274 
Fishery Bulletin 96(2), 1 998 
Table 2 
Observed (obs) and (est) estimated cetacean, pinniped, turtle, and seabird mortality, stratified by year, in the California sword- 
fish and shark drift gillnet fishery during the NMFS Observer Program, July 1990-December 1995. Estimates of total mortality 
are reported to the nearest individual. Estimated coefficients of variation (CV) are included in parentheses; ( — ) indicates CV was 
undefined. Effort and estimates for 1990 pertain to the third and fourth quarters only. 
Year 
1990 
1991 
1992 
1993 
1994 
1995 
Estimated days effort 
4,078 
4,778 
4,379 
5,442 
4,248 
3,673 
Observed days effort 
178 
470 
596 
728 
759 
572 
Percent observer coverage 
4.4% 
9.8% 
13.6% 
13.4% 
17.9% 
15.6% 
Observed trips effort 
54 
88 
97 
107 
134 
97 
obs 
est 
CV 
obs 
est 
CV 
obs 
est 
CV 
obs 
est 
CV 
obs 
est 
CV 
obs 
est 
CV 
Dali’s porpoise 
1 
23 
(0.95) 
2 
20 
(0.67) 
1 
7 
(0.92) 
9 
67 
(0.44) 
2 
11 
(0.64) 
1 
6 
(0.92) 
Pacific white-sided dolphin 
3 
69 
(0.56) 
5 
51 
(0.63) 
3 
22 
(0.70) 
2 
15 
(0.66) 
3 
17 
(0.67) 
1 
6 
(0.92) 
Risso’s dolphin 
0 
0 
(— ) 
5 
51 
(0.50) 
5 
37 
(0.48) 
7 
52 
(0.51) 
1 
6 
(0.91) 
6 
39 
(0.57) 
Bottlenose dolphin 
0 
0 
(— ) 
0 
0 
(— ) 
3 
22 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Striped dolphin 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.90) 
0 
0 
(— ) 
Common dolphin 
(unknown stock) 
4 
92 
(0.79) 
7 
71 
(0.70) 
5 
37 
(0.40) 
4 
30 
(0.57) 
1 
6 
(0.91) 
0 
0 
(— ) 
Common dolphin (long beak) 
0 
0 
(— ) 
0 
0 
(— ) 
2 
15 
(0.92) 
0 
0 
(— ) 
1 
6 
(0.91) 
6 
39 
(0.65) 
Common dolphin (short beak) 
4 
92 
(0.47) 
37 
376 
(0.21) 
39 
287 
(0.21) 
24 
179 
(0.26) 
25 
140 
(0.18) 
36 
231 
(0.29) 
Northern right whale dolphin 
0 
0 
(— ) 
7 
71 
(0.41) 
2 
15 
(0.65) 
7 
52 
(0.39) 
7 
39 
(0.42) 
9 
58 
(0.59) 
Killer whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.92) 
Short-finned pilot whale 
1 
23 
(0.95) 
0 
0 
(— ) 
1 
7 
(0.92) 
8 
60 
(0.54) 
0 
0 
(— ) 
0 
0 
(— ) 
Baird’s beaked whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.90) 
0 
0 
(— ) 
Stejneger’s beaked whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.91) 
0 
0 
(— ) 
Hubbs’ beaked whale 
0 
0 
(— ) 
0 
0 
(— ) 
3 
22 
(0.53) 
0 
0 
(— ) 
2 
11 
(0.64) 
0 
0 
(— ) 
Mesoplodont beaked whale 
1 
23 
(0.97) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Cuvier’s beaked whale 
0 
0 
(— ) 
0 
0 
(— ) 
6 
44 
(0.36) 
3 
22 
(0.53) 
6 
34 
(0.36) 
5 
32 
(0.40) 
Unidentified beaked whale 
0 
0 
(— ) 
0 
0 
(— ) 
2 
15 
(0.65) 
0 
0 
(— ) 
1 
6 
(0.90) 
0 
0 
(— ) 
Sperm whale 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.94) 
2 
15 
(0.66) 
0 
0 
(— ) 
0 
0 
(— ) 
Pygmy sperm whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
Unidentified Kogia 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.92) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Minke whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.91) 
0 
0 
(— ) 
Unidentified cetacean 
0 
0 
(— ) 
1 
10 
(0.95) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Unidentified dolphin 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Unidentified whale 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
Steller sea lion 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.92) 
0 
0 
(— ) 
1 
6 
(0.91) 
0 
0 
(— ) 
California sea lion 
2 
46 
(0.99) 
4 
41 
(0.58) 
9 
66 
(0.34) 
11 
82 
(0.42) 
5 
28 
(0.40) 
4 
26 
(0.45) 
Unidentified sea lion 
2 
46 
(0.97) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Harbor seal 
1 
23 
(0.95) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Northern elephant seal 
5 
115 
(0.44) 13 
132 
(0.25) 
15 
110 
(0.24) 14 
105 
(0.26) 22 
123 
(0.23) 
14 
90 
(0.25) 
Loggerhead turtle 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
Leatherback turtle 
1 
23 
(0.97) 
0 
0 
(— ) 
2 
15 
(0.65) 
2 
15 
(0.66) 
0 
0 
(— ) 
4 
26 
(0.55) 
Unidentified turtle 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
7 
(0.93) 
0 
0 
(— ) 
0 
0 
(— ) 
Seabirds (all unidentified) 
1 
23 
(0.98) 
0 
0 
(— ) 
0 
0 
(— ) 
0 
0 
(— ) 
1 
6 
(0.90) 
0 
0 
(— ) 
errors, those not due to the sampling design, include 
but are not limited to 
made. The occurrence of this type of error implies 
that estimates of mortality are biased lower than 
actual mortality levels. 
1 Effort that is not recorded. This type of error may 
occur for several reasons, namely the times when 
no marketable target fish are caught during the 
entire day of effort and when a log entry is not 
2 Incorrect reporting of effort location by fishermen. 
This type of error may bias estimated mortality 
either higher or lower. 
