ch15-Literature Cited

/by

Literature Cited

Anonymous. 1971. Arrow oil spill. Smithsonian Institution. Center for Short Lived Phenomena. Annual Report 197, Event No. 36-70:134-136.

Babin, P., and R. Duguy. 1985. Intoxication due aux hydrocarbures ingeres par Halichoerus grypus et Phoca vitulina. CM1985/N: 12. London: Conseil International Exploration de la Mer.

Baker, J. R., A. M. Jones, T. P. Jones, and H. C. Watson. 1981. Otter Lutra lutra L. mortality and marine oil pollution. Biological Conservation 20:311-21.

Bowyer, R. T., J. W. Testa, J. B. Faro, and L. K. Duffy. 1993. “Effects of the Exxon Valdez oil spill on river otters in Prince William Sound.” In Proceedings of the Exxon Valdez oil symposium, Anchorage, AK. 297-299. Anchorage: The Oil Spill Public Information Center.

Costa, D. P., and G. 1. Kooyman. 1982. Oxygen consumption, thermoregulation, and the effect of fur oiling and washing on the sea otter, Enhydra lutris. Canadian Journal of Zoology 60 (11): 2761-67.

Davis, J. E., and S. S. Anderson. 1976. Effects of oil pollution on breeding grey seals. Marine Pollution Bulletin 7:115-18.

Duffy, 1. K., R. T. Bowyer, J. W. Testa, and J. B. Faro. 1993. Differences in blood haptoglobin and length-mass relationships in river otters (Lutra canadensis) from oiled and non-oiled areas of Prince William Sound, Alaska. Journal of Wildlife Diseases 29:353-59.

Engelhardt, F. R. 1982. Hydrocarbon metabolism and cortisol balance in oilexposed ringed seals, Phoca hispida. Comparative Biochemistry and Physiology 72C:133-36.

Engelhardt, F. R. 1985. “Effects of petroleum on marine mammals.” In Petroleum effects in the arctic environment. F. R. Engelhardt, ed., 217-43. London: Elsevier Applied Science.

Engelhardt, F. R., J. R. Geraci, and T. G. Smith. 1977. Uptake and clearance of petroleum hydrocarbons in the ringed seal, Phoca hispida. Journal of the Fisheries Research Board of Canada 34:1143-47.

Frost, K. J., C. Manen, and T. 1. Wade. 1994. “Petroleum hydrocarbons in tissues of Harbor Seals from Prince William Sound and the Gulf of Alaska.” In Marine mammals and the Exxon Valdez. T. R. Loughlin, ed., 331-358. San Diego: Academic Press, Inc.

Gales, N.J. 1991. New Zealand fur seals and oil: An overview of assessment, treatment, toxic effects, and survivorship. Mount Pleasant, Western Australia: Report of the West Australian Department of Conservation and Land Management.

Geraci, J. R., and V. J. Lounsbury. 1993. Marine mammals ashore: A field guide for strandings. Galveston: Texas A&M Sea Grant Publication.

Geraci, J. R., and T. G. Smith. 1976. Direct and indirect effects of oil on ringed seals (Phoca hispida) of the Beaufort Sea. Journal of the Fisheries Research Board of Canada 33 (9): 1976-84.

Geraci, J. R., and T. D. Williams. 1990. “Physiologic and toxic effects on sea otters.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds., 211-21. San Diego: Academic Press, Inc.

Johnson, 1. 1983. Assessment of the effects of oil on arctic marine fish and marine mammals. Canadian Technical Report of Fisheries and Aquatic Sciences 1200:1-15.

Kooyman, G. 1., R. 1. Gentry, and W. B. McAllister. 1976. Physiological impact of oil on pinnipeds. Report. Northwest Fisheries Center, National Marine Fisheries Service, Seattle.

Kooyman, G. 1., R. W. Davis, and M. A. Castellini. 1977. “Thermal conductance of immersed pinniped and sea otter pelts before and after oiling with Prudhoe Bay crude.” In Fate and effects of petroleum hydrocarbons in marine ecosystems and organisms. D. A. Wolfe, ed., 151-57. New York: Pergamon Press.

Le Boeuf, B. J. 1971. Oil contamination and elephant seal mortality: A “negative” finding. Biology and oceanography of the Santa Barbara Channel oil spill: Volume 1, Biology and Bacteriology. 1:277-85.

Lillie, H. 1954. Comments in discussion. 31-33. London: Proceedings of the International Conference on Oil Pollution.

Loughlin, T. R. 1994. Marine mammals and the Exxon Valdez. San Diego: Academic Press, Inc.

McLaren, I. A. 1990. “Pinnipeds and oil: Ecological perspectives.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds., 55-101. San Diego: Academic Press, Inc.

Neff, J. M. 1990. ” Composition and fate of petroleum and spill-treating agents in the marine environment.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds.,1-33. San Diego: Academic Press, Inc.

0ritsland, N. A 1975. “Insulation in marine mammals: The effect of crude oil on ringed seal pelts.” In The effect of contact and ingestion of crude oil on ringed seals of the Beaufort sea. T. G. Smith and J. R. Geraci, eds., 48-67. Beaufort Sea Project Technical Report No.5, Institute of Ocean Science,Sidney, British Columbia.

0ritsland, N. A, F. R. Engelhardt, F. A Juck, R. A Hurst, and P. D. Watts. 1981. Effects of Crude Oil on Polar Bears. Environmental Studies Report No. 24. Northern Affairs Program, Department of Indian Affairs and Northern Development, Ottawa, Ontario, Canada.

Richardson, M. G. 1979. The environmental effects of the Esso Bernicia fuel oil spill, Sullom Voe, Shetland. Jan 1979. Interim Report to the nature Conser vancy Council. Lerwick, N. C. C

St. Aubin, D. J. 1990a. “Physiologic and toxic effects on pinnipeds.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds., 103-27. San Diego: Academic Press, Inc.

St. Aubin, D. J. 1990b. “Physiologic and toxic effects on polar bears.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds., 235-339. San Diego: Academic Press, Inc.

St. Aubin, D. J., and J. R. Geraci. 1986. Adrenocortical function in pinniped hyponatremia. Marine Mammal Science 2 (4): 243-50.

Shaughnessy, P. D., and P. Chapman. 1984. Commensal Cape fur seals in Cape Town docks. South African Journal of Marine Science 2:81-91.

Smith, T. G., and J. R. Geraci. 1975. The effect of contact and ingestion of crude oil on ringed seals of the Beaufort Sea. Beaufort Sea Project, Technical Report No.5 Institute of Ocean Science, Sidney, British Columbia, Canada.

Spraker, T. R., 1. E. Lowry, and K. J. Frost. 1994. “Gross necropsy and histopathological lesions found in harbor seals.” In Marine mammals and the Exxon Valdez. T. R. Loughlin, ed., 281-312. San Diego: Academic Press, Inc.

Stirling, I. 1990. “Polar bears and oil: Ecological perspectives.” In Sea mammals and oil: Confronting the risks. J. R. Geraci and D. J. St. Aubin, eds., 223-34. San Diego: Academic Press, Inc.

Stirling, I., C. Spencer and D. Andriashek. 1989. Immobilization of polar bears
(Ursus maritimus) with Telazol. Journal of Wildlife Diseases 25 (2): 159-68.

Warner, R. E. 1969. Environmental effects of oil pollution in Canada: An evaluation of problems and research needs. Report of the Canadian Wildlife Service, Ottawa, Canada.

Williams, T. D., and G. R. VanBlaricom. 1989. Rates of capture myopathy in translocat_d sea otters, with implications for management of sea otter rescue following oil spills. Proceedings of the Eighth Biennial Conference on the Biology of Marine Mammals, Pacific Grove, California.

Williams, T. D., A. L. Williams, and M. K. Stoskopf. 1990. “Marine mammal anesthesia.” In CRC handbook of marine mammal medicine: Health, disease, and rehabilitation. 1. A Dierauf, ed., 175-94. Boca Raton: CRC Press.

Williams, T. M., G. A Antonelis, and J. Balke. 1994. “Health evaluation, rehabilitation, and release of oiled harbor seal pups.” In Marine mammals and the Exxon Valdez, T. R. Loughlin ed., 227-242. San Diego: Academic Press, Inc.

Williams, T. M., and R. W. Davis. 1990. Sea otter rehabilitation program: 1989 Exxon Valdez oil spill. Report to Exxon Company, USA. International Wildlife Research. .

Williams, T. M., R. Wilson, P. Tuomi, and L. Hunter. 1990. “Critical care and toxicological evaluation of sea otters exposed to crude oiL” In Sea otter rehabilitation program: Exxon Valdez oil spill. T. M. Williams and R. W. Davis, eds., 82-100. Report to Exxon Company USA. International Wildlife Research.

natural-history-classification

/by

Classification

Sea Otters are Mammals

What are Mammals?
They are a group of animals comprising three phylogenetic orders that have adapted to spending all or significant portion of their life in the marine environment.

NatHist_MarineMammals

Marine mammals retain the basic characteristics common to all mammals

  • endothermic homeothermy
  • hair
  • live birth
  • nourish young with milk

Marine Mammal Groups

1) Whales and Dolphins: Order Cetacea

NatHist Cetacea

2) Manatees and dugongs: Order Sirenia

NatHist Manatees

3) Seals, sea lions and walrus: Order Carnivora

NatHist Carnivora.

4) Sea Otters and polar bears: Order Carnivora

NatHist Carnivora2

Marine mammals of the Order Carnivora
Suborder-Pinnipedia
Families-
Otariidae (16)
Odobenidae (1)

Phocidae (19)

Suborder-Fissipedia
Families-
Mustelidae (2)
Sea otter (Enhydra lutris)
Marine otter (Lontra felina)
Ursidae (1)

Order-Carnivora

1. Skin – possess hair and/or vibrissae; well developed layer of subcutaneous blubber except for sea otters, which have little subcutaneous fat
.

2. Limbs – modifications range from fore and hind flippers (pinnipeds- seals, sea lions and walrus) to interdigital webbing (sea otter hind limbs) to essentially none (polar bears)
.

3. Tail – ranges from well developed (sea otter) to small (seals and sea lions) to absent (walrus)
.

4. Pinnae-pinnae (external ear) present except in seals and walrus
5. Nostrils- can be closed in pinnipeds
.

Only sea otters and fur seals use fur as a thermal insulator.  The fur is dense but not long and traps an air layer next to skin.

Suborder- Fissipedia

Family- Mustelidae (includes sea otter and marine otter)
-pinnae present
-body has dense fur; essentially no blubber layer
-front paws (not flippers) haired; claws terminal and retractable; used for manipulating objects and movement on land
-hind limbs webbed like a flipper; can be directed in an anterior or posterior direction; used for propulsion in water and for movement on land; claws terminal but not retractable
-tail long
-male larger than female

Sea otters are thought to have evolved from the otters of the Pliocene of India and eastern Asia and moved northward along the western shore of the North Pacific.

natural-history-evolution

/by

Evolution

NatHist Evolution Chart

natural-history-distribution

/by

Distribution

natural-history-anatomy

/by

Anatomy

Gross Anatomy

NatHist GrossAnatomy

Pup Gross Anatomy

NatHist Gross Anatomy Pup

Sea otter Skull

NatHist Sea Otter Skulls

Head Morphology

NatHist Head Morphology

Fore and Hind Paws

NatHist paws

Male Sexual Organs

NatHist sex.

natural-history-fur

/by

Fur as an Insulator

Fox

Fur is a major barrier to heat flow because it traps still air next to the skin. Because of the low specific heat capacity of air (0.24 cal/g/°C), it acts as a barrier to convective heat flow. As one might expect, the insulation value of fur increases with the thickness of the fur (and the air layer) and reaches the maximum for some of the larger terrestrial mammals such as the arctic fox.

However, among marine mammals, long fur does not occur, probably because of the increased hydrodynamic drag that it creates. As a result, marine mammals that rely on fur such as sea otters have a very dense, but short fur.

NatHist fur Insulator

Although the average fur insulation of sea otters in water is good (ca. 0.3 m2 °C/W), it is not as good as that of the arctic fox in air (1.2 m2 °C/W). However, if an arctic fox were immersed in water, the insulation of its fur would not be as good as that of a sea otter. Hence the fur of sea otters is a compromise between good insulation and hydrodynamic properties.

Sea otter fur is the densest of any mammal and is composed of stout overhairs (guard hairs) and shorter, finer underhairs. Hair density ranges from 26,413 to 164,662 per cm2, with highest densities on the forearms (164,662), sides (157,264), rump (118,691), stomach (82,251), and back (77,526). The lowest densities are found on the chest (34,639), legs (30,761), and feet (26,413). Each hair bundle contains one guard hair and a variable number of underhairs (range = 12 underhairs per bundle on the legs to 108 underhairs per bundle in the mid-lateral areas).

NatHist Hair Follicle

Hair follicle morphology of (A) a terrestrial mammal and (B) a sea otter. (C) Cross-sectional views of the arrangement of hairs in follicles for a dog, seal and sea otter.

NatHist Hair Follicle

The length of the guard hairs (2.6-31.5 mm) and underhairs (1.5-26.3 mm) also varies with location on the body, with the shortest hairs on the legs and feet. The guard hairs are oval to round in cross section and have a diameter that ranges from 44-106 microns (mean diameter = 70 microns). Underhairs, which are irregularly shaped due to cuticular scales, are wavy and have a mean diameter of 10.3 microns. Sea otters appear to replace their hair throughout the year and do not have a seasonal molt.

 

 

 

 

Cross sectional view of sea otter fur and microscopic view of shaved hair follicles

NatHist Hair Follicle

In the cold marine environment, the fur of sea otters is not sufficient to maintain a core body temperature Therefore, sea otters must augment heat production Their resting metabolic rate tends to be 2-3 times higher than that for a terrestrial mammal of equivalent size. The skin of the seal has relatively thin fur and a heavy layer of blubber, which provides most the insulation.

Sea otters may eat 25% of their body mass in food each day to support the high metabolic rate.

natural-history-locomotion-water

/by

Locomotion in Water

  • Sweeping motion of the tail while at the surface feeding or grooming; low velocity.
  • Paddling at the surface using alternating thrusts and recovery of the hindlimbs while floating on the belly or back; long distance travel at 0.5-1.0 m/sec.
  • Submerged swimming using craniocaudal thrusts of the hindlimbs, including bending of the lower spine; average velocity of 1.0 m/sec.

The hydrodynamic drag experienced by marine mammals is reduced by a streamlined body shape and internalized limbs. The better the streamlining, the lower the drag force.

Natural history hydrodynamic

Optimum streamlined shapes with minimum drag have a fineness ratio equal to 4.5. Streamlined fish usually have a fineness ratio from 5 to 7. Semi-aquatic mammals, such as the mink have a fineness ratio of 9.3: sea otters 5.4. More aquatic pinnipeds and cetaceans have fineness ratios of between 4.4 and 4.8, which approximate the ideal shape to minimize drag.

Natural history hydrodynamic

The increased drag experienced by an animal swimming at the surface, results from the additional force generated by the surface wave or wake. Drag force approaches a maximum at the surface and decreases to a minimum at ca. three body diameters below the surface. Consequently, it is easier for an animal to swim below the surface than at the surface.

Natural history hydrodynamic

Hydrodynamic shape, efficient propulsion and subsurface swimming allow marine mammals to swim at very low energetic cost and achieve high speeds.

Natural History Hydrodynamic

natural-history-locomotion-land

/by

Locomotion on Land

Natural history locomotion land

natural-history-abdominal

/by

Abdominal and Thoracic organs

Marine mammals have the same abdominal organs as other mammals.

Natural History Abdominal

Natural History Comparative Anatomy

Natural History Lungs

natural-history-dive

/by

Average and Maximum Dive Duration

Average and maximum dive depths 
for marine mammals

Average and maximum dive depths 
for marine mammals

Average and maximum dive durations 
for marine mammals

Average and maximum dive durations 
for marine mammals