1. Marine Turtles, Mammals and Seabirds
Chapter 9
Marine Turtles, Mammals and Seabirds

2. Marine Reptiles Four types of marine reptiles exist today: Sea Turtles
Sea Snakes
Marine Iguana
Saltwater Crocodile

3. Sea Turtles All species of sea turtles are threatened or endangered
Endangered = a species is under direct threat of species survival (extinction is a definite threat)
Threatened = the species may become endangered
Both designations give these species protection under the Endangered Species Act

4. Sea Turtles Seven or eight species of sea turtles exist today:
Leatherback sea turtle
Loggerhead sea turtle
Hawksbill sea turtle

5. Sea Turtles Seven or eight species of sea turtles exist today:
Olive ridley sea turtle
Kemps ridley sea turtle
Australian flatback sea turtle
Green sea turtle

6. Sea Turtles
Structurally, sea turtles have an upper shell known as the carapace and a lower shell known as the plastron. The ribs are expanded in size and fused to their shell
All sea turtles have powerful jaws, but no teeth

7. Sea Turtles
Like other reptiles, sea turtles are poikilothermic and ectothermic although the leatherback sea turtle is so large that its body temperature is normally several degrees above the ambient water temperature

8. Sea Turtles Females normally breed every 2-4 years
These females must return to land to deposit their eggs near the dune line (above the high tide)
Females dig a hole in the sand using only the back flippers
During their breeding year, females may lay up to 7 clutches of eggs
Each clutch of eggs normally has an average of 120 eggs, although large variations in these numbers have been recorded
Leatherback Hatching

9. Sea Snakes There are 55 species of sea snakes
These snakes are found only in the Indian and Pacific Ocean
These snakes have a laterally flattened body with a paddle-like tail for propulsion through the water
Most species are 3-4 feet in length as adults
Banded Sea Krait
Laticauda colubrina

10. Sea Snakes Sea snakes breed at sea and most species are ovoviviparous
A few species still return to land to lay eggs
Bites from sea snakes can be fatal for humans– the sea snakes are related to the cobra and have powerful venom
Fortunately, sea snakes are not known to be aggressive
Sea snakes are carnivorous and mainly feed on fish
Olive sea snake
(Aipysurus laevis)

11. Marine Iguanas Marine iguanas live on the Galapagos Islands
While they are called marine, they only spend a portion of their time in the water
They dive to feed on seagrass near the shore
A large portion of their day is spent basking on the shore to warm up from their dives in the cold water surrounding the Galapagos
marine iguana
Amblyrhynchus cristatus

12. Seabirds Seabirds are endotherms:
able to maintain a constant body temperature derived through metabolic means
The feathers that cover the body are coated with an oil from glandular secretions
This oil helps to waterproof the body
The hard shelled egg provides more protection than the leathery shell of reptiles

13. Seabirds
Many species of seabirds are colonial nesters - they nest in large colonies of individuals near the shore
some on cliffs, others in low shrubs or trees, others directly on the ground
Some species are monogamous and mate for life
Atlantic Yellow-nosed Albatross
Thalassarche chlororhynchos
Atlantic Yellow-nosed Albatross

14. Marine Mammals Characteristics of Mammals: Skin possesses hair
Homeotherms (endotherms)
Mostly viviparous with placenta
Mammary and other glands
Larger brain in relation to body size
Many sexually dimorphic (males and females look different in size, coloration, features, etc)

15. Major Groups of Marine Mammals
Pinnipedia – seals, sea lions and walrus
Carnivora – sea otter and polar bear
Sirenia – dugong and manatees
Cetacea – whales, dolphins and porpoises

16. Order Pinnipedia
Below is a comparison of sea lions/fur seals versus true seals.
Notice the external ear of sea lions/fur seals (not present in seals).
Also notice that sea lions/fur seals can rotate the rear limbs forward for more efficient locomotion on land.

17. Order Pinnipedia Seals: 19 species Most live in cool or cold water
Monk seals are the exception – they live in warmer waters
Hawaiian and Mediterranean monk seals are endangered
Caribbean monk seals have not been seen since the 1950’s
Hawaiian Monk Seal
Monachus schauinslandi
Mediterranian Monk Seal
Monachus monachus
Caribbean Monk Seal
Monachus tropicalis

18. Below is a illustration of a walrus.

19. Order Carnivora Characteristics of Sea Otters fine, dense fur coats
Their forefeet are small and dexterous with retractile claws
flipper-like hind feet are broad and webbed
Consume sea urchins, crabs, abalone, clams, mussels, octopus, and fishes.

20. Order Carnivora Characteristics of Polar Bears:
Polar bears are the largest land carnivore
Thick fur coat that appears white in coloration, but is really translucent.
Black skin color is readily apparent on the nose, eyes, lips and footpads.
Diet includes seals, walruses, narwhals, beluga whales, whale carcasses, fish, reindeer, birds, eggs, berries and kelp
Polar bears hunt for seals

21. Order Sirenia Characteristics of Manatees:
Manatees are primarily herbivores
All living manatee species are found in warm tropical and subtropical waters.
Both fresh and marine manatees
Amazonian Manatee
Trichechus inunguisd
Manatees

22. Order Cetacea Characteristics of Cetacea:
This order includes whales, dolphins and porpoises
Fore limbs are modified into flippers
Fin-like tail is known as a fluke.
Nostrils are located on the top of the head as a single or double opening known as a blowhole.

23. Order Cetacea Two suborders: Baleen Whales (Mysticetes): Two blowholes
Filter feeders: small fish and invertebrates

24. Examples of Baleen Whales

25. Whales may be identified from their fluke shape, blow pattern or side view during a dive (as shown below).

26. Order Cetacea Two suborders: 2. Toothed whales (Odontocetes):
Single blowhole
Single pegged-like teeth
The teeth of dolphins are conical and interlocking, while those of porpoises are spade-shaped
Toothed whales include dolphins, porpoises, belugas, narwhals, sperm whales, killer whales, river dolphins, and beaked whales.

27. Examples of Toothed Whales

28. Adaptations for Diving:
Rapid breathing prior to dive -known as apneustic breathing
Lungs remove 90% of O2 from air (as opposed to 20% for humans)
Marine mammals have more blood than non-diving mammals (means more hemoglobin to carry oxygen)
Muscles employ anaerobic respiration as necessary (results in lactic acid build-up)

29. Echolocation
Sound waves are emitted as a series of clicks of varying frequencies
Melon directs the outgoing sound waves
After the echo strikes an object, it is reflected back
These reflected echoes are received back by the melon and lower jaw
The longer it takes a echo to return, the farther away the object is located

30. Marine Mammal Behaviors
Marine mammals as well known for their vocalizations such as the “barking” of sea lions and songs of the humpback whale.
Marine mammals engage in play activities regularly including sexual play.

31. Marine Mammal Behaviors
Many species of marine mammals are known to jump out of the water and crash back into the water on their backs. This is known as breaching.
The reasons for this behavior may be removing parasites, a warning signal, to avoid suitors or to have fun!

32. Marine Mammal Behaviors
Marine mammals sometimes hold their bodies out of the water. This behavior is known as “spyhopping.”

33. Migration Many marine mammals are known for their long migrations.
The longest migration is that of the gray whale; this migration is over 11,000 miles!!

34. Marine Mammal Behaviors
Care giving and Strandings:
When one member of a group (pod) of animals is sick/injured, other members will care for it. Mass strandings are often the result of caregivers following a sick/injured animal to shore.
As an example, 58 pilot whales mass stranded in July, 2002 at Chapin Beach. Volunteers desperately tried to protect the animals from the summer heat with sheets and water, but unfortunately the elements proved too extreme for the whales.
Cetacea