SIO Southern California HARPs Acoustic Dolphin Detections 2005-2007

John Hildebrand

Dataset credit

These data were analyzed by Melissa Soldevilla. This research project was funded by F. Stone and E. Young through CNO-N45.


Primary contact John Hildebrand Scripps Institution of Oceanography, University of California, San Diego
Data entry Melissa Soldevilla Duke University



High-frequency Acoustic Recording Packages (HARPs) were deployed at six locations in the Southern California Bight between August 2005 and January 2008 to examine diel, seasonal, and annual patterns of occurrence and distribution. Long term spectral averages (LTSAs) were examined by eye for the presence of echolocation click bouts from Risso's dolphins and Pacific white-sided dolphins. Click bouts were identified to species by a trained analyst based on their spectral characteristics (described in Soldevilla et al 2008). Observations represent presence in one-hour time bins (#obs) and are quantified as the number of one-minute time bins with clicks present. Two click types, A and B, were identified for Pacific white-sided dolphins, which show spatial and temporal segregation in occurrence. HARP recording schedules varied across deployments and include continuous recording, 1/2, 1/3, and 1/4 duty cycles in which 5 minutes were recorded followed by 5, 10, and 15 minutes off, respectively. Effort data is also available in one-hour time bins and includes the number of minutes with recording effort per hour.


The goal of this work was to monitor occurrence of acoustically active cetaceans in the Southern California Bight and develop predictive models of habitat. The data presented here are based on echolocation clicks of Risso's dolphins and Pacific white-sided dolphins.

Supplemental information

Times are in GMT.




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

Attributes in dataset

Attribute (table column)Description
obs_dateDate of observation GMT
obs_timeTime of observation GMT (in 1 hour increments)
obs_countNumber of minutes with clicks present
latitudeInstrument Latitude
longitudeInstrument Longitude
mean_depthInstrument Depth (m)
depth_st_devDepth standard deviation (m) (varied across deployments)
sp_tsnSpecies ID code
sp_obsSpecies observered and call type
site_idSite ID code
Marine mammals4,651
Sea turtles0
Rays and sharks0
Other species0
Non spatial0
Non species0
Date, Begin2005-08-14
Date, End2008-01-02
Temporal prec.111100
Latitude32.65 - 34.31
Longitude-120.80 - -118.25
Coord. prec.6 decimal digits
Data typeAcoustic - #call
EffortYES (ID: 534)
Traveled (km)0
Travel hours45,389
Contr. through
Sharing policy CC-BY-NC (Minimum)
Shared with None
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