Offshore Migratory Corridors and Aerial Photogrammetric Body Length Comparisons of Southbound Gray Whales, Eschrichtius robustus, in the Southern California Bight, 1988–1990

Sumich, James L. and Show, Ivan T. (2011) Offshore Migratory Corridors and Aerial Photogrammetric Body Length Comparisons of Southbound Gray Whales, Eschrichtius robustus, in the Southern California Bight, 1988–1990. Marine Fisheries Review, 73(1), pp. 28-34.

[img]
Preview
PDF (The document's language is English .) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (1277Kb) | Preview
Official URL: http://spo.nmfs.noaa.gov/mfr731/mfr7313.pdf

Abstract

Through most of their annual migration, gray whales, Eschrichtius robustus, remain within 10 km of shore, but in the Southern California Bight many individuals migrate much farther from shore. This paper summarizes aerial survey and photogrammetric efforts to determine body lengths and temporal and spatial distributions of migratory gray whales in the southern portion of the Southern California Bight. Aerial surveys were flown along 13 east–west transects between lat. 32°35′N and 33°30′N during the southbound gray whale migratory seasons of 1988–90 in the Southern California Bight. Photogrammetry was used to obtain body length estimates of animals during some of the surveys. A total of 1,878 whales in 675 groups were sighted along 25,440 km of transect distance flown and 217 body lengths were measured. Using position and heading data, three major migratory pathways or corridors in the southern portion of the bight are defined. Those migrating offshore were split almost evenly between two corridors along the west sides of Santa Catalina and San Clemente Islands. These corridors converge on the mainland coast between San Diego and the United States–Mexico border. No whales larger than 11.5 m were photographed within 30 km of the mainland coast, suggesting that smaller, and presumably younger, whales use the coastal migratory corridor through the California Bight.

Item Type: Article
Title: Offshore Migratory Corridors and Aerial Photogrammetric Body Length Comparisons of Southbound Gray Whales, Eschrichtius robustus, in the Southern California Bight, 1988–1990
Personal Creator/Author:
CreatorsEmail
Sumich, James L.
Show, Ivan T.
Refereed: Yes
Journal or Publication Title: Marine Fisheries Review
Volume: 73
Number: 1
Page Range: pp. 28-34
Date: 2011
ISSN: 0090-1830
Issuing Agency: United States National Marine Fisheries Service
Subjects: Conservation
Fisheries
Management
Item ID: 9667
Depositing User: Patti M. Marraro
Date Deposited: 14 Aug 2012 16:31
Last Modified: 14 Aug 2012 16:31
URI: http://aquaticcommons.org/id/eprint/9667

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...