Implement this lesson:

Use this lesson when discussing animal ecosystems, habitats, or other environmental TEKs. This lesson can be used as part of a larger local theme i.e. Oceans Week. It can also be used for a sea turtle themed day. The duration of this lesson can vary based on student and teacher needs.

Learning Objective:

Students will be able to learn about one of the interesting animals found in local saltwater habitats, the seaturtle. They will create an art project using their knowledge.

Texas Essential Knowledge and Skills (TEKS)

Overview

There are seven recognized sea turtle species in the world, with five of them occurring in the Gulf. The Kemp’s Ridley sea turtle is a local success story in which thanks to efforts the species was brought back from the brink of extinction.

Kemp’s Ridley Sea Turtle (Lepidochelys kempii)

The Kemp’s ridley sea turtle is known for its small size, unique nesting behavior, and critically endangered status. It is found mainly in the Gulf of Mexico and along the Atlantic coast of North America.

Appearance and Behavior

• Adult size: 60–70 cm (2–2.5 feet) long
• Weight: 35–45 kg (77–100 lbs)
• Has a round, gray-green shell (carapace) and a pale yellowish belly
• Flippers are paddle-shaped for swimming
• Strong swimmers but spend most of their lives at sea

Diet and Feeding

• Eats mostly crabs, especially blue crabs, as well as shrimp, clams, jellyfish, and small fish
• Uses its strong beak-like mouth to crush hard-shelled prey
• Forages in shallow coastal waters, estuaries, and seagrass beds

Life Cycle and Reproduction

• Females nest mostly on beaches in Tamaulipas, Mexico, especially at Rancho Nuevo
• Famous for “arribadas”—mass nesting events where hundreds of females come ashore at once
• Nesting season: April to July
• Females lay about 100 eggs per nest and may nest 2–3 times per season
• Eggs incubate for about 50–60 days
• Hatchlings are about 4–5 cm (1.5–2 inches) long and head straight to the ocean
• Sexual maturity is reached at around 10–15 years of age

Habitat and Range

• Lives mostly in the Gulf of Mexico and along the U.S. Atlantic coast, from Florida to New England
• Spends most of its life in shallow, warm waters
• Nests almost exclusively on a few beaches in Mexico, with a smaller number in Texas, USA

Conservation Status

• Listed as Critically Endangered
• Threats include:
  • Egg poaching
  • Fishing gear entanglement (bycatch)
  • Habitat loss due to coastal development
  • Pollution and marine debris (like plastic)
• Protected by:
  • International treaties and conservation laws
  • Nesting site protection and turtle excluder devices (TEDs) in fishing nets
  • Conservation programs in Mexico and the United States

Interesting Facts

• Named after Richard M. Kemp, the fisherman who first documented the species
• One of only two species in the genus Lepidochelys (the other is the olive ridley turtle)
• Known for synchronized nesting behavior, which is rare among sea turtles
• Conservation efforts have helped increase numbers, but it’s still at high risk of extinction

Leatherback Sea Turtle (Dermochelys coriacea)

The leatherback sea turtle is a powerful swimmer and wide traveler, known for its unique rubbery shell, deep-diving abilities, and massive size. It is found in oceans all over the world.

Appearance and Behavior

• Adult size: up to 1.8 meters (6 feet) long
• Weight: up to 700 kg (1,500 lbs)
• Shell is not hard like other sea turtles—it’s leathery, flexible, and dark-colored with white spots
• Has seven ridges running lengthwise down its back
• Can dive over 1,000 meters (3,000 feet) deep in search of food
• One of the strongest swimmers, capable of traveling thousands of miles

Diet and Feeding

• Eats mostly jellyfish, including large species like the lion’s mane jellyfish
• Has sharp-edged jaws to pierce soft-bodied prey
• Helps keep jellyfish populations in check
• Forages in both tropical and cold waters—can tolerate cold temperatures due to a special fat layer and blood flow system

Life Cycle and Reproduction

• Females nest on tropical beaches, mainly in Central America, the Caribbean, and western Africa
• Nesting season: varies by region but typically March to July
• Lays about 60–100 eggs per nest, 4–7 nests per season
• Eggs incubate for about 60–70 days
• Hatchlings are about 6 cm (2.5 inches) long and head to the sea at night
• Becomes mature at around 15–25 years of age

Habitat and Range

• Found in all major oceans, from the Arctic Circle to the southern tip of Africa
• Prefers open ocean but comes to tropical beaches to nest
• Travels the farthest of any sea turtle—can cross the entire Pacific or Atlantic Ocean

Conservation Status

• Listed as Vulnerable to Critically Endangered, depending on the region
• Major threats include:
  • Plastic pollution (mistaken for jellyfish)
  • Fishing gear entanglement
  • Egg harvesting and coastal development
  • Climate change, which affects nesting beaches and hatchling survival
• Protected by international laws, marine reserves, and conservation groups working to monitor nesting and reduce bycatch

Interesting Facts

• Largest of all sea turtles and one of the heaviest reptiles on Earth
• Can regulate its body temperature, allowing it to survive in cold waters
• Capable of traveling over 10,000 miles a year
• Named for its leather-like shell, unlike the hard-shelled turtles in other families
• Plays a vital role in ocean health by feeding on jellyfish and maintaining balance in marine ecosystems

Green Sea Turtle (Chelonia mydas)

The green sea turtle is known for its smooth, heart-shaped shell, herbivorous diet, and importance to coastal ecosystems. It is named not for its shell color, but for the greenish color of its body fat.

Appearance and Behavior

• Adult size: 90–120 cm (3–4 feet) long
• Weight: 136–180 kg (300–400 lbs)
• Shell (carapace) is smooth and oval-shaped, ranging in color from brown to olive with streaks or spots
• Has a small head, beak-shaped mouth, and large flippers
• Swims long distances between feeding and nesting grounds

Diet and Feeding

• Juveniles eat a mixed diet: invertebrates, small fish, and algae
• Adults are herbivores, eating mostly seagrass and algae
• Has a finely serrated jaw for grazing underwater plants
• Plays a key role in maintaining healthy seagrass beds, which support many marine species

Life Cycle and Reproduction

• Nests on tropical and subtropical beaches worldwide
• Major nesting sites include Costa Rica, Florida, Australia, and the Caribbean
• Nesting season varies by region, but generally May to September
• Females lay 85–120 eggs per nest, 3–5 nests per season
• Eggs hatch after 45–70 days, and hatchlings head to the sea
• Reaches sexual maturity between 20–50 years old
• Can live for 60–70 years or more

Habitat and Range

• Found in tropical and subtropical oceans worldwide
• Common in shallow coastal areas, lagoons, bays, and coral reefs
• Migrates long distances between feeding grounds and nesting beaches

Conservation Status

• Listed as Endangered
• Major threats include:
  • Illegal egg collection and hunting
  • Fishing gear entanglement
  • Habitat loss, especially nesting beaches
  • Pollution and plastic ingestion
  • Climate change, which affects sand temperature (determining hatchling sex)
• Protected under international agreements and national laws
• Conservation efforts include nest protection, tracking programs, and community education

Interesting Facts

• Named for the green fat inside its body, caused by its plant-based diet
• One of the few herbivorous sea turtles, especially in adulthood
• Known for sunbathing—often seen basking on beaches or rocks in Hawaii
• Females return to the exact beach where they were born to lay eggs
• Helps support marine ecosystems by grazing on seagrass and preventing overgrowth

Loggerhead Sea Turtle (Caretta caretta)

The loggerhead sea turtle is one of the most widespread sea turtle species. It is known for its big head, strong beak, and ability to crush hard-shelled prey like crabs and mollusks.

Appearance and Behavior

• Adult size: 85–110 cm (2.8–3.6 feet) long
• Weight: 115–180 kg (250–400 lbs)
• Has a reddish-brown, heart-shaped shell (carapace) and yellowish-brown underside
• Named for its large head, which holds strong jaw muscles
• Swims long distances and spends most of its life at sea, except when nesting

Diet and Feeding

• Eats mostly hard-shelled animals like crabs, clams, mussels, and sea urchins
• Also eats jellyfish, sponges, and fish
• Uses its strong beak-like jaws to crush prey
• Juveniles may eat more floating prey, like small invertebrates and algae

Life Cycle and Reproduction

• Nests on sandy beaches, often along the U.S. East Coast, Mediterranean, Australia, and Japan
• Nesting season: usually May to August
• Females lay 100–120 eggs per nest, 3–6 nests per season
• Eggs hatch in about 50–70 days, and hatchlings crawl to the ocean
• Reaches sexual maturity at 20–35 years old
• May live up to 60 years or more

Habitat and Range

• Found in temperate and subtropical oceans around the world
• Common in the Atlantic, Pacific, and Indian Oceans
• Lives in coastal bays, estuaries, open ocean, and near coral reefs
• Migrates thousands of miles between feeding and nesting areas

Conservation Status

• Listed as Vulnerable globally, but some populations are Endangered
• Major threats include:
  • Fishing gear entanglement (especially longlines and trawls)
  • Coastal development and beach lighting near nesting sites
  • Pollution and plastic ingestion
  • Climate change, affecting nesting beaches and hatchling survival
• Protected by international conservation laws and nest monitoring programs

Interesting Facts

• Named for its extra-large head, which helps it crush hard prey
• Has one of the strongest bites of any sea turtle
• Hatchlings use the moonlight to find the sea—artificial lights can confuse them
• Females often return to the same beach where they hatched to nest
• Plays an important role in coastal ecosystems by controlling prey populations and helping cycle nutrients

Hawksbill Sea Turtle (Eretmochelys imbricata)

The hawksbill sea turtle is a tropical species found mainly in coral reefs. It is easily recognized by its sharp, pointed beak and colorful shell, which has been heavily targeted by the illegal wildlife trade.

Appearance and Behavior

• Adult size: 60–90 cm (2–3 feet) long
• Weight: 45–70 kg (100–155 lbs)
• Shell (carapace) is overlapping and serrated, with beautiful amber, brown, and gold streaks
• Named for its hooked beak, similar to a hawk’s
• Excellent swimmers, often found weaving through coral reef crevices

Diet and Feeding

• Eats mainly sponges, especially toxic ones that most animals avoid
• Also eats anemones, soft corals, jellyfish, and algae
• Uses its narrow beak to reach food in cracks of coral reefs
• Plays an important role in reef health by controlling sponge growth

Life Cycle and Reproduction

• Nests on remote tropical beaches, especially in Caribbean, Seychelles, Indonesia, and Australia
• Nesting season varies by region, often June to December
• Females lay 100–140 eggs per nest, 2–5 nests per season
• Incubation takes 50–70 days
• Hatchlings are about 4–5 cm (1.5–2 inches) and head to the sea at night
• Reaches sexual maturity at 20–35 years
• Can live for 50+ years

Habitat and Range

• Found in tropical and subtropical oceans around the world
• Most common in the Caribbean Sea, Indo-Pacific, and East Africa
• Prefers coral reefs, rocky coastlines, lagoons, and mangroves
• Rarely seen far from shore

Conservation Status

• Listed as Critically Endangered
• Major threats include:
  • Illegal shell trade (for “tortoiseshell” jewelry and décor)
  • Egg harvesting and poaching
  • Habitat loss and coral reef degradation
  • Fishing gear entanglement
  • Climate change affecting nesting success
• Protected under international laws (like CITES) and national wildlife acts
• Conservation groups monitor nests and work to reduce illegal trade

Interesting Facts

• Shell is highly prized, once used for combs, glasses, jewelry, and ornaments
• Named for its hawk-like beak, used to reach food in coral cracks
• One of the few animals that eat toxic sponges without harm
• Hatchlings are often eaten by birds, crabs, and fish before reaching the sea
• By eating sponges, they help coral reefs thrive by preventing overgrowth

Evaluations:

• Student participation
• Student created craft

Extensions:

• Students write a fiction or nonfiction story about a sea turtle
• Students create their own model of a sea turtle using maker space materials
• Students complete various sea turtle worksheets and lessons
• Students can read other books or research about other types of sea turtle

Lesson by: Amy Tapia, Tanya Schilinger, Karleen Pape, Mandy McFall, Gina Betancourt-More