This is a text version of the notes presented in class.

Feel free to email the instructor (dpalmer@kent.edu) with any
comments about the format and ease of use of these online notes.

1. Charismatic Megafauna (Marine Mammals)
- Classification of Marine Mammals
- Whales and Whaling
 

2.Classification of Marine Mammals
Cetaceans: Porpoises, Dolphins, Whales
Carnivora (Pinnipedia): Seals, Seal lions, Walruses
Sirenia: Manatees, Dugongs

3. Traits Common to All Marine Mammals
- Streamlined body shape
- Generate internal body heat
- Modified respriratory system
- Adaptations to salt water environment

4. Adaptations Common to Many Marine Mammals
Large body size
 - reduces heat loss
Blubber/fat layer
 -insulates against cold
 -stores food reserves
 - aids in floatation
 - improves streamlining

5. Seals and Sea Lions - What's the Difference?
Seals:
- smooth heads
- use webbed hind feet spread vertically like the back fin of fishes
Sea Lions:
- protruding ears
- front flippers as paddles
- hind limbs have greater range of motion
Both leave the ocean to mate and raise young

6. The Diving Reflex
Per kg of mass, marine mammals store more oxygen than humans
- most oxygen is stored in body tissues, not the lungs
(see lecture for correct formatting of table below)
Oxygen in         30kg seal       70 kg human
Lungs                  55 ml               720 ml
Blood              1125 ml             1000 ml
Muscle and        370 ml               440 ml
 tissue water
Total                1550 ml             2160 ml
Oxygen per kg   52ml/kg             31ml/kg
 

7. Toothed Whale Species
Large brains for advanced sound processing
Prey depends on size:
Small (porpoises,dolphins)
- small squids and fish
Larger (killer)
- fish, penguins, seals, sea lions, porpoises
Very large (sperm)
- giant squid

8. Toothed Whales
Toothed whales hunt using echolocation (biological equivalent of sonar)
Modifications of head and respiratory systems allow
- sending and receiving sounds over a wide range of frequencies
- focusing the direction of the sound they emit

9. Baleen Whales
Baleen:
-sheets of closely-spaced parallel plates
- used to strain food
Feeding strategies:
- sieve while moving forward
- lunging into schools of prey
- scooping mud from the bottom
Each feeding strategy corresponds to different body types

10. Giant Size from Tiny Food!
Baleen whales are the largest known animals
A diet abundant in plankton provides the energy that these giants need to survive

11. Baleen Whale Species
Sieving (right, bowhead)
- large mouths
- long baleen fringes
Lunging (minke, blue, humpback, fin, sei)
- smaller mouths (that open wide)
- pleats or furrows in throat
Bottom feeders (grey)
-adapted for scooping sediment

12. Whale Migrations and Navigation
Whales can migrate 1000's of kilometers
Many whales move between
-warm water wintering grounds
-cold water feeding grounds
Navigation
- based on sensing Earth's magnetic field
- fluctuations in the magnetic field may explain mass strandings of whales
 

13. Migrations, Whale Songs and Identification
During migrations, whales vocalize ("sing") to stay in contact
This is particularly important for young whales, who must remain near their mothers
A whale's song is as distinctive as its markings

14. Breaching and Spyhopping
Whales exhibit many complex behaviors
Breaching may help establish dominance
Spyhopping in coastal waters may help whales get their bearings

15. A Timeline of the Whaling Industry
1600s  First major commercial whaling
1868   Invention of explosive harpoon gun
1900s  Use of motorized ships and "factory" ships
1930s  Blue whales reduced to 4% of original numbers
1946   Formation of International Whaling Commission (IWC)
 

16. A Timeline of the Whaling Industry
1979  IWC moratorium on whaling (Indian Ocean) outlaws use of factory ships
1985  Start of global commercial whaling moratorium
1994  Establishment of whale sanctuary (Antarctic waters)
1994  Grey whale is 1st marine mammal removed from US endangered species list
Commercially extinct whales: fin, sperm, sei, blue, humpback
 

17. The Marine Mammal Protection Act (1972) Bans:
(1) Taking of marine mammals in US territorial waters
(2) Imports of marine mammal products
(3) Taking of marine mammals on the high seas by persons or vessels subject to US jurisdiction
Significantly reduced the dolphin "bykill" from the tuna industry

18. Preview of Next Lecture
Lake Erie, An Inland Sea in Our Backyard
Focus Question:  What are the major issues in lake water quality for Lake Erie?