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Updated Number of Marine Mammal Species

Humpback whale breaching in the early morning off the coast of Big Sur. Photo by Dr. Steve Lonhart, NOAA MBNMS.

Monterey Bay National Marine Sanctuary is referred to some as the “Serengeti of the Sea” due to the large number of marine mammals living in or swimming through sanctuary waters. This summer, undergraduate intern Katie Rice from UC Berkeley tackled a tall task in determining the number of species occurring in the sanctuary.

Katie, with guidance from local scientists, developed a process that could be used to determine the number of species found in any sanctuary.  Part of this involved using existing online databases, published records, expert opinion, and local observations.  For some groups (or Phyla), such as the Mollusca, this is a daunting task since at least 85,000 species are currently recognized globally, and there are likely well over 1,000 molluscs in the sanctuary.

For other groups, like marine mammals (subset of Class Mammalia, in Phylum Chordata), the task is much more manageable due to low numbers of species that live in or transit through the sanctuary, as well as the large size of these animals and their beloved status by the public.  Sightings data are much more common, and there are extensive programs that monitor the health of marine mammal populations.  Several marine mammal species are either threatened or endangered, and there are ongoing efforts to restore these populations.

In spite of the relatively manageable number of marine mammals, there remain questions about whether to count a species that resides in the sanctuary or simply is passing through.  For the purposes of this updated list of marine mammals in Monterey Bay NMS, we decided to rely on species sightings as the minimum criterion.  Below is a list of 36 marine mammals observed in Monterey Bay NMS:

Common name Genus species Comment
Baird’s beaked whale Berardius  bairdii
Blainville’s beaked whale Mesoplodon densirostris Rare
Blue whale Balaenoptera  musculus  Uncommon
Bottlenose dolphin Tursiops  truncatus
Bryde’s whale Balaenoptera edeni Rare
California gray whale Eschrichtius  robustus
California Sea Lion Zalophus californianus
Cuvier’s beaked whale Ziphius  cavirostris  Uncommon
Dall’s porpoise Phocoenoides  dalli
Dwarf sperm whale Kogia  sima  Uncommon
False killer whale Pseudorca  crassidens Rare visitors during warm water events in Monterey Bay
Fin whale Balaenoptera  physalus
Guadalupe Fur Seal Arctocephalus townsendi  Uncommon
Harbor porpoise Phocoena phocoena
Harbor Seal Phoca vitulina
Hubbs’ beaked whale Mesoplodon  carlhubbsi  Uncommon
Humpback whale Megaptera  novaeangliae
Killer whale Orcinus  orca
Lesser beaked whale Mesoplodon peruvianus Rare; stranding in Monterey Bay
Long-beaked common dolphin Delphinus  delphis bairdii This species was recently returned to subspecies status, pending further review. It is now considered Delphinus delphus bairdii.
Minke whale Balaenoptera  acutorostrata
Northern Elephant Seal Mirounga angustirostris
Northern Fur Seal Callorhinus ursinus
Northern right whale dolphin Lissodelphis  borealis
North Pacific right whale Eubalaena  japonica
Pacific white-sided dolphin Lagenorhynchus  obliquidens
Pygmy sperm whale Kogia  breviceps  Uncommon
Risso’s dolphin Grampus  griseus
Sei whale Balaenoptera  borealis  Uncommon
Short-beaked common dolphin Delphinus  delphis delphis
Short-finned pilot whale Globicephala  macrorhynchus  Uncommon
Southern sea otter Enhydra lutris nereis
Sperm whale Physeter  macrocephalus  Uncommon
Stejneger’s beaked whale Mesoplodon stejnegeri Rare
Steller Sea Lion Eumetopias jubatus  Uncommon
Striped dolphin Stenella  coeruleoalba Found very far off shore

This list was reviewed by Dr. Karin Forney, a NOAA scientist who has, since 1987, conducted research on the abundance, distribution, ecology, and status of over 25 species of cetaceans (whales, dolphins and porpoises) in the eastern and central North Pacific Ocean, with emphasis on small cetaceans.  The list was also reviewed by Dr. Jim Harvey, Professor of Vertebrate Ecology and current Director of Moss Landing Marine Laboratories.  Since the mid-1970s Dr. Harvey has studied the ecology, morphology, and behavior of marine mammals, birds, and turtles; used VHF/satellite-telemetry; investigated marine mammal/fisheries interactions; developed vertebrate sampling techniques and experimental design; tracked population and trophic dynamics; and conducted marine mammal stranding studies.

How many will you see during a whale watching cruise?  Over the course of a year, 20 species sighted is typical, but on any individual cruise it could be much less, depending on the time of year, ocean conditions, and where the vessel is located.

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