148 



speeds while feeding are usually around 1 knot (1.9 km/hr). 



P 3-19/1 1/L 7-8: Copepod patches in the Great South Channel are not usually 

 near the surface, except in a couple of years when they did not vertically 

 migrate on a 24-hour cycle (Wishner et a/., 1988, in prep.). Most right whale 

 feeding in the Great South Channel is not seen, and is presumed to occur at 

 depth (Kraus and Kenney, 1991; Kenney, Winn, and Macaulay, in prep.). 



P 3-19/1 3/L 7-9: This seems to be a misinterpretation of the data. Mate er a/. 

 (1992) showed mean percent submergence of 78%, and a mean dive time of 

 86 sec. However, most dives are short and shallow ones between blows 

 during a surfacing bout, following by a longer, deeper (presumed feeding or 

 traveling) dive. Mate's data showed dives up to 14.1 minutes, and CETAP 

 data showed dives to 15.8 min. Many feeding dives last longer than 3 

 minutes, and typically are in the 10-12 min range. Data from our radio-tag- 

 ging study in the Great South Channel in 1988 and 1989 (Winn et a/., in 

 prep.) showed that dives within surfacing bouts were typically less than 27 

 sec, while inter-bout dives averaged 2 min 7 sec and ranged to a maximum of 

 22 min 43 sec. 



P 3-21/1 2/L 4-8: The comparison between Sherman's and Mayo's data is not 

 valid. The former are based on MARMAP samples collected by paired bongos 

 and integrated over the entire water column. The latter are from discrete 

 samples collected over very short horizontal and vertical distances within 

 zooplankton patches. 



P 3-22/1 2/L 11-12: I don't believe that it has been established that nutrient avail- 

 ability is the primary immediate factor in the development of right whale prey 

 patches, in the Bays or elsewhere. It is just as possible that the patches 

 develop from zooplankton which are produced elsewhere, then advected into 

 and concentrated within a specific area by physical or a combination of physi- 

 cal and behavioral processes. Productivity is still an ultimate underlying fac- 

 tor, but the immediate factor is the concentration and patch development 

 process. 



P 3-22/1 2/L 12-15: Many of the literature sources which include krill as right 

 whale prey also specify juvenile krill. The swimming speed of a feeding right 

 whale is very similar to that of a fishing plankton net, and krill are very diffi- 

 cult to sample. Right whales probably have to swim much faster to catch 

 krill, with a much higher energetic cost. Hamner et al. (1988) observed 

 southern right whales swimming at speeds up to 8 knots (14.8 km/hr) while 

 feeding on Euphausia superba near Antarctica. The choice to leave an area of 

 obviously high krill abundance, possibly for another of high copepo'd abun- 



