Douglas et al. Seasonal distribution and abundance of cetaceans off Southern California 
209 
Table 5 
Density and abundance of cetaceans by species and season-and-depth stratum. The total area of the study area 
was 238,494 km 2 , with 71,407 km 2 in shallow depths (<2000.5 m) and 167,087 km 2 in deep depths (>2000.5 m). 
Coefficients of variation (CV) apply to both density and abundance estimates, and “NA” indicates that no CV was 
available because of a sample size equal to zero. Asterisks indicate mean values derived from the separate strati- 
fied densities for shallow and deep waters. See Table 2 for covariates used to estimate density by species group. 
Species 
Number of 
Mean group 
Density 
(individuals/ 
Uncorrected 
Season, depth 
groups 
size 
1000 km 2> 
abundance 
CV 
Blue whale 
Winter— spring, shallow 
0 
0.0 
0.00 
0 
NA 
Winter— spring, deep 
0 
0.0 
0.00 
0 
NA 
Summer— fall, shallow 
19 
1.4 
3.20 
228 
0.26 
Summer-fall, deep 
5 
1.2 
0.36 
59 
0.33 
Summer-fall, all depths 
24 
1.4 
1.21* 
288 
0.23 
Fin whale 
Winter-spring, shallow 
7 
2.0 
2.33 
166 
0.30 
Winter-spring, deep 
0 
0.0 
0.00 
0 
NA 
Summer-fall, shallow 
22 
1.4 
3.67 
262 
0.30 
Summer-fall, deep 
21 
2.0 
2.49 
417 
0.42 
Summer-fall, all depths 
43 
1.6 
2.84* 
679 
0.25 
Humpback whale 
Winter-spring, shallow 
8 
2 
2.66 
190 
0.33 
Winter-spring, deep 
3 
1.7 
0.34 
56 
0.58 
Winter-spring, all depths 
11 
1.9 
1.03* 
246 
0.29 
Summer-fall, shallow 
19 
1.4 
3.08 
220 
0.36 
Summer-fall, deep 
2 
4.5 
0.53 
89 
0.58 
Summer-fall, all depths 
21 
1.7 
1.29* 
309 
0.32 
Sperm whale 
Winter-spring, shallow 
1 
5 
0.83 
59 
0.70 
Winter-spring, deep 
5 
1.2 
0.40 
67 
0.40 
Summer— fall, shallow 
3 
2.7 
0.94 
67 
0.44 
Summer-fall, deep 
10 
1.6 
0.95 
158 
0.36 
Short-beaked common dolphin 
Winter-spring, shallow 
11 
57.6 
307.83 
21,981 
0.33 
Winter-spring, deep 
22 
127.8 
609.86 
101, 900 
0.45 
Winter-spring, all depths 
33 
104.3 
519.43* 
123,881 
0.21 
Summer-fall, shallow 
33 
104.8 
1319.69 
94,235 
0.24 
Summer-fall, deep 
51 
37.5 
454.35 
75,916 
0.20 
Summer-fall, all depths 
84 
63.9 
713.44* 
170,151 
0.14 
Long-beaked common dolphin 
Winter-spring, shallow 
1 
60 
30.90 
2207 
0.78 
Winter-spring, deep 
0 
0.0 
0.00 
0 
NA 
Summer-fall, shallow 
14 
217.2 
687.87 
49,118 
0.52 
Summer-fall, deep 
0 
0.0 
0.00 
0 
NA 
Pacific white-sided dolphin 
Winter-spring, shallow 
19 
13.2 
110.57 
7896 
0.38 
Winter-spring, deep 
14 
14 
41.91 
7002 
0.35 
Winter-spring, all depths 
33 
13.5 
62.46* 
14,898 
0.21 
Summer-fall, shallow 
11 
6.6 
29.24 
2088 
0.34 
Summer-fall, deep 
1 
3 
0.6967 
116 
0.72 
Summer-fall, all depths 
12 
6.3 
9.24* 
2204 
0.35 
Risso’s dolphin 
Winter-spring, shallow 
9 
19 
35.65 
2546 
0.36 
Winter-spring, deep 
0 
0.0 
0.00 
0 
NA 
Summer— fall, shallow 
3 
8.6 
3.90 
279 
0.55 
Summer-fall, deep 
0 
0.0 
0.00 
0 
NA 
table continued 
