1. Marine Mammals
photos: Florida FWC, NOAA

2. Reptiles, Birds, Mammals
Phylum Chordata
Subphylum Vertebrata
3 Classes:
Class Reptilia
Class Aves (birds)
Class Mammalia

3. Mammals Advantages over reptiles:
Endotherms, homeotherms (retain generated body heat and regulate it to a constant temp.)
Skin covered with hair
Layer of body fat
Viviparous, placenta, mammary glands
Large brain (relative to body size)

4. Marine Mammals Mammals evolved ~200 mya
Some from land reinvaded the oceans ~50 mya
Breathe air
Adaptations for diving
Several orders:
Carnivora

5. Sea Otters Order Carnivora Family Mustelidae
Second smallest marine mammal (up to 5 ft, 100 lbs)

6. Sea Otters No blubber, traps air in thick fur for insulation
Hunted near extinction for fur til 1911
Still treatened

7. Sea Otters Other threats: Oil spills
Predators – killer whales, sharks, eagles

8. Sea Otters Webbed hind feet Dive up to 300 ft, 5 min
Average dive: 65 ft, 1.5 min
USGS

9. Sea Otters Dexterous front feet
Use rocks as tools to open urchins, clams, mussels, abalone, crabs
Key part of kelp communities
photos: USFWS

10. Sea Otters When otter populations decline, urchins increase
Urchins overgraze, cut through holdfasts, stipes
Kelp sent adrift, strand on beach
Bottom left barren

11. Sea Otters Reproduction: Breed every 1-2 yrs 1 pup born (3-5 lbs)
Nurse for many months

12. Marine Otters Same subfamily as sea otters Smallest marine mammal
(up to 3 ft, 10 lbs)
Pacific coast of S. America

13. Polar Bears Order Carnivora, Family Ursidae
Spend time on floating sea ice
Thick blubber and fur to retain heat
Eat mostly seals
Top carnivore in Arctic food chain AP

14. Polar Bears AP

15. Polar Bears Pregnant females dormant in maternity den until spring
Usually 1-2 cubs, nurse for 2.5 yrs
Breed every 2-3 yrs
photos: USFWS

16. Polar Bears Currently a threatened species on endangered species list
Estimated 20-25,000 worldwide
Global warming → shrinking ice
ACIA Report, 2004, p25

17. Polar Bears Excellent swimmers
At risk of starvation and drowning from travel between distant ice packs

18. Pinnipeds Order Carnivora (formerly Pinnipedia)
True seals (Phocidae) – 18 species
Eared seals (Otariidae)
Sea lions – 6 species
Fur seals – 9 species
Walruses (Odobenidae) – 1 species
Most closely related to bears

19. Pinnipeds Streamlined bodies, paddle-shaped flippers for swimming
Predators - eat mostly fish, squid
Elephant seals – dive to 1500m, stay underwater up to 2 hours
Mostly cold water, thick layer of blubber
Rest and breed on land

20. Seals vs. Sea Lions

21. Seals of Long Island Males 5.5 ft, 250 lbs Females a little smaller
NOAA
Harbor seal (Phoca vitulina)
Grey seal (Halichoerus grypus)
Males 5.5 ft, 250 lbs
Females a little smaller
North Atlantic &
Pacific
Males 8 ft, 800 lbs
Females 7 ft, 400 lbs
North Atlantic (both sides)

22. Seal walk - Cupsogue Beach
Seals of Long Island
Seal walk - Cupsogue Beach

23. Seal walk - Cupsogue Beach
Seals of Long Island
Seal walk - Cupsogue Beach

24. Riverhead Foundation seal release
Seals of Long Island
Riverhead Foundation seal release
Ponquogue Beach

25. Seals of Long Island http://www.cresli.org/cresli/images/sealmap2.jpg

26. Arctic Seals Harp seals (Pagophilus groenlandicus)
Hooded seal (Cystophora cristata)
NOAA
Spotted seal
Ringed seal (Phoca hispida)

27. Antarctic Seals Weddell seals Leopard seal Crabeater seal NOAA NOAA

28. Other Seals Hawaiian monk seal Ribbon seal
NOAA
Hawaiian monk seal
Ribbon seal
Elephant seal – largest Pinneped

29. Sea Lions and Fur Seals
Differ from true seals anatomically and geographically
True seals – more widespread, many oceans
Eared seals – mostly Pacific
Fur seals smaller
than sea lions
NOAA
Fur seals

30. Sea Lions
Steller and California sea lions
photos: NOAA, USFWS

31. Sea Lions California sea lions Pier 39, San Francisco
New York Aquarium
California sea lions

32. Walruses One species, only in Arctic
Distinctive tusks, for defense and to grab hold of ice
Eats bottom invertebrates (clams)
Stiff whiskers as feelers
photos: NOAA, USFWS

33. Manatees and Dugongs Order Sirenia (“sea cows”) Manatees (3 species)
Dugongs (1 species)
Steller’s Sea Cow
Entirely aquatic life
Most closely
related to elephants

34. Sirenians No rear limbs (except as embryos)
Flattened tail, moves up/down
Large, round body, blubber
Strictly vegetarian (seagrass, aquatic plants)

35. Sirenians Slow reproduction (1 calf every few years) Mammary glands
under armpits
Florida FWC
Florida FWC

36. Sirenians All species endangered or extinct
Hunted for meat, skin, blubber
Hit by boaters (swim slow, near surface)
Florida FWC
Robert

37. Sirenians Entangled in nets, lines
Losing habitat (destruction of seagrass beds)
Approx manatees around Florida
2013 record mortality = 829 (16% of population) due to
red tide, unk. disease
Normal mortality
/year

38. Steller’s Sea Cow Largest sirenian (25 ft)
Discovered 1741, Bering Sea, Alaska
Extinct since 1768

39. Dugongs vs. Manatees

40. Dugongs
Red Sea, Indian Ocean to Western Pacific, especially around Australia
Strictly marine

41. Manatees Atlantic Ocean, Gulf of Mexico, Amazon River, West Africa
Coastal bays, rivers, warm springs, and power plant discharge canals (salt or freshwater)
Florida FWC
Florida FWC

42. Manatee Surveys Florida FWC

43. Wayward Manatees Sometimes migrate out of normal areas
“Chessie” – tagged by USGS, seen in NY, Rhode Island 1995; Virginia 1996, 2001
Hudson River, August 2006
LIS, August 2010
Mississippi River
near Memphis, Tenn.
(700 miles from Gulf),
Fall 2006