Gray whale Infrared blow detections from shore 2015
Regina A. Guazzo, Scripps Institution of Oceanography

Dataset credit

National Oceanic and Atmospheric Administration, Southwest Fisheries Science Center

Contacts

RoleNameOrganization 
Primary contact Regina Guazzo Scripps Institution of Oceanography
Data entry Ei Fujioka Duke University

Citation

Guazzo, R. A., Weller, D. W., Europe, H. M., Durban, J. W., D\'Spain, G. L., and Hildebrand, J. A. in review. Migrating eastern North Pacific gray whale cue rates estimated from acoustic recordings, infrared images, and visual sightings. Scientific Reports.

Abstract

During the eastern North Pacific gray whale 2014–2015 southbound migration, acoustic call recordings, infrared blow detections, and visual sightings were combined to estimate cue rates, needed to convert detections into abundance. The gray whale M3 acoustic call rate was 2.3–24 calls/whale/day with an average of 7.5 calls/whale/day over the entire migration (southbound and northbound) and showed a positive trend from 30 December–13 February. The infrared camera blow rate averaged 49 blows/whale/hour over 5–8 January. With a call rate model, we estimated that 4,340 gray whales migrated south before visual observations began on 30 December, which is 2,829 more gray whales than used in the visual abundance estimate. This finding highlights the usefulness of cue rates to increase precision in abundance estimates. We suggest that visual observers increase their survey effort to all of December to verify gray whale abundance corrections. Probability of detection of a whale blow by the infrared camera was the same at night as during the day. However, probability of detection decreased beyond 2.1 km offshore, whereas visual sightings revealed consistent whale densities up to 3 km offshore. We suggest that future infrared camera surveys use multiple cameras optimized for different ranges offshore.

Purpose

N/A

Supplemental information

Infrared camera located at 36 26' 24.61" N 121 55'19.41"W

"Effort" tab gives the start and end times of each infrared video in Julian Date, Matlab datenum format: Days since Jan 0, 0000. Note that there are short gaps between videos.

The original datasheet is included in the downloadable zipped file.

References

Guazzo, R. A., Weller, D. W., Europe, H. M., Durban, J. W., D\'Spain, G. L., and Hildebrand, J. A. in review. Migrating eastern North Pacific gray whale cue rates estimated from acoustic recordings, infrared images, and visual sightings. Scientific Reports.

Attributes

Overview

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 number (generated by OBIS-SEAMAP)
speciesSpecies name recorded
sp_tsnTaxonomic Serial Number added by OBIS-SEAMAP
utc_timeJulian Time in Matlab datenum format, UTC time zone
local_timeJulian Time in Matlab datenum format, PST time zone
datetimeDate and time in local time zone converted from local_time
datetime_utcDate and time inUTC converted from utc_time
latitudeLatitude in decimal degrees
longitudeLongitude in decimal degrees
rangeRange offshore in km
azimuthAzimuth to whale blow
obs_countdefinition not provided
geomGeometry field added by OBIS-SEAMAP
OBIS-SEAMAP ID1864
Seabirds0
Marine mammals1,882
Sea turtles0
Rays and sharks0
Other species0
Non spatial0
Non species0
Total1,882
Date, Begin2015-01-05
Date, End2015-01-08
Temporal prec.111111
Latitude36.42 - 36.44
Longitude-121.98 - -121.93
Coord. prec.6 decimal digits
PlatformShore
Data typeAnimal sighting
EffortN/A
Registered2018-06-28
Updated2019-04-01
StatusPublished
Sharing policy CC-BY-NC (Minimum)
Also availalbe from iOBIS
GBIF (planned)
See metadata in static HTML
See metadata in FGDC XML
See download history / statistics
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