https://doi.org/10.82144/e0a2efa8 https://seamap.env.duke.edu/dataset/40 https://www.gbif.org/dataset/96fae9be-8455-4015-b447-a00f935e8e77 https://obis.org/dataset/01e6c76e-cdd1-4da3-b3e1-861ea4bad3ed Janet Casey Janet Casey Primary contact unknown@dummy.com Glenn Ford Glenn Ford Primary contact eci@teleport.com OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu distributor Janet Casey Janet Casey Primary contact unknown@dummy.com owner Glenn Ford Glenn Ford Primary contact eci@teleport.com owner 2025-07-31 eng Original provider: Minerals Management Service Dataset credits: Minerals Management Service Abstract: This dataset is from the marine mammal and seabird surveys of central and northern California studies: Central/northern California - high aerial [Cetaceans] study Code: CH, Contract number: 14-12-0001-29090, Principal investigator: Thomas P. Dohl, Center for Marine Studies, University of California, Santa Cruz Study area: Shelf, slope, and offshore waters to a distance of 100 nm off the California coast from Point Conception to the California-Oregon boundary. Methodology: Offshore transect surveys were flown twice-monthly at two different altitudes (200 ft and about 750-1,000 ft ASL) along approximately 40 east-west transect lines extending an average of 60 nm offshore. The transects sampled on a given survey were selected randomly from a set of 92 standard (predetermined) lines spaced at intervals of 5' of latitude. Standard transects provided systematic coverage of shelf, slope, and offshore waters in the study area. Sightings of seabirds, pinnipeds, and sea otters were recorded only on low-altitude surveys. Sightings of cetaceans and turtles were recorded on both low- and high-altitude surveys. Seabird sightings were recorded only on the shaded side of the aircraft within a strip transect of 50 m width. Marine mammal and turtle sightings were recorded within an unbounded corridor on both high- and low-altitude surveys, but only the shaded side of the aircraft was searched on the low-altitude surveys. Cross-legs connecting standard transects were searched only on high-altitude surveys. Offshore cross-legs were searched on both sides of the aircraft, while only the nearshore side was searched on cross-legs along the coast. Declination angle was measured and noted for each marine mammal/turtle sightings and later used to calculate a probability density function of frequency with right-angle sighting distance. Navigation was by Loran and VLF-Omega. Databases produced: Three databases of sightings at sea were produced by these studies (data on numbers of seabirds and pinnipeds on land were also collected but are not addressed in the present study). These include: 1) sightings of cetaceans and turtles recorded on 36 high-altitude aerial surveys, 2) sightings of cetaceans, pinnipeds, sea otters, and turtles recorded on 36 low-altitude aerial surveys, and 3) sightings of seabirds on 36 low-altitude aerial surveys. Each sighting database is accompanied by files providing the search effort on transect and environmental characteristics of the waters surveyed (e.g., sea surface temperature). Occurrence GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml Marine Biology Visual sighting Marine Animal Survey Marine mammals Sea turtles Vessel Visual Sighting N/A This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0 License. https://seamap.env.duke.edu/dataset/40 Oceans,Northeastern Pacific Ocean -125.9708 -117.213 43.3746 27.5203 1980-03-10 1983-02-16 Scientific names are based on the Integrated Taxonomic Information System (ITIS). species Balaenoptera acutorostrata Common minke whale species Balaenoptera borealis Sei whale species Balaenoptera musculus Blue whale species Balaenoptera physalus Fin whale species Berardius bairdii Baird's beaked whale species Callorhinus ursinus Northern fur seal order Cetacea Cetaceans species Dermochelys coriacea Leatherback sea turtle species Enhydra lutris Sea otter species Eschrichtius robustus Gray whale species Globicephala melas Long-finned pilot whale species Grampus griseus Risso's dolphin genus Kogia Pygmy sperm whales species Lagenorhynchus obliquidens Pacific white-sided dolphin species Lissodelphis borealis Northern right whale dolphin species Megaptera novaeangliae Humpback whale genus Mesoplodon Beaked whales species Mirounga angustirostris Northern elephant seal species Orcinus orca Killer whale family Otariidae Eared seals species Phocoena phocoena Harbor porpoise species Phocoenoides dalli Dall's porpoise species Physeter macrocephalus Sperm whale species Ziphius cavirostris Cuvier's beaked whale To determine species composition, distribution, abundance, and seasonal variation for marine mammal and seabird populations, provide a description of habitat use, and identify areas of special biological importance to these populations in the central and northern California study area. notPlanned Janet Casey Janet Casey Primary contact unknown@dummy.com Glenn Ford Glenn Ford Primary contact eci@teleport.com NA NA NA Janet Casey owner Glenn Ford owner NA zd_40 2025-07-31T14:02:49-04:00 dataset Ford, G. and J. Casey. 2013. MMS High Altitude Survey 1980-1983. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/e0a2efa8. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/40 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/40/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/40/eml OBIS-SEAMAP zd_40 zd_40 Bonnell, M. L., M. O. Pierson, and G. D. Farrens. 1983. Pinnipeds and sea otters of central and northern California, 1980-1983: Status, abundance, and distribution. Part of Investigator's Final Report, Marine Mammal and Seabird Study, Central and Northern California, Contract No. 14-12-0001-29090. Prepared by Center for Marine Sciences, University of California, Santa Cruz, for the Pacific OCS Region, Minerals Management Service: OCS Study MMS 84-0044. 220 pp.