162 
Fishery Bulletin 112(2-3) 
Transect lines surveyed for all studies of small cetaceans off Southern California in 
1979-2009. Orange lines indicate surveys conducted during California Cooperative 
Oceanic Fisheries Investigations (CC) cruises from 1987 to 2004, green lines indicate 
CC surveys conducted from 2004 to 2009, and purple lines indicate surveys conducted 
by the NOAA Southwest Fisheries Science Center (SWFSC) from 1979 to 2009. Black 
lines indicate latitude and longitude in 1° increments, which were used to create the 
grid sections for analyses in the generalized additive models. 
this analysis. The 3 warm-temperate and tropical spe- 
cies were short-beaked common dolphin ( Delphinus 
delphis), long-beaked common dolphin ( D . capensis), 
and striped dolphin ( Stenella coeruleoalba). The 3 cold- 
temperate species were Pacific white-sided dolphin 
( Lagenorhynchus obliquidens), northern right whale 
dolphin (Lissodelphis borealis), and Dali’s porpoise 
( Phocoenoides dalli). The remaining 2 species were 
considered cosmopolitan, distributed globally in tropi- 
cal and temperate waters: Risso’s dolphin (Grampus 
griseus) and bottlenose dolphin (Tursiops truncatus ) 
(Reeves et ah, 2002). 
All bottlenose dolphin sightings in this study were 
presumed to be offshore animals because most coast- 
al animals remain within about 1 km from the shore 
(Hanson and Defran, 1993) and surveys were conduct- 
ed at least 5-10 km from the coast. In addition to their 
individual species’ models, short- and long-beaked com- 
mon dolphins were combined into an additional Del- 
phinus species category because the 2 species were not 
recognized formally as distinct until 1994 (Heyning 
and Perrin, 1994). Furthermore, they were not distin- 
guished on SWFSC cruises before 1991 or on CalCOFI 
cruises before August 2004. Therefore, the data sets 
for long-beaked and short-beaked common dolphin are 
smaller than the data sets for all other species, and 
the data set for Delphinus spp. consists of all combined 
common dolphin sightings from all cruises. 
4 quarters (winter, spring, summer, and fall; see the 
next section. Environmental data, for details). A full 
summary of surveys, along with total effort (in kilome- 
ters) and sightings per year for all species is provided 
in Appendix I. 
Data for analyses also came from 10 different SWF- 
SC cruises, conducted primarily in the summer and fall 
(from July through November) from 1979 through 2005 
and covering an area that included Southern Califor- 
nia waters (Appendix I). For SWFSC cruises, standard 
line-transect protocols were followed, as described in 
Barlow and Forney (2007) and Kinzey et al. 2 The latter 
cruises had 3 observers on the flying bridge, 2 of whom 
used “big eye” 25x150 binoculars to scan 90° from bow 
to abeam on either side of the flying bridge. The third 
observer monitored the entire forward 180° with 7x50 
binoculars and the naked eye. Survey effort (in kilome- 
ters) was calculated either from the latitude and lon- 
gitude positions at the start and end of each trackline 
(1979-84 surveys) or from latitude and longitude posi- 
tions recorded approximately every 10 min along the 
track (1991-2005 surveys). 
Eight species of small cetaceans were examined in 
2 Kinzey, D., P. Olson, and T. Gerrodette. 2000. Marine mam- 
mal data collection procedures on research ship line-transect 
surveys by the Southwest Fisheries Science Center. NOAA 
Southwest Fisheries Science Center, Admin. Rep. LJ-00-08, 
32 p. 
