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Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs (1994)

Chapter: APPENDIX B AN INTRODUCTION TO MARINE MAMMALS

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Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

Appendix B
An Introduction to Marine Mammals

Three orders of the class Mammalia contain marine mammals: Cetacea, Carnivora, and Sirenia. (There is a section on each of the three orders in this appendix. Each includes a table listing the marine mammals in that order.) The size range of marine mammals is immense, varying from a newborn sea otter weighing perhaps 1 kilogram (kg) to the largest female blue whale weighing about 100,000 kg. Their habitats are also quite varied, encompassing all seas and numerous coastal areas and shores as well as some freshwater lakes and rivers.

All extant Cetacea and Sirenia normally spend their entire lives in water. In contrast, marine mammals of the order Carnivora are semiaquatic, often hauling out on land. Some of these semiaquatic mammals spend considerable periods of time (many months) in the water, often hundreds or even thousands of kilometers at sea away from haul-out or breeding areas. Families of marine mammals of the order Carnivora are these: Otariidae, or eared seals (fur seals and sea lions); Odobenidae (walrus); Phocidae (true seals); Mustelidae (chungungo and sea otter); and Ursidae (polar bear).

In the United States, all marine mammals are legally protected by the Marine Mammal Protection Act of 1972 (MMPA). The species of the order Cetacea and suborder Pinnipedia that live strictly in freshwater are also protected under this law, and thus they are included in this discussion. Under the 1972 act, the U.S. Fish and Wildlife Service (FWS) of the U.S. Department of the Interior is responsible

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

for administering regulations concerning polar bears, walrus, sirenians, and sea otters; the National Marine Fisheries Service of the U.S. Department of Commerce is responsible for whales, dolphins, seals, sea lions, and other marine mammals not regulated by FWS. In addition, another independent body established under the MMPA, the Marine Mammal Commission, maintains a scientific committee to advise on issues related to marine mammal conservation. Those species designated as endangered are further protected under the Endangered Species Act of 1973.

Threats to marine mammal populations worldwide are many. They result, for example, from fishing (the use of gillnets, driftnets, ghost nets, long lines, the yellowfin tuna purse seine, rolling hooks), pollution (agricultural runoff, industrial waste, petroleum spills, trash dumping), deforestation and development of the rain forests, damming, oil field development, mining, heavy-vessel traffic, and other human activities.

Twenty species of marine mammals are listed as endangered under U.S. provisions (see the tables in this appendix), although some of them appear to be gaining in population and may be removed from endangered status (Brownell et al., 1989). For example, the eastern or California stock of the gray whale Eschrichtius robustus has apparently recovered from severe exploitation and thus was proposed for removal from the endangered species list by the U.S. Department of Commerce as of 7 January 1993 (Marine Mammal Commission, 1992). Some other marine mammals, such as the Gulf of California porpoise (vaquita) and the Yangtze River dolphin (baiji), appear to be headed for extinction. However, the majority of species are not endangered or seriously threatened.

Cetacea: Whales, Dolphins, Porpoises

The larger cetaceans include Physeteridae (sperm whales), Ziphoidea (beaked whales and bottlenose whales), and suborder Mysticeti (baleen whales) (Table B-1). Eight of the largest species are listed as endangered.

The sperm whale has been on the U.S. List of Endangered and Threatened Wildlife, even though there may be more than a million sperm whales in the world's oceans. Some specific populations are apparently depleted even though the world population is relatively large.

Because of their past exploitation by whalers and recent publicity about this exploitation, most large baleen whales are assumed by the public to be endangered species. However, in the absence of the

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

TABLE B-1 Classification of Living Mammals of the Order Cetacea

Suborder, family, genus, species

Common name

I. Suborder Odontoceti

 

Superfamily Platanistoidea

 

Family Platanistidae

 

Platanista gangetica

Ganges River dolphin, Ganges susu

Platanista minor *

Indus River dolphin, Indus susu

Family Pontoporiidae

 

Subfamily Lipotinae

 

Lipotes vexillifer * **

baiji, Yangtze, or Chinese River dolphin

Subfamily Pontoporiinae

 

Pontoporia blainvillei

franciscana, cachimbo, La Plata dolphin

Family Iniidae

 

Inia geoffrensis **

boto, boutu, bufeo, Amazon River dolphin

Superfamily Delphinoidea

 

Family Monodontidae

 

Subfamily Orcaellinae

 

Orcaella brevirostris

Irrawaddy dolphin, pesut

Subfamily Delphinapterinae

 

Delphinapterus leucas **

white whale, beluga

Subfamily Monodontinae

 

Monodon monoceros narwhal

 

Family Phocoenidae

 

Subfamily Phocoeninae

 

Phocoena phocoena **

harbor porpoise

Phocoena spinipinnis

Burmeister's porpoise

Phocoena sinus *

vaquita, Gulf of California harbor porpoise

Neophocaena phocaenoides

finless porpoise

Subfamily Phocoenoidinae

 

Australophocaena dioptrica

spectacled porpoise

Phocoenoides dalli

Dall's porpoise

Family Delphinidae

 

Subfamily Steninae

 

Steno bredanensis

rough-toothed dolphin

Sousa chinensis

Indopacific hump-backed dolphin

Sousa plumbea

plumbeous dolphin

Sousa teuszii

Atlantic hump-backed dolphin

Sotalia fluviatilis

tucuxi

Subfamily Delphininae

 

Lagenorhynchus albirostris

white-beaked dolphin

Lagenorhynchus acutus

Atlantic white-sided dolphin

Lagenorhynchus obscurus

dusky dolphin

Lagenorhynchus obliquidens

Pacific white-sided dolphin

Lagenorhynchus cruciger

hourglass dolphin

Lagenorhynchus australis

Peale's dolphin

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

Suborder, family, genus, species

Common name

Grampus griseus

Risso's dolphin

Tursiops truncatus

bottlenose dolphin

Stenella frontalis

Atlantic spotted dolphin

Stenella attenuata

pantropical spotted dolphin

Stenella longirostris

spinner dolphin

Stenella clymene

clymene dolphin

Stenella coeruleoalba

striped dolphin

Delphinus delphis

common dolphin

Lagenodelphis hosei

Fraser's dolphin

Subfamily Lissodelphinae

 

Lissodelphis borealis

northern right whale dolphin

Lissodelphis peronii

southern right whale dolphin

Subfamily Cephalorhynchinae

 

Cephalorhynchus commersonii

Commerson's dolphin

Cephalorhynchus eutropia

black dolphin, Chilean dolphin

Cephalorhynchus heavisidii

Heaviside's dolphin

Cephalorhynchus hectori

Hector's dolphin

Subfamily Globicephalinae

 

Peponocephala electra

melon-headed whale, electra dolphin

Feresa attenuata

pygmy killer whale

Pseudorca crassidens **

false killer whale

Orcinus orca **

killer whale

Globicephala melas

long-finned pilot whale

Globicephala macrorhynchus

short-finned pilot whale

Superfamily Ziphoidea.

 

Family Ziphiidae

 

Tasmacetus shepherdi

Shepherd's beaked whale

Berardius bairdii

Baird's beaked whale

Berardius arnuxii

Arnoux's beaked whale

Mesoplodon pacificus

Longman's beaked whale

Mesoplodon bidens

Sowerby's beaked whale

Mesoplodon densirostris

Blainville's beaked whale

Mesoplodon europaeus

Gervais' beaked whale

Mesoplodon layardii

strap-toothed whale

Mesoplodon hectori

Hector's beaked whale

Mesoplodon grayi

Gray's beaked whale

Mesoplodon stejnegeri

Stejneger's beaked whale

Mesoplodon bowdoini

Andrew's beaked whale

Mesoplodon mirus

True's beaked whale

Mesoplodon ginkgodens

ginkgo-toothed beaked whale

Mesoplodon carlhubbsi

Hubb's beaked whale

Ziphius cavirostris

Cuvier's beaked whale

Hyperoodon ampullatus

northern bottlenose whale

Hyperoodon planifrons

southern bottlenose whale

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

Suborder, family, genus, species

Common name

Superfamily Physeteroidea

 

Family Physeteridae

 

Subfamily Physeterinae

 

Physeter macrocephalus *

sperm whale

Family Kogiidae

 

Kogia breviceps

pygmy sperm whale

Kogia simus

dwarf sperm whale

II. Suborder Mysticeti

 

Family Balaenidae

 

Balaena mysticetus *

bowhead whale

Eubalaena austalis *

southern right whale

Eubalaena glacialis *

northern right whale

Family Neobalaenidae

 

Caperea marginata

pygmy right whale

Family Eschrichtfiidae

 

Eschrichtius robustus *1

gray whale

Family Balaenopteridae

 

Subfamily Balaenopterinae

 

Balaenoptera acutorostrata

minke whale

Balaenoptera borealis *

sei whale

Balaenoptera edeni

Bryde's whale

Balaenoptera musculus *

blue whale

Balaenoptera physalus *

fin whale, finback

Subfamily Megapterinae

 

Megaptera novaeangliae *

humpback whale

NOTE: * = endangered species; ** = species for which some audiometric information has been published.

1The California stock of gray whales has been recommended for delisting by NMFS.

resumption of full commercial whaling, most of these larger cetaceans, including some species of baleen whales that appear on the Endangered Species List are, as species, in reality not endangered. Some of these species have been completely protected for many years, and all are currently protected by the moratorium on commercial whaling promulgated by the International Whaling Commission. As with the sperm whales, however, some populations of large baleen whales remain depleted. Brownell et al. (1989) suggest that some of these large whales be removed from the Endangered Species List and that some small cetaceans be added. With the possible exception of the northern right whale, none of the large cetacean species is currently in peril of extinction (Perrin, 1988).

There are more than 40 species of smaller cetaceans, dolphins

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

and porpoises, found worldwide. While no cetacean species has been driven to extinction by human endeavors (Perrin, 1988), four species of the smaller cetaceans are in jeopardy in the coming decades if certain human activities in their habitats are not changed (Brownell, 1991; Norris, 1992). These include the baiji, Lipotes vexillifer; the Chilean dolphin, Cephalorhynchus eutropia; the Indus River dolphin, Platanista minor; and the vaquita, Phocoena sinus, of the Gulf of California.

The Carnivora: Pinnipeds, Sea Otters, Polar Bears

The marine Carnivora all spend some time on land or sea ice to breed and bear their young. The breeding areas are therefore especially sensitive to human encroachment. A few species live in freshwater. Marine mammals in the order Carnivora include fur seals and sea lions, true seals, walrus, chungungo and sea otters, and polar bears (Table B-2).

Pinnipedia

Pinniped means ''feather footed,'' and the suborder Pinnipedia includes three families: Otariidae (fur seals and sea lions), Odobenidae (walrus), and Phocidae (true seals). Historically, almost all pinnipeds were hunted for fur, meat, oil, or ivory. Brownell (1991) suggests that, although most pinniped species will probably experience an increase in number during the 1990s, at least three species—northern fur seal, Callorhinus ursinus; Steller sea lion, Eumetopias jubatus; and Mediterranean monk seal, Monachus monachus—will continue to decline in the absence of stronger corrective measures. One pinniped species, the Caribbean monk seal, Monachus tropicalis, has apparently become extinct during this century (Kenyon, 1977).

Sea Otters

The sea otter of the North Pacific, Enhydra lutris, is a coastal animal that is often associated with kelp beds just off the coasts of California, British Columbia, and Alaska.

The marine otter off the coasts of Peru and Chile, chungungo, Lutra felina, is severely endangered because the animals are hunted for their prized pelts on the Chilean coast and because Peruvians often shoot them as a menace to fishing (Miller and Rottmann, 1983). Another large otter, Lutra longicaudis of northeast Brazil, is threatened by fishing, clandestine hunting, and habitat degradation (Almeida et al., 1991).

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

TABLE B-2 Marine Mammals (Pinnipeds, Otters, Polar Bears) of the Order Carnivora

Family, genus, species

Common name

Family Otariidae of suborder Pinnipedia

 

Eumetopias jubatus

Steller sea lion, northern sea lion

Zalophus californianus **

California sea lion

Otaria flavescens

South American sea lion

Neophoca cinerea

Australian sea lion

Phocartos hookeri

New Zealand sea lion

Callorhinus ursinus **

northern fur seal

Arctocephalus townsendi *

Guadalupe fur seal

Arctocephalus philippii *

Juan Fernández fur seal

Arctocephalus galapagoensis

Galápalgos fur seal

Arctocephalus australis

South American fur seal

Arctocephalus pusillus

Cape fur seal, South African fur seal, Tasmanian fur seal, Victorian fur seal

Arctocephalus forsteri

New Zealand fur seal, West Australian fur seal

Arctocephalus gazella

Kerguelen fur seal, Antarctic fur seal

Arctocephalus tropicalis

Amsterdam Island fur seal

Family Odobenidae of suborder

 

Pinnipedia

 

Odobenus rosmarus

walrus

Family Phocidae of suborder

 

Pinnipedia

 

Phoca vitulina **

harbor seal

Phoca largha

larga seal, spotted seal

Phoca hispida **

ringed seal

Phoca sibirica

Caspian seal

Phoca groenlandica **

harp seal, Greenland seal

Phoca fasciata

ribbon seal

Erignathus barbatus

bearded seal

Cystophora cristata

hooded seal, bladdernose seal

Halichoerus grypus **

gray seal

Monachus monachus *

Mediterranean monk seal

Monachus tropicalis ***

West Indian monk seal, Caribbean monk seal

Monachus schauinslandi * **

Hawaiian monk seal

Mirounga leonina

southern elephant seal

Mirounga angustirostris

northern elephant seal

Lobodon carcinophagus

crabeater seal

Ommatophoca rossii

Ross seal

Hydrurga leptonyx

leopard seal

Leptonychotes weddelli

Weddell seal

Family Mustelidae

 

Lutra felina *

Chungungo, marine otter, gato marino

Enhydra lutris

sea otter

Family Ursidae

 

Ursus maritimus

polar bear

NOTES: The otters and bear listed in this table are regarded as marine mammals. Of course, most bears and otters are carnivores but not marine mammals.

* = endangered species; ** = species for which some audiometric data are available; *** = extinct species.

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

Polar Bears

Polar bears from the family Ursidae may be seen in the water some distance at sea. However, they spend most of the year on sea ice or, in the absence of ice, on land. They prey primarily on ringed seals (Phoca hispida). Polar bears also kill other marine mammals such as bearded seals (Erignathus barbatus), white whales (Delphinapterus leucas), and the narwhal (Monodon monoceros). Ringed seal populations are large, but white whales and narwhals, although not endangered,1 are much less numerous.

The Sirenia: Manatees and Dugongs (Sea Cows)

Although they receive much less attention by the media, the Sirenia are probably more endangered than any of the great whales with the possible exception of right whales. In fact, a sirenian species has become extinct in modern times (in the 1800s)—the great northern sea cow, or Steller's sea cow, Hydrodamalis gigas, of the Bering Sea (Nishiwaki and Marsh, 1985). Dugongs and manatees are the two living genera of Sirenia (Table B-3). They represent two distinct families of plant-grazing marine mammals that are found in separate parts of the world. Dugongs occur in tropical and subtropical shallows of the Indo-Pacific region—northern Australia, the Guangxi coast of China, Indonesia, the Aru Islands, Sri Lanka, India, the Persian Gulf, the Arabian Peninsula, the East African coast, and Madagascar.

Other than the dugong, the elephant and the hyrax are the closest living relatives of the manatee. There are three living species of

TABLE B-3 Living and Recent Members of the Totally Aquatic Order Sirenia (Sea Cows)

Family, genus, species

Common name

Order Sirenia (sea cows)

 

Family Dugongidae

 

Dugong dugon *

dugong

Hydrodamalis gigas ***

Steller's sea cow

Family Trichechidae

 

Trichechus manatus * **

Caribbean manatee

Trichechus inunguis *

Amazonian manatee

Trichechus senegalensis

West African manatee

NOTES: * = endangered species; ** = some auditory information is available; *** = extinct species.

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×

manatees: the West Indian or Florida manatee, Trichechus manatus; the West African manatee, T. senegalensis; and the Amazonian manatee, T. inunguis. Manatees prefer shallow estuaries and swampy areas where aquatic plants are abundant (Caldwell and Caldwell, 1985). They are at times found in freshwater, brackish water, or marine waters.

West Indian or Caribbean manatees range from Georgia on the coast of the southern United States to the coast of Brazil; however, there is a very patchy distribution over this wide range. The Amazonian manatee is found in the Amazon basin and possibly in parts of the Orinoco River system. The West African manatee is apparently most abundant in the Niger River and its tributaries (Nishiwaki et al., 1982), although there are areas of dense manatee population along the coast of Sierra Leone.

References

Almeida, R.T., G.P. Pimentel, and F.J.L. Silva. 1991. Occurrence of Otter Lutra longicaudis (Mammalia-Mustelidae) in mangrove area, Pernambuco State—NE Brazil. Abstract from: Ninth Biennial Conference on the Biology of Marine Mammals, Chicago Zoological Society, Chicago. p. 1.


Brownell, R.L., Jr. 1991. Marine Mammal Populations in the 1990's: Status, Problems and Research. IBI Reports. 2:1–10. (International Marine Biological Research Institute, Kamogawa, Japan.)

Brownell, R.L., Jr., K. Ralls, and W.F. Perrin. 1989. The plight of the 'forgotten' whales. Oceanus 32(1):5–11.


Caldwell, D.K., and M.C. Caldwell. 1985. Manatees, Trichechus manatus Linnaeus, 1758; Trichechus senegalensis Link, 1795 and Trichechus inunguis (Natterer, 1883). In: S.H. Ridgway and R.J. Harrison (eds.), Handbook of Marine Mammals, vol. 3. The Sirenians and Baleen Whales. Academic Press, London. pp. 33–66.


Kenyon, K.W. 1977. Caribbean monk seal extinct. J. Mammal. 58:97–98.


Marine Mammal Commission. 1992. Annual Report of the Marine Mammal Commission: Calendar Year 1991. A report to Congress. U.S. Marine Mammal Commission, Washington, DC.

Miller, S.D., and J. Rottmann. 1983. Endangered mammals of Chile: Status and conservation. Biol. Conserv. 25:335–352.


Nishiwaki, M., and H. Marsh. 1985. Dugong, Dugong dugon (Muller, 1776). In: S.H. Ridgway and R.J. Harrison (eds.), Handbook of Marine Mammals, vol. 3. The Sirenians and Baleen Whales. Academic Press, London. pp. 1–31.

Nishiwaki, M., M. Yamaguchi, S. Shikota, S. Uchida, and T. Kataoka. 1982. Recent survey on the distribution of African manatee. Sci. Rep. Whales Res. Inst. 34:137–147.

Norris, K. 1992. Dolphins in Crisis. Nat. Geog. 182(3):2–35.


Perrin, W. F. 1988. Dolphins, Porpoises, and Whales: An Action Plan for the Conservation of Biological Diversity: 1988–1992. IUCN, Gland, Switzerland.

Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
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Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 66
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 67
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 68
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 69
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 70
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 71
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
Page 72
Suggested Citation:"APPENDIX B AN INTRODUCTION TO MARINE MAMMALS." National Research Council. 1994. Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs. Washington, DC: The National Academies Press. doi: 10.17226/4557.
×
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This volume reviews the current state of knowledge regarding the effects of low-frequency sound on marine mammals and makes recommendations for research. In addition, the book describes current federal regulations prescribed under the Marine Mammal Protection Act that govern the taking of marine mammals by scientific research activities, and it recommends changes to expedite the regulatory process dealing with scientific research activities.

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