Sargasso 2005 - cetacean sightings
Dalhousie University

Dataset credit

Hal Whitehead, Department of Biology, Dalhousie University


Primary contact David Hyrenbach Duke University Marine Laboratory
Primary contact Hal Whitehead Dalhousie University
Data entry Ei Fujioka Duke University



The Sargasso Sea cruise surveyed marine mammals in the Northeast Atlantic Ocean, during the spring and summer of 2005. This survey onboard the Valiant 40 ocean-going research vessel Balaena, consisted of two survey legs: a sail from the Caribbean to offshore waters north of the Bahamas (April 19 - June 2), and a sail north to Halifax, Nova Scotia. Sperm whales were surveyed using acoustics and visual techniques during both cruise legs by members of the Hal Whitehead laboratory.


The purpose of this cruise was to study the behavior (principally social organization), ecology, and population biology of sperm whales. This is the second study year, after a similar cruise in the summer of 2004.

Supplemental information

This dataset includes cetacean observations and survey effort. The survey track was recorded by logging a position every 10 minutes using the vessel's GPS. The cetacean observations includes sightings during surveys (on effort) and during focal follows of sperm whale schools (off effort).

There are two types records for sperm whale, census and encounter. Encounters, which are defined as events where researchers observe whales by sight or acoustic techniques, are denoted 'S' (survey), 'E' (encounter), or 'AE' (acoustic encounter) in the [Enctr_type] field. These records do not have animal counts recorded, and count field for these records is null in the dataset.

In addition to encounters, this dataset includes sightings during 'census' surveys, which include group size data, as well as information on the radial distance and angle to each sighting. These survey metadata are available from the primary data providers.

Census records have non-zero animal counts as for other species. They are denoted C in [Enctr_type] field.
Note that the [Enctr_type] field is not downloadable by the public, but may be available by request. Please request this data after obtaining permission from the primary data providers.




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.

Attributes in dataset provided

Attribute (table column)Description
cruise_legCruise leg
dayDay of observation
monthMonth of observation
yearYear of observation
hourIn 24hrs. EDT
numberNumber (null for sperm whale encounters)
speciesSpecies observed
scientificScientific name
latLatitude of observation
longLongitude of observation
enctr_typeEncounter type
tsnSpecies ITIS TSN
geomGeometry field added by OBIS-SEAMAP
oidUnique ID number (generated by OBIS-SEAMAP)
Marine mammals85
Sea turtles0
Rays and sharks0
Other species0
Non spatial0
Non species0
Date, Begin2005-04-16
Date, End2005-06-23
Temporal prec.111111
Latitude16.58 - 43.94
Longitude-70.33 - -58.98
Coord. prec.6 decimal digits
Data typeAnimal sighting
EffortYES (ID: 333)
Traveled (km)9,538
Effort hours1,531
Sharing policy CC-BY-NC (Minimum)
Also availalbe from iOBIS
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