1. Lesson 21:
Marine Mammals

3. Common characteristics
Marine mammals share the following characteristics:
Give birth to live young
Nurse their young
Endothermic – “warm blooded”
Have hair

4. Marine Mammals Groups:
Cetaceans (whales, dolphins, porpoises)
Pinnipeds (seals, sea lions, walruses)
Sirenians (manatees, dugongs)
Polar Bears
Sea Otters

5. What’s the difference between a dolphin and a porpoise?

7. The main difference between dolphins and porpoises is their teeth
The main difference between dolphins and porpoises is their teeth! Dolphins have cone-shaped teeth, while porpoises have flattened, spade-shaped teeth.

8. While not a perfect rule, porpoises generally have a triangular dorsal fin while dolphins have a more curved dorsal fin.

9. Cetaceans Sleek, bullet shaped bodies Strong tail for propulsion
Long “mouth” area called a rostrum
Move their tails, or flukes up and down

10. Cetaceans Must breathe voluntarily (unlike humans)
Breathe through special hole on top of their heads called a blowhole
Deep divers remain near surface for several minutes to “catch their breath”
Cloud-like blow is a mixture of CO2 and unused O2, liquid water spray, and mucus

11. Cetaceans Unlike most mammals, cetaceans do not have much hair
Instead, layers of fat under skin called blubber
Keeps animals warm and regulate body temperature

12. Two Major Groups 1) Suborder Odontoceti (Toothed whales) Dolphins
Porpoises
Beluga Whale
Killer Whale
Sperm Whale

13. Toothed Whale Characteristics
Eat fish or squid
Use teeth to rip apart prey
Use sound to echolocate, navigate, communicate

14. Two Major Groups 2) Suborder Mysticeti (Baleen whales) Blue whales
Humpback whales
Gray whales
Fin whales

15. Baleen Whales Baleen allows them to strain their food from the water
Diet includes small prey such as krill, small fish and squid

16. NOAA describes 11 species of baleen whales, and 67 species of toothed whales.

17. Behavior of Cetaceans Vary widely between species
Spinner dolphins swim in large pods
Blue whales typically alone or in pairs
Harbor porpoises prefer shallow waters
Sperm whales prefer deep dives to chase squid
Communicate using clicks, whistles, and groans

18. Why we Should Care About Whale Poo…..
TED talk

19. Pinnipeds
All pinnipeds are protected under the Marine Mammal Protection Act (MMPA); some may be designated as "depleted" under the MMPA. Endangered and threatened pinnipeds are further protected under the Endangered Species Act (ESA).

20. Pinnipeds Unique because they give birth and nurse on land
Wide range of environments
Leopard seal in icy Antarctic
Ribbon Seals in Arctic
Harbor Seal along temperate shorelines
Hawaiian Monk Seals near Coral Reef

21. 3 main groups Otaridae (Eared seals)
Includes seals with fur and sea lions
Have an earflap on outside of their bodies
Use longer flippers to walk on land by twisting back limbs forward
Ex: California Sea Lions, Steller Sea Lions, Northern Fur Seals

22. California Sea Lion pup

23. 2) Phocidae (True Seals)
Move on land by wriggling on their bellies
vertical undulating motion called "galluphing”
Ex: Hawaiian Monk Seals, Harbor Seals, and Ringed Seals
Hawaiian Monk Seal
Harbor Seals

24. Ringed Seal

25. 3) Odobenidae (Walruses)
Distinguished by long tusks
Use tusks to dig up shellfish from seafloor

26. What’s the difference between seals and sea lions?
Sea lions (left) are brown, bark loudly, "walk" on land using their large flippers and have visible ear flaps. Seals have small flippers, wriggle on their bellies on land, and lack visible ear flaps.

27. 3) Odobenidae (Walruses)
Also to break through ice and haul themselves onto ice
Unlike other pinnipeds, have very little hair
Very thick skin
Coarse, sensitive bristles around mouths replaced yearly

28. Pinnipeds
Many relax or “haul out” on land in large groups called colonies
Occurs when mothers give birth
Occurs when animals lose their fur, or molt
Some species like Northern Elephant Seal lose their entire top layer of skin and hair

30. Pinnipeds Haul out areas are not always peaceful
Baby Elephant Seal
Haul out areas are not always peaceful
Engage in violent fights over mates
Northern Elephant Seal males establish dominance through intense fighting
Wins them the right to mate with females
Walruses behave similarly