scholarly journals Summer and fall habitat of North Atlantic right whales (Eubalaena glacialis) inferred from satellite telemetry

2005 ◽  
Vol 62 (3) ◽  
pp. 527-543 ◽  
Author(s):  
Mark F Baumgartner ◽  
Bruce R Mate

Satellite-monitored radio tags were attached to North Atlantic right whales (Eubalaena glacialis) in Grand Manan Basin of the lower Bay of Fundy during the summer and early fall seasons of 1989–1991 and 2000. Monte Carlo tests were used to examine the distribution of the tagged whales in space and time and with respect to a variety of environmental variables to characterize right whale habitat on their northern feeding grounds. These environmental variables included depth, depth gradient, climatological surface and bottom hydrographic properties, and remotely sensed surface temperature, chlorophyll concentration, and their respective horizontal gradients. Site fidelity in the Bay of Fundy was very low during 1989–1991 and high during 2000. When the tagged animals left the Bay, they did not frequently visit the deep basins of the Gulf of Maine and Scotian Shelf, where abundances of their primary copepod prey, Calanus finmarchicus, are thought to be high. Instead, right whales visited areas characterized by low bottom water temperatures, high surface salinity, and high surface stratification. No evidence was found that the tagged right whales associated with oceanic fronts or regions with high standing stocks of phytoplankton.

1989 ◽  
Vol 67 (6) ◽  
pp. 1411-1420 ◽  
Author(s):  
L. D. Murison ◽  
D. E. Gaskin

Temperature, salinity, density of Zooplankton patches, and the abundance of right whales (Eubalaena glacialis glacialis) were measured concurrently during summer and autumn of 1983 and 1984 over the Grand Manan Basin, outer Bay of Fundy. Right whales appeared to exploit patches of copepods at densities greater than about 820/m3 (170 mg m−3). Patches were composed primarily of stage V Calanus finmarchicus at depths ≥ 100 m during daylight hours. Patch densities were similar in 1983 and 1984. Potential right whale feeding areas increased in extent from late July to October, with at least two peaks of copepod biomass occurring in 1984. Right whales appear to exploit euphausiid patches in the bay only incidentally; the whales departed in 1984 when euphausiid biomass was at a maximum. The topography of the basin, prevailing summer currents, and orientation of transition zones from mixed to stratified water all combine to facilitate accumulation of copepods from the Scotian Shelf and Gulf of Maine in the central lower Bay of Fundy. This area provides an important feeding ground for this stenophagous whale species.


1993 ◽  
Vol 71 (2) ◽  
pp. 339-345 ◽  
Author(s):  
Catherine M. Schaeff ◽  
Scott D. Kraus ◽  
Moira W. Brown ◽  
Bradley N. White

Photoidentifications and 11 years of sighting data revealed that only two-thirds of the western North Atlantic right whale (Eubalaena glacialis) reproductive females took their calves to the Bay of Fundy, the only known summer nursery. Study of cow–calf pairs further indicated that female, and to a lesser extent male, calves were philopatric with respect to this nursery. To further examine population structure, mtDNA composite restriction morphs were determined for 150 animals (47% of the population). Using 11 restriction enzymes, three composite mtDNA morphs were identified. One morph was not found among reproductive females that brought all of their calves to the Bay of Fundy. In contrast, all three morphs were present, in the same relative frequencies, among males that were seen in the Bay of Fundy and those that were not. These findings support the hypothesis that this population may be divided into two subgroups, which are defined by their use of the Fundy nursery, and that males are generally less philopatric than females. Animals from both subgroups were seen on the southern Scotian shelf, where most right whale courtship behavior was observed. Hence, although segregated by nursery areas, the western North Atlantic right whales probably represent a single breeding population.


2011 ◽  
Vol 68 (12) ◽  
pp. 2174-2193 ◽  
Author(s):  
Angelia S.M. Vanderlaan ◽  
R. Kent Smedbol ◽  
Christopher T. Taggart

Commercial fishing gear can potentially entangle any whale, and this is especially true for the endangered North Atlantic right whale ( Eubalaena glacialis ), for which entanglement is second only to vessel strike as being responsible for documented right whale deaths. We use right whale survey data and Canadian fishing-gear deployment data to estimate the relative threat of gear entanglement in a Scotia–Fundy study area and the relative risk of lethal entanglement in the Bay of Fundy and on Roseway Basin, Scotian Shelf, where Critical Habitat has been legislated. We focus on groundfish and pelagic hook-and-line; groundfish gillnet; and crab-, hagfish-, and inshore and offshore lobster-trap gear. Our analyses demonstrate that groundfish hook-and-line gear poses the greatest threat to right whales among the seven gear types analysed during the summer-resident period in Critical Habitat and that gear from the lobster fisheries poses the greatest threat during the spring and autumn periods when whales are migrating to and from Critical Habitat. We suggest that area-specific seasonal closures of some fisheries would reduce threat and risk to whales without unduly compromising fishing interests.


Sign in / Sign up

Export Citation Format

Share Document