Duke Cherry Point PopUps 2005-2006 Bottlenose dolphin whistle presence
Duke University Marine Laboratory

Dataset credit

Duke University Marine Laboratory


Primary contact Andy Read Duke University
Data entry Melissa Soldevilla Duke University



Traditional marine mammal monitoring techniques, such as visual surveys, are not feasible under certain conditions, such as poor weather, darkness, and conflicts with other human activities. In such cases, alternative monitoring tools are required. We used autonomous acoustic recorders, designed by Cornell University, to monitor bottlenose dolphin (Tursiops truncatus) use of two ranges in Pamlico Sound, North Carolina, in which the United States Marine Corps conducts military training exercises. We deployed multiple units in the shallow waters of both ranges for more than a year. The recorders were programmed to sample at 12 kHz with a 12 kHz anti-aliasing filter. They were set on a duty cycle and of every hour, they recorded for either 10 or 30 consecutive minutes (bins of time referred to as “observation periods”). We analyzed the acoustic recordings using Raven 1.2.1 (Cornell Lab of Ornithology). We noted the presence or absence of dolphin whistles and clicks in each observation period to determine daily and seasonal patterns of dolphin occurrence in the two ranges. Vocalizing dolphins occurred frequently in both ranges throughout the year, with peaks of activity in June in both ranges and peaks in October, November, and December in one range. Vocalizing dolphins were detected more frequently in the late night and early morning hours than in the middle of the day and early night. We believe that such autonomous acoustic monitoring systems hold great promise for the management and mitigation of potentially adverse human activities on marine mammals.


The objective of this work was to address limitations of visual surveys in restricted ranges by conducting year-round monitoring of the presence of bottlenose dolphins in the Brant Island Shoal Bombing Target (BT-9) and the Piney Island Bombing Range (BT-11) using a passive acoustic monitoring system that could function during periods of darkness, poor weather, and on occasions when the ranges were in use.

Supplemental information

Observation dates and times are in GMT. Observations represent presence of whistles during a given duration observation period, either 10 or 30 minutes. Number of observations is the number of observation periods with whistles present. Number of animals is unknown and should not be inferred: a single individual may be represented by multiple observations and likewise a single observation period may include recordings from multiple individuals.


Read, R., L. Williams, K. Urian, D. Waples and T. Boynton. 2007. Acoustic monitoring of bottlenose dolphin use of the Brant Island Shoal Bombing Target (BT-9) and the Piney Island Bombing Range (BT-11). Final Report to Environmental Affairs Division, U.S. Marine Corps, MCAS Cherry Point.



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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
deploymentDeployment ID
latitudeInstrument Latitude
longitudeInstrument Longitude
obs_dateStart Date of observation GMT
obs_timeStart time of observation GMT
sp_obsSpecies observed
sp_tsnSpecies TSN code
obs_countPresence of dolphins whistles
recording_start_date_localStart Date of observation Local time
recording_start_time_localStart Time of observation Local time
recording_end_date_localEnd Date of observation Local time
recording_end_time_localEnd Time of observation Local time
gmt_diffTime difference between GMT and Local
dolphins_presentPresence or Absence of Dolphin whistles
fish_presentPresence or Absence of fish sounds
otherPresence or Absence of other noises
Marine mammals1,026
Sea turtles0
Rays and sharks0
Other species0
Non spatial0
Non species0
Date, Begin2005-03-22
Date, End2006-05-17
Temporal prec.111111
Latitude35.05 - 35.23
Longitude-76.47 - -76.43
Coord. prec.5 decimal digits
Data typeAcoustic - #call
EffortYES (ID: 569)
Sharing policy CC-BY-NC (Minimum)
Also availalbe from None
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