Original provider:
Dalhousie University
Dataset credits:
Hal Whitehead, Department of Biology, Dalhousie University
Abstract:
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.
Purpose:
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.
English Version