Douglas et al. Seasonal distribution and abundance of cetaceans off Southern California 
205 
Table 3 
Sighting data (number of encounters and estimated number of individuals) from 16 line-transect surveys conducted off 
Southern California from July 2004 to April 2008 on the 6 southern transect lines of quarterly California Cooperative 
Oceanic Fisheries Investigation (CalCOFI) cruises. Opportunistic effort is the category for sightings made off effort or 
when a vessel was not on a CalCOFI transect line. 
On effort 
Opportunistic effort 
Total 
Number of 
Number of 
Number of 
Number of 
Number of 
Number of 
Species 
encounters 
individuals 
enccounters 
individuals 
encounters 
individuals 
Humpback whale 
34 
60 
6 
13 
40 
73 
Blue whale 
25 
34 
20 
27 
45 
61 
Fin whale 
53 
100 
9 
10 
62 
110 
Minke whale 
10 
10 
8 
9 
18 
19 
Sei whale 
0 
0 
1 
1 
1 
1 
Bryde’s/sei whale 
1 
1 
1 
1 
2 
2 
Gray whale 
8 
16 
16 
33 
24 
49 
Sperm whale 
20 
36 
11 
18 
31 
54 
Baird’s beaked whale 
1 
20 
0 
0 
1 
20 
Cuvier’s beaked whale 
3 
3 
1 
3 
4 
6 
Killer whale 
2 
9 
0 
0 
2 
9 
Short-finned pilot whale 
1 
33 
1 
30 
2 
63 
False killer whale 
1 
10 
0 
0 
1 
10 
Short-beaked common dolphin 
122 
11,067 
96 
8677 
218 
19,744 
Long-beaked common dolphin 
Common dolphin 
17 
3259 
39 
7652 
56 
10,911 
(unknown Short- or long-beaked) 
72 
6532 
75 
12,443 
147 
18,975 
Pacific white-sided dolphin 
46 
573 
34 
467 
80 
1040 
Risso’s dolphin 
14 
205 
25 
505 
39 
710 
Bottlenose dolphin 
12 
220 
18 
221 
30 
441 
Northern right whale dolphin 
13 
480 
12 
245 
25 
725 
Rough-toothed dolphin 
0 
0 
1 
9 
1 
9 
Striped dolphin 
2 
77 
1 
7 
3 
84 
Harbor porpoise 
0 
0 
1 
2 
1 
2 
Dali’s porpoise 
49 
267 
24 
115 
73 
382 
Unidentified large cetacean 
123 
153 
74 
98 
197 
251 
Unidentified small cetacean 
63 
5496 
61 
3703 
124 
9199 
Unidentified Mesoplodon 
1 
1 
0 
0 
1 
1 
Total for cetaceans 
693 
28,662 
535 
34,289 
1228 
62,951 
California sea lion 
154 
1318 
85 
606 
239 
1924 
Northern fur seal 
59 
78 
14 
20 
73 
98 
Guadalupe fur seal 
0 
0 
2 
2 
2 
2 
Steller sea lion 
1 
1 
0 
0 
1 
1 
Northern elephant seal 
11 
11 
2 
2 
13 
13 
Harbor seal 
0 
0 
3 
3 
3 
3 
Sea otter 
0 
0 
1 
1 
1 
1 
Unidentified fur seal 
1 
1 
0 
0 
1 
1 
Unidentified pinniped 
12 
19 
4 
4 
16 
23 
Total for pinnipeds or mustelids 
238 
1428 
111 
638 
349 
2066 
Grand total 
Total transect line surveyed (km) 
931 
19,996 
30,090 
646 
5083 
34,927 
1577 
25,079 
65,017 
were recorded of Pacific white-sided dolphin with un- 
identified common dolphins, Risso’s dolphin with north- 
ern right whale dolphin, and Risso’s dolphin with bot- 
tlenose dolphin. 
Harbor porpoise ( Phocoena phocoena) were encoun- 
tered on a single survey north of Point Conception and 
were excluded from analyses because the study area in- 
cluded only the very southern tip of the regular habitat 
of this species off California (Barlow, 1988; Forney et 
al., 1991). Rough-toothed dolphins (Steno bredanensis) 
and false killer whales (Pseudorca crassidens ) were also 
encountered once each; both encounters were excluded 
