Document of dataset 3360

Dataset record

Type
Dataset
title in English
NMML Harbor Porpoise Vessel, SE Alaska, Spring 1993
Description in English
Abstract In spring 1993, the Alaskan panhandle and Prince William Sound were surveyed for harbor porpoise (Phocoena phocoena) from the NOAA John N. Cobb using line-transect methodology. The shipboard platform was 28.36 m (93 ft) in length with a bridge height of 4.27 m (14 ft). To obtain data on seasonal movements of porpoise, a limited number of transects were made in areas of known porpoise concentrations. When a sighting was made, the following variables were recorded: time, angle, number of reticles to the sighting, radar distance (nm) to the shoreline at the same angle of the sighting, the species, the count of the porpoise seen (best, high, and low), and the animal(s) direction of travel. Search effort was recoded by noting the time and location of the ship at the beginning and end of each transect. Purpose Although harbor porpoises, Phocoena phocoena, are known to occur throughout Alaska waters, few estimates of abundance exist. In 1991, the National Marine Mammal Laboratory initiated a 3 year study on Alaska harbor porpoises. The objectives of this program were to: 1) Obtain minimum population estimates in coastal waters using line transect methodology with a coefficient of variation for density estimates of less than 30% for each survey area, and 2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. The ability of the observers to sight porpoise was sensitive to environmental conditions. As expected, when conditions deteriorated the number of porpoises observed declined.
Abstract in English
Data from the Alaskan panhandle and Prince William Sound surveyed to study the Alaska harbor porpoise (Phocoena phocoena) in spring 1993.
License
https://spdx.org/licenses/CC-BY-NC-4.0.html
bibliographicCitation
Dahlheim, M. E., P. A. White, J. M. Waite. 2009. Cetaceans of Southeast Alaska: distribution and seasonal occurrence. Journal of Biogeography. 36: 410-426
Version
1

Temporal coverage

Temporal
Start date
1993-04-30
End date
1993-05-13

Geographical coverage

Spatial
I, North Pacific

Themes

theme
Biology > Mammals

Taxonomic terms

Taxon keywords
Cetacea

Ownerships

contributor
National Marine Mammal Laboratory
contactPoint
Kimberly Goetz
contactPoint
Duke University
contactPoint
Janice Waite
contactPoint
National Marine Mammal Laboratory

Publication references

related reference
Based on this dataset /id/publication/248356

Dataset references

record
Spatial Ecological Analysis of Megavertebrate Populations

Document metadata

date created
2012-11-14
date modified
2012-11-14