342 



Fishery Bulletin 88(2), 1990 



Figure 3 



Phocoena sinv.'i sighting rate (individuals/100 km) relative to sea state. 



=■ 1(1 



Group size 



(number of iiuiivitluals) 



N = 51 



Figure 4 



Phocoena sinus group size. 



that was not yet fully erect, and the ungainly manner 

 in which it ]ifte(i its hea(^ from the water with each 

 surfacing. 



Aerial surveys 



Eleven Phocoena sinus (five sightings) were seen dur- 

 ing aircraft surveys. All aerial sightings took place 

 between San Felipe and Rocas Consag, and none oc- 

 curred farther south along the Baja peninsula coast 

 (Fig. 2b), although much less effort was dedicated to 

 this area in relation to the extreme upper Gulf. The 



number of aircraft surveys was relatively small and 

 non-random. Nonetheless, they served to support P. 

 sinus distribution patterns observed during vessel sur- 

 veys, failed to yield sightings south of the area sur- 

 veyed by vessel, and illustrated the utility of aircraft 

 as a platform of observation in future study and cen- 

 sus of the species. 



Sympatric vertebrates 



Other marine vertebrates were seen near P. siyms; 



