1. (what you took marine science to learn about)
Marine mammals
(what you took marine science to learn about)

2. Fact or fiction? FACT Fiction: 1 Hour FACT Fiction: 30 mph FACT
1. A blowhole is a modified nostril
2. A sperm whale can remain underwater for up to 3 hours
3. Dolphins can eat and swallow underwater without drowning
4. Killer whales can reach speeds of over 60 mph
5. A blue whale calf gains 200 lbs per day in its first year of life
Fiction: 1 Hour
FACT
Fiction: 30 mph
FACT

3. Classification: Kingdom: Animalia Phylum: Chordata Class: Mammalia
Orders:
Pinnipedia:
Seal, Sea Lion, Walrus
Carnivora:
Otter, Polar Bear
Sirenia: Manatee
Cetacea:
Whale, Dolphin

4. What Defines a Mammal? Endothermic (warm-blooded) Hair/Fur for warmth
Internal development (nutrients via placenta)
Nourishment via mammary glands
Very large brain in relation to body size

5. Order: Pinnipedia Seals, Sea Lions, Walruses
Evolved from early carnivores
Paddle-shaped flippers
Rest and breed on land
Feed mostly on fish and squid
Fusiform body shape
Most live in cold water
Very large to prevent heat loss

6. Harbor Seal: North Atlantic, North Pacific
Elephant Seal: Mexico, Southern California
Monk Seal: Tropical Locations
Crabeater Seal: Antarctica
Teeth!

7. Harp Seal
California Sea Lion: trained barking circus seals
Harp Seal Pup

8. The Importance of Blubber
Thick layer of fat for warmth
Food reserve
Buoyancy in water

9. Sea Lions vs. Seals Seals Sea Lions Short Neck No External Ear
Long Neck
External Ear
Posterior (back) flippers move forward for walking
Anterior (front) flippers have no hair/nails and can rotate to support weight
Short Neck
No External Ear
Posterior flippers cannot move forward
Anterior flippers have hair/nails and cannot rotate backward

10. Sea Lions vs. Seals
Sea Lions and Seals

11. Order: Carnivora Sea Otters and Polar Bears
Closely related to dogs/cats

12. Sea Otter Characteristics
Smallest marine mammals (60-80 lbs)
No blubber, stays warm through air trapped in fur
Must eat 25-30% of body weight per day
Live in colder waters, usually in kelp forests
How Do Sea Otters Stay Warm?

13. Sea Otter Eating Habits
Usually eat urchins, mussels, and crabs
Carry a flat rock in side pockets of loose fur and use it to crush shells of urchins and crabs

14. Polar Bears Found in polar north regions such as Canada
Spend most time drifting on ice sheets
Eat mostly seals

15. Order: Sirenia Manatees, Dugongs (aka sea cows)
Relatives of the elephant
Only front flippers, no rear limbs
Vegetarians, eat sea grass
Slow reproduction (one calf every 3 years)
Only four species left (3 manatee and 1 dugong)
Steller’s Sea Cow (now extinct) largest: 7.5 meters

17. Steller’s Sea Cow
1741: Explorers sailing through the Commander islands (near Alaska) discovered this living relative of the manatee
Within 27 years of discovery, Europeans hunted it to complete extinction for its blubber (used to make oil), and its skin was used to make boats
Easy target: very slow swimmer and not able to submerge
Manatees and Dugongs

18. Manatees vs. Dugongs Manatees Dugongs Forked Tail Shorter and lighter
Rounded tail
Longer and heavier
Rough Skin
Forked Tail
Shorter and lighter
Smooth skin
Nostrils flare outward

20. Sirenia Distribution

21. Order: Cetacea Whales, dolphins, porpoises
Largest group of marine mammals
Spend entire lives in water
Very fish-like bodies (fusiform)
Front flippers, no rear limbs
90 species- all marine except 5 freshwater dolphins
Blowhole is a modified nostril
Two sub-orders: mysticeti and odonticeti

22. Suborder: Mysticeti Baleen whales
No teeth, feed through filter-feeding
Blue Whale: largest species on Earth (27 meters)
Why are Whales So Big?

24. How Does the Baleen Work?
Baleen = flexible, fibrous plates made of keratin and hangs from upper jaws
Whale intakes a mouthful of water, raises tongue and squeezes water out through bristles
Food is then licked off the baleen

25. Gray Whale: North Pacific coastlines Right Whale: North Atlantic
Types
Right Whale: North Atlantic
Bowhead Whale: Arctic

26. Rorqual Whales Accordion-like lower throat expands when feeding
Examples: Humpback, Blue, Fin Whales

27. Order: Odonticeti
Toothed whales: Beluga, Narwhal, Killer Whale (Free Willy), Sperm Whale (Moby Dick), Dolphins, Porpoises
Teeth used to catch and hold prey, not to chew it
Feed mostly on fish and squid

28. Bottlenose Dolphin (Flipper)
Porpoise
Sperm Whale
Amazon River Dolphin
Bottlenose Dolphin (Flipper)

30. Diving Adaptations Contain blood with increased concentration of RBC
Muscle cells have more myoglobin than normal (myoglobin stores oxygen)
Heart rate dramatically decreases underwater (elephant seal drops from 85 beats per minute to 12)
Blood flow to non-essential body parts is decreased
Lungs collapse to squeeze excess air out to prevent air from dissolving in the blood
How a Seal Survives Underwater

31. Echolocation Sensory system based on hearing Nature’s version of sonar
Used by all toothed whales and some baleen whales
Low frequency sound waves are emitted by the cetacean
Living Waters- Dolphin Echolocation

32. Nasal passages help to emit sound waves (clicks)
The melon focuses these clicks into one outgoing beam
Fat-filled lower jaw receives sound waves as they are bounced back toward the cetacean, and a sound picture is created by the brain

33. Cetacean Behaviors Large brain promotes learning and memory
Humpback Whale Song
Large brain promotes learning and memory
Highly social animals, most live in large groups (pods)
Communicate via many different types of sounds and vocalizations
Humpback whale renowned for soulful songs used during mating
Often assist injured members of their pod, many refuse to leave an injured or dying comrade
Whalers knew a harpooned whale was a lure for others

34. Humpback Whale Breaching
Dolphin Superpod
Humpback Whale Breaching
Scoliosis Caused by Beaching
Why Do Whales Beach Themselves?
Pod of beached whales in Australia

35. Reproduction (Pinnipeds)
Internal fertilization on land
Most seal species, males mate with only one female
Elephant seals, fur seals, and sea lions:
One male herds large harems of females (up to 50)
All other males from “bachelor groups”
Delayed implantation: Allows the birth of pups to be timed with the arrival of pregnant females in breeding areas (embryo remains dormant after fertilization

36. Reproduction (Cetaceans)
Dolphin Giving Birth
Internal fertilization, male reproductive organs also internal and extruded out of a genital slit when used
Appear to have sex for pleasure as well as procreation
Calves born tail first to prevent drowning
Gray whales mate with the help of a second male to prop up female

37. Current Problems
Whales and dolphins have been famously overfished for centuries
Presently, dolphins are more threatened
Less than 600 vaquitas left in the world
Less than 100 Yangtze River dolphins
Many get caught in tuna nets
Suffering due to overfishing of tuna and squid (their food)

38. Conservation Efforts
International Whaling Commision (IWC): est. in 1946, 20 whaling nations regulating hunting and overfishing of cetaceans
Very hard to enforce
Japan, Norway, Iceland still major offenders
Marine Mammal Protection Act of 1972 (USA):
Banned hunting of all marine mammals in US waters