Analyses/Maps
Biogeography of Marine Mammals
Quick link to mammal chapter, Phase II
The California Current passes south through the study area off north/central California, which, along with areas of strong coastal upwelling, makes this area one of the most productive ocean systems in the world (Glantz and Thompson, 1981). Because of this productive environment, the study area contains a rich fauna of marine mammals, as evidenced in marine mammal abundance and species richness.
In addition to many marine mammal species that live here year-round and use the region's coasts and islands for breeding and hauling out, the community of seasonal residents and migrants is even more robust. Central California is the destination for many marine mammal species seeking productive feeding areas and acceptable habitat in which to spend their nonbreeding periods, providing evidence of the region's trophic richness. Over 29 species of marine mammals occur in the study area off north/central California; over 22 cetaceans (whales, dolphins, and porpoises), six pinnipeds (seals and sea lions), and one fissiped species (the sea otter).
The objectives of this assessment were to: 1) identify spatial and temporal distributions and patterns for marine mammals that occur in ocean waters off north/central California between Point Arena (38.91°N) and Pt Sal (34.90°N); 2) identify important finer-scale areas and time periods associated with higher concentrations of these species; and 3) identify important data and information gaps observed as a result of this analysis. In this analysis, "important" season or area refers to those having relatively higher concentrations of a particular species.
Table 4.1 below is a list of the mammal species included in the assessment, with links to PDF versions of maps and descriptions in the mammal chapter. Links to Tables 4.2 - 4.6 follow with summary information on the survey data used, population status, life history and management information and spatial and temporal patterns observed. Over 70 maps were developed for the mammal chapter; GIS files for some of the maps will be available at: http://ccma.nos.noaa.gov/products/biogeography/canms_cd/htm/data.htm
| Species Common Name (and stock name) or Map Name | Scientific Name(s) | Maps with CDAS Data |
Maps with Data from NOAA/ SWFSC |
Maps with Data from Other Sources1 |
Total No. of Maps per Species or Species' Stock |
PDF Map Description |
PDF Maps |
|---|---|---|---|---|---|---|---|
| Fissiped | |||||||
| Southern sea otter | Enhydra lutris nereis | 1 | 1 | Description 1 Description 2 |
Map 1 Map 2 |
||
| Pinnipeds | |||||||
| California sea lion | Zalophus californianus | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Steller sea lion | Eumetopias jubatus | 1 | 1 | 1 | Description | Map 1 | |
| Northern fur seal | Callorhinus ursinus | 4 | 1 | 4 | Description | Map 1 | |
| Pacific harbor seal | Phoca vitulina richardsi | 1 | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
| Northern elephant seal | Mirounga angustirostris | 1 | 1 | 1 | 1 | Description | Map 1 |
| Cetaceans | |||||||
| Dall's porpoise | Phocoenoides dalli | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Harbor porpoise (stocks: Northern CA, San Francisco/Russian River, Monterey Bay) | Phocoena phocoena | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Pacific white-sided dolphin | Lagenorhynchus obliquidens | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Risso's dolphin | Grampus griseus | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Bottlenose dolphin (CA coastal stock and CA/OR/WA stock) | Tursiops truncatus | 2 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
||
| Short-beaked common dolphin | Delphinus delphis | 1 | 1 | Description | Map 1 | ||
| Northern right whale dolphin | Lissodelphis borealis | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Killer whale | Orcinus orca | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Baird's beaked whale | Berardius bairdii | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Cuvier's beaked whale | Ziphius cavirostris | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Mesoplodont beaked whales | Mesoplodon spp. | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Sperm whale | Physeter macrocephalus | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Gray whale | Eschrichtius robustus | 4 | 1 | 5 | Description | Map 1 |
|
| Minke whale | Balaenoptera acutorostrata | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Fin whale | Balaenoptera physalus | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Blue whale | Balaenoptera musculus | 1 | 1 | 2 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Humpback whale | Megaptera novaeangliae | 4 | 1 | 5 | Description 1 Description 2 |
Map 1 Map 2 |
|
| Summary Mammal Maps | |||||||
| Summary of pinniped rookeries & haulouts | 1 | 1 | 1 | Description | Map 1 | ||
| Summary at-sea richness for pinnipeds | 1 | 1 | Description | Map 1 | |||
| Summary at-sea richness for cetaceans | 1 | 1 | Description | Map 1 | |||
| CDAS pinniped and cetacean effort map | 2 | 2 | Description | Map 1 | |||
| SWFSC ship tracks of survey effort | 1 | 1 | Description | Map 1 | |||
| TOTALS | 49 | 24 | 5 | 72 |
Notes
- Data sources other than SWFSC and CDAS are described in map sources and descriptions.
- New data were available for all Phase 2 CDAS mammal maps. At-sea data for SWFSC at-sea maps was the same as in Phase 1; all pinniped and haulout maps were updated from Phase 1, as well as the map for southern sea otter. The summary "at sea" richness and pinniped rookery/haulout maps are new in Phase 2.
- Table 4.2: Description of the Data Sets in the CDAS Mammal Data Set
- Table 4.3: Description of the Survey Effort in the CDAS Mammal Data Set
- Table 4.4: Summary Information on Mammal Life History and Management
- Table 4.5: Summary of Marine Mammal Population Estimates (2006)
- Table 4.6: Summary of Estimated Spatial and Temporal Occurrence for Selected Marine Mammals In Ocean Waters off North/Central California (original version)
| Species or Species and Stock | Occurrence in National Marine Sanctuaries (NMS)3,4 | Spatial Occurrence Over Bathymetric Zones in the Study Area3,4,5,6 | Temporal Occurrence in Study Area3,4,5,6,7 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Cordell Bank NMS |
Gulf of Farallones NMS |
Monterey Bay NMS |
Nearshore (Coast to 50m isobath) |
Inner Continental Shelf (coast to 100m isobath) |
Outer Continental Shelf (100m–200m isobaths) |
Continental Slope (200m– 2,000m isobaths) |
Deep Ocean, beyond the Slope (>2000m isobath) |
Upwelling Season (3/15-8/14) |
Oceanic Season (8/15-11/14) |
Davidson Current Season (11/15-3/14) |
|
| Southern sea otter * | NS | NS | C/F | C/F | R/U | NS | NS | NS | C/F | C/F | C/F |
| California sea lion * | C/F | C/F | C/F | C/F | C/F | R/U | R/U | R/U | C/F | C/F | C/F |
| Steller sea lion * | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | |
| Northern fur seal * | C/F | C/F | C/F | R/U | R/U | C/F | C/F | C/F | C/F | R/U | C/F |
| Pacific harbor seal * | R/U | C/F | C/F | C/F | C/F | R/U | NS | NS | C/F | C/F | C/F |
| Northern elephant seal * | R/U | C/F | C/F | R/U | R/U | C/F | C/F | R/U | R/U | R/U | R/U |
| Bottlenose dolphin, CA coastal stock ** |
NS | R/U | R/U | R/U | R/U | NS | NS | R/U | R/U | R/U | |
| Harbor porpoise (central CA) ** |
R/U | C/F | C/F | C/F | C/F | R/U | NS | NS | R/U | R/U | R/U |
| Dall's porpoise | C/F | C/F | C/F | R/U | R/U | C/F | C/F | C/F | C/F | C/F | C/F |
| Risso's dolphin | C/F | C/F | C/F | NS | R/U | C/F | C/F | C/F | C/F | C/F | C/F |
| Pacific white-sided dolphin | C/F | C/F | C/F | NS | R/U | C/F | C/F | C/F | C/F | C/F | C/F |
| Short-beaked common dolphin | NS | R/U | R/U | R/U | R/U | R/U | C/F | C/F | R/U | R/U | R/U |
| Northern right-whale dolphin | C/F | C/F | C/F | NS | NS | R/U | C/F | C/F | C/F | C/F | R/U |
| Killer whale | R/U | R/U | C/F | R/U | R/U | R/U | C/F | R/U | C/F | C/F | C/F |
| Baird's beaked whale | R/U | R/U | R/U | NS | NS | NS | R/U | R/U | R/U | R/U | R/U |
| Cuvier's beaked whale | R/U | R/U | R/U | NS | NS | NS | R/U | R/U | R/U | R/U | R/U |
| Other beaked whales: Mesoplodont spp. | R/U | R/U | R/U | NS | NS | R/U | R/U | NS | R/U | NS | |
| Sperm whale | R/U | R/U | R/U | NS | NS | R/U | R/U | R/U | R/U | R/U | R/U |
| Blue whale | R/U | R/U | R/U | R/U | R/U | C/F | C/F | R/U | C/F | C/F | R/U |
| Humpback whale | C/F | C/F | C/F | C/F | C/F | C/F | C/F | R/U | C/F | C/F | R/U |
| Fin whale | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U | R/U |
| Minke whale | R/U | C/F | C/F | C/F | C/F | R/U | R/U | R/U | R/U | C/F | R/U |
| Gray whale | R/U | C/F | C/F | C/F | C/F | R/U | R/U | NS | C/F | R/U | C/F |
| NS or no tone | Not sighted or 1-2 total sightings in available data sets; see below. |
| R/U | Present; sightings were mostly Rare or Uncommon at sea (e.g., sightings occurred once a month to once a year) |
| C/F | Present; sightings were mostly Common or Frequent at sea (e.g., sightings occurred almost daily to every few weeks) |
* Indicates breeding occurs in the study area.
** Indicates breeding likely occurs in study area.
Notes:
- The intent of this table is to provide a summary of where and when marine mammals occur in the study area off north/central California, from Pt. Arena to Pt. Sal. This table was developed in spring-summer 2007, and is based on a combination of expert opinions (see below) and the following sources: the CDAS central CA data set (1980-2003), the NOAA/SWFSC mammal surveys (1991-2001), NMFS stock assessment reports (e.g., Caretta et al., 2006), information from the Monterey Bay Whale watch site (http://www.gowhales.com/sighting.htm), and current sanctuary management plans.
- This table was developed in 2006 by Tracy Gill (NCCOA NOAA) and Carol Keiper (Oikonos) and reviewed and revised by David Ainley, John Calambokidis, Jan Roletto, Sarah Allen and Lisa Etherington.
- Species may occur in the study area in areas and time periods not indicated; the absence of sightings may be due to insufficient survey effort than real absence from the area or season.
- This table does not attempt to address relative abundance; it does contain a qualitative estimate of frequency of sightings in the study area. Frequency of sightings can vary annually and interannually. For example, a species can generally be considered rare in a certain location or time period, but occasionally occur in that place o time with common or frequent sightings.
- The study area includes the ocean waters off north/central California, from Pt. Arena to Pt. Sal, CA, and offshore to the extent of data (~35-39°N x 120-130°W).
- When different opinions were offered by researchers as to whether a species was not sighted or sighted (no tone or light) we chose to show the species as Present, rare/uncommon. If the difference was deciding between the lower and higher categories of sightings based on two sources, we chose the dark tone.
- Species may have been sighted in the study area in all three seasons, but may not be considered year-round, as some species move out of the study area for part of the year for feeding or breeding.