Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4536348 | Deep Sea Research Part II: Topical Studies in Oceanography | 2014 | 7 Pages |
Abstract
The subarctic-subtropical transition area of the western North Pacific is an important summer feeding grounds of sei whales. The oceanographic structure and circulation of this area are largely determined by strong oceanic fronts and associated geostrophic currents, namely the Polar Front (PF), Subarctic Front (SAF) and Kuroshio Extension Front (KEF). The relationship between the distribution of sei whales and oceanographic fronts was investigated using a generalized additive model (GAM), and the cetacean sighting survey data and oceanographic observations in July from 2000 to 2007 were used in the analysis. The number of individual sei whales was used as the response variable while the distances from the PF, SAF, and KEF to the whales were used as explanatory variables along with the longitude values. Sei whales were concentrated north and south of the SAF and the areas from 250 to 300Â km north and from 100 to 200Â km south of the SAF were estimated as high-density areas of sei whales. The entire inter-frontal zone between the PF and SAF featured an elevated concentration of sei whales, and the area south of the PF and along the SAF was identified as an important feeding ground of sei whales in July from 2000 to 2007.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
Hiroto Murase, Takashi Hakamada, Koji Matsuoka, Shigetoshi Nishiwaki, Denzo Inagake, Makoto Okazaki, Naoki Tojo, Toshihide Kitakado,