Marine mammal aerial surveys in the Bering, Chukchi and Beaufort Seas 1979-2010
National Marine Mammal Laboratory

Dataset credit

National Marine Mammal Laboratory


Primary contact Megan Ferguson Cetacean Assessment and Ecology Program, National Marine Mammal Laboratory
Data entry Connie Kot Duke University



The Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE), formerly the Minerals Management Service (MMS), and its precursor, the Bureau of Land Management, have funded aerial surveys in the Beaufort, Chukchi and Bering Seas since 1979. In 2008, through an Inter-Agency Agreement between BOEMRE and the National Marine Mammal Laboratory (NMML) (Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration), NMML assumed full responsibility for these surveys. Consistent survey protocol has been in effect on surveys conducted since 1982.

Aerial surveys in the western Beaufort Sea (south of 72 degrees N, 140-157 degrees W) have been conducted each year since 1979. MMS (now BOEMRE) personnel and contractors conducted the surveys from 1979-2007. From 2008-2010, the surveys were conducted by NMML. The goal of the project, also known as the Bowhead Whale Aerial Survey Project (BWASP), was to document bowhead whales (Balaena mysticetus) during their fall migration through the western Beaufort Sea, although data were also collected for all other marine mammals that were sighted during the surveys. The surveys were typically conducted during the open water (i.e., ice-free) months of September and October, when offshore drilling and geophysical exploration are feasible and when the fall subsistence hunt for bowhead whales takes place near Kaktovik, Cross Island (village of Nuiqsut), and Barrow, Alaska. Additional surveys were conducted in the Beaufort Sea during spring and summer 1979-1986. The emphasis of fall surveys in the Beaufort Sea was to conduct broad-scale surveys to assess shifts in the migration pathway of bowhead whales, and to coordinate effort and manage data necessary to support seasonal offshore drilling and seismic exploration regulations. The selection of survey blocks to be flown on a given day was nonrandom, based primarily on criteria such as observed and predicted weather conditions over the study area and offshore oil industry activities. Otherwise, the project attempted to distribute effort fairly evenly east-to-west across the entire study area. Aerial coverage favored inshore survey blocks because bowheads were rarely sighted north of these blocks during surveys conducted from 1979-1986.

Aerial surveys in the northeastern Chukchi Sea (68-73 degrees N, 157-169 degrees W) were conducted by MMS (now BOEMRE) contractors from 1982-1991. From 2008-2010, the surveys were conducted by NMML using similar methodology to the surveys conducted in previous years. The goal of the surveys, now known as the Chukchi Offshore Monitoring in Drilling Area (COMIDA) marine mammal aerial survey project, was to investigate the distribution and relative abundance of marine mammals in the Chukchi Sea Planning Area (CSPA) during the open water (i.e., ice-free) months of June to October, when various species are undertaking seasonal migrations through the area. However, from 1979-1984, surveys were also conducted during spring.

Aerial surveys in the northern Bering and southern Chukchi Seas (63-68 degrees N, east of the International Date Line) were conducted by MMS (now BOEMRE) contractors from 1979-1985. The goal of these surveys was to investigate the distribution, abundance, migration timing, habitat relationships and behavior of endangered whales during the spring migration. Surveys were conducted from April-July. This database contains aerial survey data from the surveys described above.


The goals of the Bowhead Whale Aerial Survey Project (BWASP) have changed minimally since the surveys commenced in 1979. Objectives of the surveys since the late 1980s were to 1) Define the annual fall migration of bowhead whales, significant inter-year differences, and long-term trends in the distance from shore and water depth at which whales migrate, 2) Monitor temporal and spatial trends in the distribution, relative abundance, habitat, and behaviors (especially feeding) of endangered whales in arctic waters, 3) Provide real-time data to MMS and the National Marine Fisheries Service (NMFS) on the general progress of the fall migration of bowhead whales across the Alaskan Beaufort Sea for use in protection of this endangered species, 4) Provide an objective wide area context for management interpretation of the overall fall migration of bowhead whales and site-specific study results, 5) Record and map beluga whale distribution and incidental sightings of other marine mammals, 6) Determine seasonal distribution of endangered whales in other planning areas of interest to BOEMRE.

The goals of the Chukchi Offshore Monitoring in Drilling Area (COMIDA) marine mammal aerial survey project commencing in 2008 were to 1) Provide data compatible with the MMS marine mammal database directly to MMS for inclusion in that database and for use in estimation of the distribution of cetaceans and pinnipeds in the CSPA from 3 surveys during June-November, 2) Document geographical areas of importance for specific behaviors including calving/pupping, feeding, hauling-out, and migrating, 3) Provide timely information on marine mammal observations and environmental conditions, including ice conditions, following each survey flight to organizations as directed by the COR (e.g., National Ice Center, National Marine Fisheries Service, Alaska Eskimo Whaling Commission, MMS) for real-time management of activities in the region.

The goals of the surveys conducted in the northern Bering and southern Chukchi Seas from 1979-1985 were to, 1) Determine seasonal distribution, migration routes, relative abundance, and habitat characteristics of endangered whales in or near existing proposed federal lease sales in the northern Bering, Chukchi and Beaufort Seas, 2) Derive estimates and indicators of relative and/or absolute abundance of endangered whales in these areas, 3) Describe behavioral characteristics of endangered whales observed in these areas, 4) Deploy sonobuoys to detect sounds produced by whales, to be used as additional indices of whale presence in these areas, 5) Obtain distributional information on non-endangered marine mammal sightings incidental to other investigations, 6) Consult and coordinate field activities with other federal agencies, state or local government organizations, or other endangered species researchers to maximize productivity of this study and minimize conflict with other resource uses.

Supplemental information

Access and availability of data collected from the Bowhead Whale Aerial Survey Project (BWASP) and Chukchi Offshore Monitoring in Drilling Area (COMIDA) marine mammal aerial survey project are found online here.

Information presented on this website is considered public information and may be distributed or copied. However, as a professional courtesy, and to prevent duplication of, or more efficient coordination with, any ongoing analyses, please email Dr Megan Ferguson ( if there is an intention to use these data in a scientific report, whether published or not. Credit should be given for use (including any summaries, maps, or images) of these data; please ask Dr Ferguson for the appropriate credits relative to the intended use. These data undergo periodic updates as new data become available or existing data are edited for accuracy and consistency. Therefore, we recommend citing the version number whenever these data are used. We also recommend that these data be acquired directly from the NMML server and not through other sources that might not have the most recent version.


Clarke, J.T., Christman, C.L., Brower, A.A., Ferguson, M.C., and Grassia, S.L. 2011. Aerial surveys of endangered whales in the Beaufort Sea, Fall 2010. Annual Report. OCS Study BOEMRE 2011-035.
Clarke, J.T., Ferguson, M.C., Christman, C.L., Grassia, S.L., Brower, A.A., and Morse, L.J. 2011. Chukchi Offshore Monitoring in Drilling Area (COMIDA) distribution and relative abundance of marine mammals: aerial surveys. Final Report. OCS Study BOEMRE 2011-06.



Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downlodable online. Other attributes may be obtained upon provider's permission unless otherwise noted below.

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes in dataset provided

Attribute (table column)Description
oidUnique ID (generated by OBIS-SEAMAP)
recidRecord ID (generated by OBIS-SEAMAP)
origidID number
eventEvent number
flt_noFlight number
obs_timeTime of observation at local time zone (8 hours behind Greenwich Mean Time)
obs_dateDate of observation
latoriginOriginal latitude
lonoriginOriginal longitude
arclatArc latitude
arclongArc longitude
air_headAircraft Heading
entryReason for entering a new record
sp_obsSpecies observed
sp_tsnSpecies ITIS TSN
sightcueSighting Cue
habitatHabitat of sighting
behaviorBehavior of sighting
totalnoInitial group size estimate
finalgrpFinal group size estimate
obs_countNumber of animals
lowestMinimum group size estimate
highestMaximum group size estimate
calfnoTotal number of calves or pups observed
calfoncircNumber of calves or pups observed while circling the sighting
clinometerAngle of declination from horizon to sighting
sopSide of plane on which sighting was observed
swimdirDirection animal was swimming
swimspeedSwim speed (categorical)
responseWhether animal appeared to respond to survey aircraft
repeatWhether the sighting was a repeat
observerName of observer who made the sighting
skyconSky conditions
visimpleftImpediment to visibility on left side of aircraft
visimprtImpediment to visibility on right side of aircraft
vis_leftVisibility range (km) on left side of aircraft
vis_rightVisibility range (km) on right side of aircraft
icepercentPercent ice cover
icetypeType of ice precent
seastateBeaufort Sea State
blockBlock number
depth_mdepth of sea floor (m)
aersurveySurvey descriptor
swimdirtDirection animal was swimming
magvar_gpsMagnetic variation data from gps
magvar_dirMagnetic variation direction
airheadgpsAircraft heading from gps
calfdetctCertainty with which a calf that is present would be detected
group_definition not provided
savedWhether the record was was valid and saved, or should be ignored
flttypeTied to Entry field
transectidID of transect
familyNumeric code for grouping related species together
enttagTied to Entry field
xofwhaleLongitude of whale (calculated)
yofwhaleLatitude of whale (calculated)
latitudeLatitude of sighting
longitudeLongitude of sighting
distshoreDistance to shore
datarecordName of data recorder
obsleftName of left primary observer
obsrightName of right primary observer
obsfourthName of 4th observer
phototakenWhether a photo was taken of the event
lattempEquals yofwhale, if present; otherwise, equals arclat
longtempEquals xofwhale, if present; otherwise, equals arclong
geomGeometry field added by OBIS-SEAMAP
Marine mammals25,488
Sea turtles0
Rays and sharks0
Other species24
Non spatial0
Non species0
Date, Begin1979-04-23
Date, End2010-10-25
Temporal prec.111111
Latitude58.06 - 75.25
Longitude-172.84 - -126.36
Coord. prec.6 decimal digits
Data typeAnimal sighting
EffortYES (ID: 826)
Traveled (km)1,451,008
Effort hours6,486
Sharing policy CC-BY-NC (Minimum)
Also availalbe from iOBIS
See metadata in static HTML
See metadata in FGDC XML
See download history / statistics