The return of several animals back into the BOF after extensive travel revises former 

 assumptions regarding residency time. Previously, the time between repeat BOF sightings 

 within the same season was considered an estimate of minimum residency time. Now it is 

 obvious that animals can travel widely between such sightings. 



Feeding 



Because some animals stay in the BOF and others return after extensive travel, the 

 BOF appears to be an important area. We believe part of the importance of the BOF is 

 feeding because: 1) we observed very little breeding activity there; and, 2) we tagged 

 juveniles, females with calves and a pregnant female, none of which would normally have 

 been involved in mating activity. 



During our studies, we observed evidence of whales going to the bottom. Some 

 surfaced with mud on their heads in water 200 m deep suggesting bottom feeding. Data 

 from one whale instrumented for dive depths demonstrated dives to or near the bottom 

 routinely. Because copepods are weak diel migrators, prey depth and concentrations are not 

 predictable. Therefore, right whales may routinely examine several hundred meters of the 

 water column to locate their food which may often include the bottom. Their long dive 

 capability also allows them to forage at these reasonable depths. The concentration of 

 whales we observed in the BOF suggests that large tidal changes and associated currents 

 might concentrate diurnal migrants in the deeper channels. 



Recent studies on the Scotian Shelf by C. Miller (pers. comm.) show copepods 

 concentrated on the banks in the summer and moving into the basins during the fall. The 

 movements of two males in October and November into the basins east and southeast of 

 Nova Scotia suggest that these may be fall (if not winter) feeding areas. 



The concentration of "deep dives" along the 200 m contour east of Jeffreys Ledge 

 occurred in an area of frequent upwelling. Dives in this region were most consistently in the 

 range of 130 m and may thus have been "off the bottom." The significance of the 200 m 

 contour for right whales in our studies is similar to the 100 m contour found by Winn, et al. 

 (1986) and CeTAP (1982) in the Great South Channel. The bank edges used by right 

 whales in our studies adjoin basins which may harbor copepod concentrations, but also often 

 correspond to the continental slope edge dropping off into deep water. 



Many of the whale's movements coincided with eddies and thermal features such as 

 fronts, upwellings and warm core rings (WCR). Upwellings usually have higher productivity, 

 and fronts and eddies frequently concentrate prey. We were particularly surprised to see 

 movements along a warm core ring edge far offshore in deep water. We do not know if 

 right whales seek prey in areas of previous success, or recognize oceanographic 

 characteristics where prey would concentrate. 



137 



