Sargasso 2005 - cetacean sightings

Hal Whitehead, Department of Biology, Dalhousie 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.

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.

Overview

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
cruise_leg	Cruise leg
day	Day of observation
month	Month of observation
year	Year of observation
hour	In 24hrs. EDT
minute	Minute
number	Number (null for sperm whale encounters)
species	Species observed
scientific	Scientific name
lat	Latitude of observation
long	Longitude of observation
enctr_type	Encounter type
tsn	Species ITIS TSN
geom	Geometry field added by OBIS-SEAMAP
oid	Unique ID number (generated by OBIS-SEAMAP)