles (adult snapping turtles (Chelydra serpentinaChelydra serpentina) in the ) in the John Heinz Refuge in PhiladelphiaJohn Heinz Refuge in Philadelphia


Amanda Curtin has devoted her doctoral Amanda Curtin has devoted her doctoral research to a osteological growth study of the research to a osteological growth study of the desert tortoisedesert tortoise


Karen Klein and Bibi Tomillo, both doctoral students, Karen Klein and Bibi Tomillo, both doctoral students, are conducting a population biology study of red-bellied are conducting a population biology study of red-bellied turtles (turtles (Pseudemys rubriventrisPseudemys rubriventris) in the wetland areas ) in the wetland areas within the Philadelphia Airportwithin the Philadelphia Airport


A large project run by Dr. Walt Bien at Warren A large project run by Dr. Walt Bien at Warren Grove Range in the Pine Barrens, NJ includes Grove Range in the Pine Barrens, NJ includes research with population and conservation research with population and conservation studies of mammals, reptiles, plant species, studies of mammals, reptiles, plant species, and fire ecology and fire ecology

IntroductionIntroduction

Of all animals, the humble turtle seems to Of all animals, the humble turtle seems to capture the imagination and wonder of children capture the imagination and wonder of children of all ages the mostof all ages the most


Turtles have found themselves a part of Turtles have found themselves a part of popular culture popular culture

Who can forget Yertle and the Art of Turtle Who can forget Yertle and the Art of Turtle Stacking??Stacking??


Even as adults, most of us remain fascinated Even as adults, most of us remain fascinated by these animalsby these animals

Their protective shells are of curiosity and their Their protective shells are of curiosity and their ancient-like demeanor make them especially ancient-like demeanor make them especially endearingendearing


In a recent poll of freshman Biology students In a recent poll of freshman Biology students (non majors), 95% of them said they think (non majors), 95% of them said they think turtles are very interesting animalsturtles are very interesting animals

The fascination with turtles transcends all The fascination with turtles transcends all ages, backgrounds and culturesages, backgrounds and cultures


Whether revered as a cultural and spiritual icon Whether revered as a cultural and spiritual icon or just thought to be “cool”...or just thought to be “cool”...

Just about everybody likes turtles!!!Just about everybody likes turtles!!!

IntroductionIntroduction This interest in the organism itself can be used This interest in the organism itself can be used

as an advantage to today’s classroom educatoras an advantage to today’s classroom educator Turtles, like many animals, are an important Turtles, like many animals, are an important

part of our ecosystem, and are greatly affected part of our ecosystem, and are greatly affected by current issues like habitat loss and pollutionby current issues like habitat loss and pollution

In this way, turtles can be incorporated into In this way, turtles can be incorporated into many concepts in science, and therefore be many concepts in science, and therefore be used as a tool to fulfill your New Jersey Core used as a tool to fulfill your New Jersey Core Curriculum Content Standards for scienceCurriculum Content Standards for science


Sea turtles are ancient creatures. They have traveled Sea turtles are ancient creatures. They have traveled our planet for more than 200 million years, tracing a our planet for more than 200 million years, tracing a highly successful evolutionary path, living in a variety of highly successful evolutionary path, living in a variety of environments from dry land to the open sea. This environments from dry land to the open sea. This makes them fascinating, albeit tough, subjects to study. makes them fascinating, albeit tough, subjects to study.


Of the 16 Orders of reptiles that evolved during the last Of the 16 Orders of reptiles that evolved during the last 310 million years, that of the Testudines, or turtles, is 310 million years, that of the Testudines, or turtles, is one of only four that remain today one of only four that remain today

The three other Orders are Crocodilia, Squamata, and The three other Orders are Crocodilia, Squamata, and Rhyncocephala (Tuataras).Rhyncocephala (Tuataras).


Turtles are distinctive because they live inside shells Turtles are distinctive because they live inside shells The top shell, over the back, is called the "carapace", The top shell, over the back, is called the "carapace",

and the shell on the bottom, over the belly, is called the and the shell on the bottom, over the belly, is called the "plastron"plastron

In most turtles, the shell is made up of large bones, In most turtles, the shell is made up of large bones, covered on the outside by large scales, known as covered on the outside by large scales, known as "scutes". "scutes".


Turtles, terrapins and tortoises all belong to the Turtles, terrapins and tortoises all belong to the Order Testudinata (also called Chelonia)Order Testudinata (also called Chelonia)

Of the more than 220 species of living turtles, Of the more than 220 species of living turtles, only 7 are marine only 7 are marine

Sea Turtles of the WorldSea Turtles of the World

Loggerhead (Loggerhead (Caretta Caretta caretta)caretta)

Characteristics:Characteristics: Named for its very large head and strong Named for its very large head and strong jaws; 32-41 inches long, up to 350 lbsjaws; 32-41 inches long, up to 350 lbs

Diet:Diet: primarily carnivorous, feeding on shellfish at the bottom of primarily carnivorous, feeding on shellfish at the bottom of the oceanthe ocean

HabitatHabitat: Prefer to feed in coastal bays and estuaries, as well as : Prefer to feed in coastal bays and estuaries, as well as in the shallow water along the continental shelves of the in the shallow water along the continental shelves of the Atlantic, Pacific and Indian OceansAtlantic, Pacific and Indian Oceans

LoggerheadLoggerhead

Range:Range: worldwide worldwide Status: U.S.Status: U.S. - Listed as Threatened; - Listed as Threatened; InternationalInternational - Listed as - Listed as

Endangered Endangered Nesting:Nesting: Nest at intervals of 2, 3, or more years. Nests Nest at intervals of 2, 3, or more years. Nests

between 4 to 7 times per season. Lays average of between between 4 to 7 times per season. Lays average of between 100 to 126 eggs in each nest. 100 to 126 eggs in each nest.

Green turtle (Green turtle (Chelonia mydasChelonia mydas))

CharacteristicsCharacteristics: Head is small; The carapace color : Head is small; The carapace color varies from pale to very dark green and plain to very varies from pale to very dark green and plain to very brilliant yellow; 3 feet in length, about 300-350 lbs brilliant yellow; 3 feet in length, about 300-350 lbs

Diet:Diet: mostly eat sea grass and algae, the only sea turtle mostly eat sea grass and algae, the only sea turtle that is strictly herbivorous as an adultthat is strictly herbivorous as an adult

HabitatHabitat: Mainly stay near the coastline and around : Mainly stay near the coastline and around islands and live in bays and protected shores. Rarely are islands and live in bays and protected shores. Rarely are they observed in the open ocean they observed in the open ocean

Range:Range: Found in all temperate and tropical waters throughout the Found in all temperate and tropical waters throughout the world.world.Status:Status: U.S.U.S. - Listed as Endangered; - Listed as Endangered; InternationalInternational - Listed as - Listed as EndangeredEndangered

Nesting:Nesting: Nest at intervals of 2, 3, or more years; Nests between 3 Nest at intervals of 2, 3, or more years; Nests between 3 to 5 times per season; Lays an average of 115 eggs in each nest; to 5 times per season; Lays an average of 115 eggs in each nest; largest nesting site in Western hemisphere: Tortugeuro, Costa Ricalargest nesting site in Western hemisphere: Tortugeuro, Costa Rica

Leatherback (Leatherback (Dermochelys coriaceaDermochelys coriacea))

Characteristics: Characteristics: Carapace is large, elongated and flexible with 7 distinct ridges Carapace is large, elongated and flexible with 7 distinct ridges running the length of the animal; composed of a layer of thin, tough, rubbery skin; running the length of the animal; composed of a layer of thin, tough, rubbery skin; to 8 feet in carapace length; 450 to 1,300 poundsto 8 feet in carapace length; 450 to 1,300 pounds

Diet:Diet: Feed almost exclusively on jellyfish Feed almost exclusively on jellyfish Habitat:Habitat: Primarily found in the open ocean, as far north as Alaska and as far Primarily found in the open ocean, as far north as Alaska and as far

south as the southern tip of Africa. Known to be active in water below 40 degrees south as the southern tip of Africa. Known to be active in water below 40 degrees Fahrenheit, the only reptile known to remain active at such a low temperature.Fahrenheit, the only reptile known to remain active at such a low temperature.

Range:Range: Most widely distributed of all sea turtles; found world wide Most widely distributed of all sea turtles; found world wide with the largest north and south range of all the sea turtle specieswith the largest north and south range of all the sea turtle species

Status: U.S.Status: U.S. - Listed as Endangered; - Listed as Endangered; InternationalInternational - Listed as - Listed as Critically EndangeredCritically Endangered

Nesting:Nesting: Nest at intervals of 2 to 3 years. Nests between 6 to 9 Nest at intervals of 2 to 3 years. Nests between 6 to 9 times per season. Lays an average of 80 fertilized eggstimes per season. Lays an average of 80 fertilized eggs

Flatback (Flatback (Natator depressaNatator depressa))

Characteristics:Characteristics: Carapace is oval or round and body is very flat; carapace is Carapace is oval or round and body is very flat; carapace is olive-grey with pale brown/yellow tones on margins and the flippers creamy olive-grey with pale brown/yellow tones on margins and the flippers creamy white; up to 39 inches in carapace length; average of 198 poundswhite; up to 39 inches in carapace length; average of 198 pounds

Diet:Diet: Apparently eats sea cucumbers, jellyfish, mollusks, prawns, bryozoans, Apparently eats sea cucumbers, jellyfish, mollusks, prawns, bryozoans, other invertebrates and seaweedother invertebrates and seaweed

Habitat:Habitat: Prefer turbid inshore waters, bays, coastal coral reef and grassy Prefer turbid inshore waters, bays, coastal coral reef and grassy shallowsshallows

Range:Range: Most restricted range of all sea turtle species, Most restricted range of all sea turtle species, limited to the coastal waters of the northwestern, northern limited to the coastal waters of the northwestern, northern and northeastern regions of Australia and the Gulf of Papua, and northeastern regions of Australia and the Gulf of Papua, New GuineaNew Guinea

Status: Status: Listed as Data Deficient Listed as Data Deficient Nesting:Nesting: Nests 4 times per season. Lays an average of 50 Nests 4 times per season. Lays an average of 50

eggs in each nest eggs in each nest

Hawksbill (Hawksbill (Eretmochelys imbricataEretmochelys imbricata))

Characteristics:Characteristics: Head is narrow, carapace is elliptical, orange, Head is narrow, carapace is elliptical, orange, brown or yellow; 30 to 36 inches in carapace long; 100 to 150 brown or yellow; 30 to 36 inches in carapace long; 100 to 150 poundspounds

Diet:Diet: The hawksbill's narrow head and jaws shaped like a beak The hawksbill's narrow head and jaws shaped like a beak allow it to get food from crevices in coral reefs. They eat sponges, allow it to get food from crevices in coral reefs. They eat sponges, anemones, squid and shrimpanemones, squid and shrimp

Habitat:Habitat: Typically found around coastal reefs, rocky areas, Typically found around coastal reefs, rocky areas, estuaries and lagoons estuaries and lagoons

Range:Range: Most tropical of all sea turtles. Tropical and subtropical Most tropical of all sea turtles. Tropical and subtropical waters of the Atlantic, Pacific and Indian Oceanswaters of the Atlantic, Pacific and Indian Oceans

Status: U.S.Status: U.S. - Listed as Endangered; - Listed as Endangered; InternationalInternational - Listed as - Listed as Critically EndangeredCritically Endangered

Nesting:Nesting: Nest at intervals of 2, 3, or more years. Nests between 2 Nest at intervals of 2, 3, or more years. Nests between 2 to 4 times per season. Lays an average 160 eggs in each nestto 4 times per season. Lays an average 160 eggs in each nest

Kemp’s ridley (Kemp’s ridley (Lepidochelys Lepidochelys kempiikempii))

Characteristics:Characteristics: Head is moderate and triangular in size; adults Head is moderate and triangular in size; adults have a dark grey green carapace with a white or yellowish have a dark grey green carapace with a white or yellowish plastron; adults measure 24 to 28 inches; between 77 and 100 plastron; adults measure 24 to 28 inches; between 77 and 100 poundspounds

Diet:Diet: Have powerful jaws that help them to crush and grind crabs, Have powerful jaws that help them to crush and grind crabs, calms, mussels, and shrimp. They also like to eat fish, sea calms, mussels, and shrimp. They also like to eat fish, sea urchins, squid and jellyfishurchins, squid and jellyfish

Habitat:Habitat: Prefer shallow areas with sandy and muddy bottoms. Prefer shallow areas with sandy and muddy bottoms.

Range:Range: Adults are mostly limited to the Gulf of Mexico Adults are mostly limited to the Gulf of Mexico Status: U.S.Status: U.S. - Listed as Endangered; - Listed as Endangered; InternationalInternational - -

Listed as Critically EndangeredListed as Critically Endangered Nesting:Nesting: Nest every year in arribadas. Nests about 2 Nest every year in arribadas. Nests about 2

times each season. Lays an average of 110 eggs in times each season. Lays an average of 110 eggs in each nest each nest

Olive Ridley (Olive Ridley (Lepidochelys Lepidochelys olivaceaolivacea))

Characteristics:Characteristics: Head is quite small; named for its olive green colored Head is quite small; named for its olive green colored shell; Adults measure 24 to 28 inches; between 77 and 100 poundsshell; Adults measure 24 to 28 inches; between 77 and 100 pounds

Diet:Diet: Have powerful jaws that help them to crush and grind crabs, Have powerful jaws that help them to crush and grind crabs, clams, mussels, and shrimp. They also like to eat fish, sea urchins, clams, mussels, and shrimp. They also like to eat fish, sea urchins, squid and jellyfishsquid and jellyfish

Habitat:Habitat: They typically forage off shore in surface waters or dive to They typically forage off shore in surface waters or dive to depths of 500 feet (150 m) to feed on bottom dwelling crustaceans. depths of 500 feet (150 m) to feed on bottom dwelling crustaceans.

Range:Range: Live in tropical regions of the Pacific, Indian and Atlantic Oceans Live in tropical regions of the Pacific, Indian and Atlantic Oceans Status: U.S.Status: U.S. - Listed as Threatened; - Listed as Threatened; InternationalInternational - Listed as - Listed as

EndangeredEndangered Nesting:Nesting: Nest every year in arribadas. Nests 2 times each season. Lays Nest every year in arribadas. Nests 2 times each season. Lays

an average of over 105 eggs in each nest an average of over 105 eggs in each nest

Distribution and HabitatDistribution and Habitat

Sea turtles live inhabit all of the world’s oceansSea turtles live inhabit all of the world’s oceans Adults of most species are found in shallow, Adults of most species are found in shallow,

coastal waters, bays, lagoons, and estuaries. coastal waters, bays, lagoons, and estuaries. Some also venture into the open sea. Some also venture into the open sea.

MigrationMigration

Some sea turtle populations nest and feed in the same Some sea turtle populations nest and feed in the same general areas; others migrate great distances.general areas; others migrate great distances.

Migration habits differ among sea turtle species; Migration habits differ among sea turtle species; migrations may range from a few to thousands of migrations may range from a few to thousands of miles. miles.

MigrationMigration

Green sea turtle populations migrate primarily along Green sea turtle populations migrate primarily along the coasts from nesting to feeding groundsthe coasts from nesting to feeding grounds

Some populations will travel 1,300 miles across the Some populations will travel 1,300 miles across the Atlantic Ocean from the Ascension Island nesting Atlantic Ocean from the Ascension Island nesting grounds to the Brazilian coast feeding grounds grounds to the Brazilian coast feeding grounds

MigrationMigration

Loggerheads leave foraging areas and travel on Loggerheads leave foraging areas and travel on

breeding migrations that range from a few to breeding migrations that range from a few to thousands of milesthousands of miles

MigrationMigration

Leatherbacks have the longest migration of all Leatherbacks have the longest migration of all sea turtles. They have been found more than sea turtles. They have been found more than 4,831 km (3,000 miles) from their nesting 4,831 km (3,000 miles) from their nesting beaches beaches

PopulationPopulation Total population figures are often difficult to Total population figures are often difficult to

ascertain because juvenile and male sea ascertain because juvenile and male sea turtles do not come ashore and are difficult to turtles do not come ashore and are difficult to count. count.

Population data are usually based on the Population data are usually based on the numbers of adult females that come ashore to numbers of adult females that come ashore to nest. Even then, the numbers are ambiguous - nest. Even then, the numbers are ambiguous - some females nest every two to three years, some females nest every two to three years, some may nest more than once on the same some may nest more than once on the same beach in a season, and some females will visit beach in a season, and some females will visit more than one nesting beach in a season. more than one nesting beach in a season.

PopulationPopulation

The Kemp's ridley is the most endangered sea turtleThe Kemp's ridley is the most endangered sea turtle In 1947, 92,000 nests were estimated. Surveys In 1947, 92,000 nests were estimated. Surveys

conducted between 1978 and 1988 indicated an conducted between 1978 and 1988 indicated an average of about 800 nests per yearaverage of about 800 nests per year

The total number of nesting females may be as low as The total number of nesting females may be as low as 350 on beaches where tens of thousands of Kemp's 350 on beaches where tens of thousands of Kemp's ridley used to nest ridley used to nest

PopulationPopulation

U.S. population trends of loggerheads show a U.S. population trends of loggerheads show a decline in nesting areas of Georgia and South decline in nesting areas of Georgia and South CarolinaCarolina

No decline or a possible increase in southern No decline or a possible increase in southern Florida Atlantic areas. Florida Atlantic areas.

SizeSize

The Kemp's ridley is the smallest species, and reach about 22-30 The Kemp's ridley is the smallest species, and reach about 22-30 in and 66-110 lbin and 66-110 lb

The leatherback is the largest of all living sea turtles. Mature The leatherback is the largest of all living sea turtles. Mature leatherbacks reach about 4-6 ft. and 441-1,116 lbs The largest leatherbacks reach about 4-6 ft. and 441-1,116 lbs The largest leatherback recorded was 2,019 lbs. leatherback recorded was 2,019 lbs.

FlippersFlippers

Flippers are adapted for swimming; sea turtles are awkward and Flippers are adapted for swimming; sea turtles are awkward and vulnerable on land. vulnerable on land.

Foreflippers are long and paddle-like, swimming with powerful Foreflippers are long and paddle-like, swimming with powerful wing-like beatswing-like beats

Hind flippers serve as rudders, stabilizing and directing the animal Hind flippers serve as rudders, stabilizing and directing the animal as it swims. The hind flippers of some species are quite dexterous as it swims. The hind flippers of some species are quite dexterous in digging nests in the sand. in digging nests in the sand.

Head and jawHead and jaw

A sea turtle cannot retract its head under its shell as a A sea turtle cannot retract its head under its shell as a land turtle can. land turtle can.

Like other turtles, sea turtles lack teeth. Jaw shape Like other turtles, sea turtles lack teeth. Jaw shape varies among species. Each species has a jaw shape varies among species. Each species has a jaw shape adapted for its dietadapted for its diet

Head and jawHead and jaw

The jaw structure of many species indicates The jaw structure of many species indicates their diet their diet

ShellShell

The large, bony shell provides protection from The large, bony shell provides protection from predation and abrasion predation and abrasion Depending on species, the adult carapace ranges in Depending on species, the adult carapace ranges in shape from oval to heart-shaped; this allows the turtle shape from oval to heart-shaped; this allows the turtle to be streamlined as it swims through the water to be streamlined as it swims through the water

ShellShell

In all species except the leatherback, the shell is In all species except the leatherback, the shell is covered with a layer of horny plates called scutescovered with a layer of horny plates called scutes

The leatherback turtle has a thick and oil-suffused skin, The leatherback turtle has a thick and oil-suffused skin, which is an excellent insulator allowing this species to which is an excellent insulator allowing this species to venture into colder watersventure into colder waters

DivingDiving

Sea turtles are excellent divers. Leatherbacks routinely Sea turtles are excellent divers. Leatherbacks routinely dive more than 1,000 ft., and they may reach depths of dive more than 1,000 ft., and they may reach depths of more than 3,900 ft. seeking jellyfish more than 3,900 ft. seeking jellyfish

Hawksbill turtles have been known to remain Hawksbill turtles have been known to remain submerged for 35 to 45 minutes; green sea turtles can submerged for 35 to 45 minutes; green sea turtles can stay under water for as long as five hoursstay under water for as long as five hours

Sexual MaturitySexual Maturity

Estimates of sexual maturity in sea turtles vary not only Estimates of sexual maturity in sea turtles vary not only among species, but also among different populations of among species, but also among different populations of the same speciesthe same species

Maturity may range from as early as three years in Maturity may range from as early as three years in hawksbills; 12 to 30 years in loggerheads; to 20 to 50 hawksbills; 12 to 30 years in loggerheads; to 20 to 50 years in green sea turtlesyears in green sea turtles

Mating ActivityMating Activity

For most species, courtship activity usually occurs For most species, courtship activity usually occurs several weeks before the nesting season several weeks before the nesting season

Males have enlarged claws on their front flippers. Males have enlarged claws on their front flippers. These aid males in grasping the shells of the females These aid males in grasping the shells of the females during mating during mating

Fertilization is internal. Copulation takes place in the Fertilization is internal. Copulation takes place in the water, just offshorewater, just offshore

Nesting behaviorNesting behavior

Like other turtles, sea turtles lay eggs; they must come Like other turtles, sea turtles lay eggs; they must come ashore to do so ashore to do so

Females usually nest during the warmest months of the Females usually nest during the warmest months of the year. The exception is the leatherback turtle, which year. The exception is the leatherback turtle, which nests in fall and winter nests in fall and winter

Most females return to the same nesting beach each Most females return to the same nesting beach each yearyear


Females of most species usually come ashore at night, Females of most species usually come ashore at night, alone, most often during high tidealone, most often during high tide

A female sea turtle crawls above the high tide line and, A female sea turtle crawls above the high tide line and, using her front flippers, digs out a "body pit" using her front flippers, digs out a "body pit"

Then using her hind flippers, she digs an egg cavity. Then using her hind flippers, she digs an egg cavity. The depth of the cavity is determined by the length of The depth of the cavity is determined by the length of the stretched hind flipper the stretched hind flipper


Depending on the species, the female deposits 50 to Depending on the species, the female deposits 50 to 200 Ping Pong ball-shaped eggs into the egg cavity200 Ping Pong ball-shaped eggs into the egg cavity

The eggs are soft-shelled, and are papery to leathery The eggs are soft-shelled, and are papery to leathery in texture. They do not break when they fall into the in texture. They do not break when they fall into the egg cavity. The eggs are surrounded by a thick, clear egg cavity. The eggs are surrounded by a thick, clear mucusmucus

Nesting behaviorNesting behavior The female covers the nest with sand using her The female covers the nest with sand using her

hind flippers. Burying the eggs serves three hind flippers. Burying the eggs serves three purposes: it helps protect the eggs from purposes: it helps protect the eggs from surface predators; it helps keep the soft, surface predators; it helps keep the soft, porous shells moist, thus protecting them from porous shells moist, thus protecting them from drying out; and it helps the eggs maintain drying out; and it helps the eggs maintain proper temperatureproper temperature

Females may spend two or more hours out of Females may spend two or more hours out of the water during the entire nesting process the water during the entire nesting process

Nesting behaviorNesting behavior Females usually lay Females usually lay

between one and between one and nine nine clutchesclutches (groups) of eggs per (groups) of eggs per season season

Females may nest Females may nest every two to three every two to three yearsyears

Nesting behaviorNesting behavior The Kemp's ridley and The Kemp's ridley and

olive ridley form masses olive ridley form masses called called arribadas arribadas (Spanish for "arrival")(Spanish for "arrival")

Arribadas contain Arribadas contain thousands of egg-thousands of egg-bearing females that bearing females that come ashore at the come ashore at the same time to lay eggs same time to lay eggs

IncubationIncubation The incubation time for most species is The incubation time for most species is

45 to 70 days 45 to 70 days Research indicates that the sex of an Research indicates that the sex of an

embryo is determined sometime after embryo is determined sometime after fertilization, as the embryo develops, and fertilization, as the embryo develops, and may be temperature dependent. Lower may be temperature dependent. Lower nest temperatures produce more males; nest temperatures produce more males; higher temperatures produce more higher temperatures produce more females females

HatchingHatching

Hatchlings use a Hatchlings use a carunclecaruncle (temporary egg tooth) to (temporary egg tooth) to help break open the shell help break open the shell

After hatching, the young turtles may take three to After hatching, the young turtles may take three to seven days to dig their way to the surface. The time seven days to dig their way to the surface. The time immediately before emergence is referred to as a “boil”immediately before emergence is referred to as a “boil”

HatchingHatching

Hatchlings usually wait until night to emerge from the Hatchlings usually wait until night to emerge from the nest. Emerging at night reduces exposure to daytime nest. Emerging at night reduces exposure to daytime predatorspredators

They leave the nest and head to the water in groups—They leave the nest and head to the water in groups—towards the brightest spot, the horizon over the ocean towards the brightest spot, the horizon over the ocean

HatchlingsHatchlings

When a hatchling reaches the surf, it dives into a wave When a hatchling reaches the surf, it dives into a wave and rides the undertow out to sea and rides the undertow out to sea

A "swim frenzy" of continuous swimming takes place A "swim frenzy" of continuous swimming takes place for about 24 to 48 hours after the hatchling enters the for about 24 to 48 hours after the hatchling enters the water water

HatchlingsHatchlings

During the first year, many species of sea During the first year, many species of sea turtles are rarely seen. This first year is known turtles are rarely seen. This first year is known as the "lost year" as the "lost year"

Most researchers believe that they ride Most researchers believe that they ride prevailing surface currents, situating prevailing surface currents, situating themselves in floating seaweed where they are themselves in floating seaweed where they are camouflaged and where they can find food camouflaged and where they can find food

LongevityLongevity

Once sea turtles reach sexual maturity, Once sea turtles reach sexual maturity, they may have an estimated reproductive they may have an estimated reproductive life of about 30 years life of about 30 years

Given that some species reach maturity Given that some species reach maturity at 50 years, an 80-year lifespan is at 50 years, an 80-year lifespan is feasible feasible

Threats to sea turtle Threats to sea turtle survivalsurvival

1. PREDATION1. PREDATION Adult sea turtles have few predators, mostly large Adult sea turtles have few predators, mostly large

sharkssharks Eggs and hatchlings are vulnerable to many predators. Eggs and hatchlings are vulnerable to many predators.

More than 90% of hatchlings are predatedMore than 90% of hatchlings are predated

ThreatsThreats

2. Fibropapillomas.2. Fibropapillomas. Green sea turtles are black sea turtles may develop Green sea turtles are black sea turtles may develop

lobed tumorlike growths (fiborpapillomas) on the skin. lobed tumorlike growths (fiborpapillomas) on the skin. These growths can result in reduced vision, obstruction These growths can result in reduced vision, obstruction of normal swimming and feeding, and increased of normal swimming and feeding, and increased susceptibility to secondary parasitism and infectionsusceptibility to secondary parasitism and infection

ThreatsThreats

3. BEACH DEVELOPMENT/DISTURBANCE3. BEACH DEVELOPMENT/DISTURBANCE Nesting areas are becoming scarce due to beach development Nesting areas are becoming scarce due to beach development

and disturbances and disturbances Nesting females and hatchlings are disturbed by the presence of Nesting females and hatchlings are disturbed by the presence of

trash on nesting beaches. If trash impedes its crawl up the beach, trash on nesting beaches. If trash impedes its crawl up the beach, a female returns to the sea instead of nesting. a female returns to the sea instead of nesting.

The noise and activity of people on the beach also may cause The noise and activity of people on the beach also may cause females to return to the sea instead of nesting. females to return to the sea instead of nesting.

ThreatsThreats Artificial lighting on beaches may misrepresent Artificial lighting on beaches may misrepresent

the time of day to turtles attempting to nest. the time of day to turtles attempting to nest. Most turtles are nocturnal nesters, and to a Most turtles are nocturnal nesters, and to a turtle that has not yet come ashore to nest, a turtle that has not yet come ashore to nest, a brightly lighted beach may signify daylight and brightly lighted beach may signify daylight and inhibit nesting. inhibit nesting.

Hatchlings can become disoriented by city and Hatchlings can become disoriented by city and street lights when trying to find the surf. Many street lights when trying to find the surf. Many young turtles actually head away from the young turtles actually head away from the ocean and toward parking lots. These animals ocean and toward parking lots. These animals may be eaten by predators or crushed by cars. may be eaten by predators or crushed by cars. Some die from exposure. Some die from exposure.

ThreatsThreats 4. Pollution4. Pollution Some sea turtles die Some sea turtles die

when they ingest when they ingest trash. Leatherbacks trash. Leatherbacks are especially are especially susceptible to susceptible to ingesting plastic, ingesting plastic, mistaking it for mistaking it for jellyfish. jellyfish.

ThreatsThreats 5. Shrimp trawling5. Shrimp trawling netsnets Thousands of sea turtles Thousands of sea turtles

drown in shrimp nets drown in shrimp nets each year. Sea turtles each year. Sea turtles forage in waters where forage in waters where commercial shrimpers commercial shrimpers trawltrawl

Turtles get stuck in these Turtles get stuck in these nets and drown as a nets and drown as a resultresult

ThreatsThreats 6. Human predation6. Human predation Some people illegally collect Some people illegally collect

turtle eggs for food and for turtle eggs for food and for their alleged aphrodisiac their alleged aphrodisiac effect.effect.

Sea turtles are hunted for Sea turtles are hunted for their meat and shells, which their meat and shells, which are used to make combs, are used to make combs, eyeglass frames, eyeglass frames, aphrodisiacs, and curious. aphrodisiacs, and curious.

The fat of green sea turtles, The fat of green sea turtles, boiled with cartilage called boiled with cartilage called calipeecalipee, made a popular , made a popular soup, which led to the decline soup, which led to the decline in green sea turtle population in green sea turtle population numbers. numbers.

Conservation & Protection: Conservation & Protection: Legal protectionLegal protection

All eight species of sea turtles are listed as All eight species of sea turtles are listed as threatened or endangered on the U.S. threatened or endangered on the U.S. Endangered and Threatened Wildlife and Endangered and Threatened Wildlife and Plants List. It is illegal to harm, or in any way Plants List. It is illegal to harm, or in any way interfere with, a sea turtle or its eggs. interfere with, a sea turtle or its eggs.

The Convention on International Trade in The Convention on International Trade in Endangered Species of Wild Fauna and Flora Endangered Species of Wild Fauna and Flora (CITES) is an international treaty developed in (CITES) is an international treaty developed in 1973 to regulate trade in certain wildlife 1973 to regulate trade in certain wildlife species. CITES protects all species of sea species. CITES protects all species of sea turtles. The U.S. and 115 other countries have turtles. The U.S. and 115 other countries have banned the import or export of sea turtle banned the import or export of sea turtle productsproducts

Conservation & Conservation & Protection: TEDsProtection: TEDs

At a cost of millions of dollars, the National Marine Fisheries At a cost of millions of dollars, the National Marine Fisheries Service developed the Turtle Excluder Device (TED). Service developed the Turtle Excluder Device (TED).

The TED is a small, metal grid trapdoor inside a trawling net that The TED is a small, metal grid trapdoor inside a trawling net that allows shrimp to pass to the back while the turtles escape to safety allows shrimp to pass to the back while the turtles escape to safety before becoming entrapped or entangled.before becoming entrapped or entangled.

Since 1989, federal law requires that this device be installed on Since 1989, federal law requires that this device be installed on the nets of all U.S. fishing trawlers working in areas populated by the nets of all U.S. fishing trawlers working in areas populated by sea turtles. sea turtles.

Conservation & Protection: Conservation & Protection: Nest ProtectionNest Protection

Nests can be protected from predators by placing Nests can be protected from predators by placing screens over them. screens over them.

Eggs laid in high traffic beaches can be relocated to Eggs laid in high traffic beaches can be relocated to safer areas. safer areas.

Those nests left in place on beaches are marked for Those nests left in place on beaches are marked for beachgoers to avoid thembeachgoers to avoid them

Conservation & Protection: Conservation & Protection: Lighting OrdinancesLighting Ordinances

Reducing or Reducing or eliminating beach eliminating beach lighting on developed lighting on developed beaches during beaches during hatchling emergence hatchling emergence months prevent months prevent disorientation of disorientation of hatchlingshatchlings

Conservation and Conservation and Protection: Wildlife RefugesProtection: Wildlife Refuges Establishing Refuges on important Establishing Refuges on important

nesting beaches allows nesting sea nesting beaches allows nesting sea turtles and hatchlings protection from turtles and hatchlings protection from beach development beach development

Legislation is underway to allocate Legislation is underway to allocate government funding for the Archie Carr government funding for the Archie Carr National Wildlife Refuge on the east National Wildlife Refuge on the east coast of Florida, between Melbourne coast of Florida, between Melbourne Beach and Vero BeachBeach and Vero Beach

Conservation & Protection: Conservation & Protection: Wildlife RefugesWildlife Refuges

The governments of Nicaragua and Costa Rica The governments of Nicaragua and Costa Rica have established, and are striving to expand, have established, and are striving to expand, national parks and biological reserves where national parks and biological reserves where sea turtles forage and nest.sea turtles forage and nest.

Local economics is no longer based on turtle Local economics is no longer based on turtle harvests, but on tourismharvests, but on tourism

Conservation & Protection: Conservation & Protection: Wildlife RefugesWildlife Refuges

The Leatherback Trust has successfully The Leatherback Trust has successfully expanded Refuge property in Las Baulas, expanded Refuge property in Las Baulas, Costa Rica, in important leatherback turtle Costa Rica, in important leatherback turtle rookery. Dr. James Spotila of Drexel University rookery. Dr. James Spotila of Drexel University is the President of this organizationis the President of this organization

Conservation & Conservation & Protection: EducationProtection: Education

Education local communities and having sea turtles at Education local communities and having sea turtles at marine zoological parks provides an opportunity for the marine zoological parks provides an opportunity for the public to learn, up-close, about these animals and how public to learn, up-close, about these animals and how human activities may impact their survival. human activities may impact their survival.

Conservation & Conservation & Protection: ResearchProtection: Research

Researching sea turtles will allow us to better Researching sea turtles will allow us to better understand their biology and ecologyunderstand their biology and ecology

This will in turn allow ecologists to design This will in turn allow ecologists to design better and more effective conservation better and more effective conservation programsprograms

Conservation & Conservation & Protection: ResearchProtection: Research

Drexel University students are actively involved Drexel University students are actively involved in many research projects involving sea turtlesin many research projects involving sea turtles

The Leatherback Trust has been an important The Leatherback Trust has been an important force in conserving the leatherback turtle in force in conserving the leatherback turtle in Costa RicaCosta Rica

Sea Turtles in the Classroom: A Model for Science Education Presented by Karen M. Klein, M.S., Ph.D. student Karen M. Klein, M.S., Ph.D. student Drexel.

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