782 



Fishery Bulletin 92(4), 1994 



most continental shelf waters of the U.S. Gulf (Lo- 

 wery, 1974; Scott et al. 1 ; Rademacher 2 ) may be true, 

 we did sight Risso's dolphins, pygmy and dwarf sperm 

 whales, SSC dolphins, pantropical spotted dolphins, 

 and a sperm whale at depths less than 200 m. Fritts 

 et al. (1983) identified a sperm whale and SSC dol- 

 phins on the continental shelf off southern Florida. 

 In general, our results of mean herd size for most 

 species were similar to those reported from the At- 

 lantic and Pacific oceans (Yamada, 1954; Ross, 1978; 

 Leatherwood et al., 1980; Fritts et al., 1983; Leath- 

 erwood and Reeves, 1983; Vidal et al., 1987; Scott 

 and Cordaro, 1987; Kruse, 1989; Wade and Ger- 

 rodette, 1993; CeTAP 6 ). Our mean herd size for sperm 

 whales (2.1 animals) was slightly smaller than the 



mean of 3.5 animals reported by Collum and Fritts 

 (1985) from Gulf sightings. However, in other areas 

 of the world, mixed-sex herds and bachelor herds of 

 sperm whales range from 20 to 40 whales (Rice, 

 1989). 



The maximum herd sizes reported from the Atlan- 

 tic and Pacific oceans were much greater than those 

 observed in this study, where the largest herd was 

 estimated at 325 animals. Maximum herd sizes of 

 Risso's dolphins, bottlenose dolphins, striped dol- 



6 CeTAP. 1982. Acharacterization of marine mammals and turtles 

 in the mid- and north-Atlantic areas of the U.S. outer continen- 

 tal shelf. Final Report of the Cetacean and Turtle Assessment 

 Program, BLM Contract AA551-CT8-48, U.S. Dep. Interior, 

 Washington D.C., 450 p. 



