Abstract

A GIS Model of Gray Whale Habitat-Use off Vancouver Island
Track: Ocean, Coastal, and Marine Resources
Author(s): David Laskin, Darren Bender, Dave Duffus

Marine GIS modeling and a modified form of binary logistic regression were used to assess habitat-use of gray whales (Eschrichtius robustus) along the south coast of Flores Island, British Columbia. Principle objectives include the derivation of a resource selection function (RSF) to determine relative likelihood of use of available bathymetric depth, slope and complexity features within the study area. Micro-scale pelagic currents were subsequently incorporated to examine their potential impact on habitat use. 877 whale presence observations were contrasted with bathymetric layers to produce a RSF identifying increased whale occurrence in waters ~10 meters deep, in combination with areas of higher benthic topographical complexity. Acoustic Doppler current profiling data were used to derive continuous current surfaces at three separate depths of the water column. The effects of current speed and direction on foraging whales were found to be negligible, but areas with south flowing surface currents consistently predicted increased use.

David Laskin
University of Calgary
Dept. of Geography,
2500 University Drive
Calgary , Alberta T2N 1N4
Canada
Phone: 403-210-8761
E-mail: dnlaskin@ucalgary.ca

Darren Bender
University of Calgary
Dept. of Geography
2500 University Drive
Calgary , Alberta T2N 1N4
Canada
Phone: 403-220-6398
E-mail: dbender@ucalgary.ca

Dave Duffus
University of Victoria
Dept. of Geography
PO Box 1700 STN CSC
Victoria , BC V8W 2Y2
Canada
Phone: 250-721-7344
E-mail: dduffus@mail.geog.uvic.ca