Satellite monitored dive characteristics of the northern right whale, Eubalaena glacialis
The western North Atlantic population of the northern right whale (Eubalaena glacialis) was severely depleted by whaling over the last century. Despite over fifty years of protection, fewer than four hundred individuals are believed to exist in the North Atlantic. Relatively little is known about th...
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| Other Authors: | , , , , |
| Format: | Master Thesis |
| Language: | English unknown |
| Published: |
Oregon State University
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| Online Access: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/hq37vs57f |
| Summary: | The western North Atlantic population of the northern right whale (Eubalaena glacialis) was severely depleted by whaling over the last century. Despite over fifty years of protection, fewer than four hundred individuals are believed to exist in the North Atlantic. Relatively little is known about the diving behavior, respiratory physiology, or diel activity of these whales, although such information could be useful in predicting population abundance and distribution in relation to food or environmental variables. Dive behavior data can be collected visually, but collection is limited to daylight hours, calm weather, and fortuitous encounters with study animals. Satellite-monitored radio tags offer the opportunity to collect data on individual whales' diving behavior continuously, over long distances and periods of time, and at relatively low cost. Thirteen North Atlantic right whales were tagged and monitored in the Gulf of Maine between 1989 and 1991. One male was tagged in 1989; two adult males, six adult females (two with calves) and one juvenile were tagged in 1990; one adult female (with a calf) and two juveniles were tagged in 1991. The duration of monitoring for the whales varied from <1 day to 43 days. Characteristics of the radio tags were different over each year in order to evaluate different attachment mechanisms and methods of collecting and summarizing data for dive duration, dive frequency, and time submerged. These data were then used to describe the dive behavior and to predict aspects of the respiratory physiology for these whales. The number of dives, their duration, and the time submerged varied considerably among individual whales and between years. Over all, the whales spent 79% of their time underwater. However, most dives were short (i.e., 95% were <14 min; the mean dive duration was 92.3 sec), although dives of 30-40 min duration were observed for several individuals. In general, the number of dives a right whale made was inversely related to the average duration of its dives ... |
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