496 
Fishery Bulletin 96(3), 1 998 
Year 
Figure 3 
Annual number of rockfishes impinged per million gallons of water 
pumped, for all species of rockfishes combined, 1977-93. Note log scale. 
See text for description of the calculation of mean. Error bars are ±1 SE. 
because rockfish of the three target spe- 
cies tend not to remain in King Harbor 
as adults. For this comparison, we used 
only the yearly catch rates from the Re- 
dondo Beach electrical power generating 
station that is closest to the King Har- 
bor transects. In the dive survey, all three 
species were common during the mid- to 
late-1970s (Fig. 5). However, by 1980, 
individuals of these species were rarely 
seen. Blue rockfish and bocaccio have not 
been observed since that time. Olive rock- 
fish have remained scarce, although 
small population increases were noted in 
the late 1980s and early 1990s. The pat- 
terns of impingement for these three spe- 
cies at Redondo show similar trends to that 
from the diver surveys. During the late 
1970s, olive rockfish were commonly im- 
pinged but catches declined markedly by 1980 (Fig. 5). 
Two of the slight increases noted in the diver survey 
in 1985 and 1991 were reflected in the impingement 
study, although the magnitude of the increase is 
greater in the SCE data in 1985 and in the diver 
surveys in 1991. In the impingement survey, blue 
rockfish catches were relatively high in the late 1970s 
and declined to zero in 1981 (Fig. 5). This pattern 
matches precisely the pattern observed in the diver 
surveys, with one exception. The exception was a one- 
day pulse of small blue rockfish caught in a single 
day at the Redondo station in 1982. Regarding blue 
rockfish, the two data sets are in general agreement; 
no blue rockfish have either been observed or cap- 
tured since 1983. Changes in abundance of bocaccio 
are also similar between the impingement data and 
the diver surveys (Fig. 5), with the exception of a 
large pulse of young bocaccio impinged during a 
single collection in 1988. 
Discussion 
From at least the 1950s through the late 1970s, black- 
and-yellow, blue, gopher, and olive rockfishes, as well 
as young bocaccio, were important components of the 
inshore rocky reef community of the SCB (Limbaugh, 
1955; Ebeling et al., 1980; Larson, 1980; Stephens et 
al., 1984, 1986; Patton et al., 1985). In particular, 
blue rockfish and olive rockfish were among the domi- 
nant species over many reefs (Carlisle et al., 1964, 
Ebeling et al., 1980). However, since the early 1980s, 
most species of rockfishes have nearly disappeared 
from the nearshore waters of the SCB (Stephens et 
al., 1994; Larson 5 ; Schroeder 6 ). On many of the reefs 
that once held substantial numbers of these species, 
very few rockfishes remain. Results of the fish-im- 
pingement surveys conducted since 1977 support the 
observation that several species of rockfish are less 
abundant now than in the late 70s and early 80s. We 
find it particularly compelling that for at least two 
species (blue rockfish and grass rockfish), not a single 
individual was collected in the past ten (blue rock- 
fish) or three (grass rockfish) years. 
We feel that the pattern of changing abundance in 
the impingement study is an accurate reflection of 
the pattern of change in the nearshore environment. 
Despite two very different survey methods, the pat- 
terns of rockfish abundance derived from the im- 
pingement data and the visual survey data from King 
Harbor were similar. On the gross level, the patterns 
for three species show amazing similarity; all have 
declined drastically since the late 70s and have re- 
mained low in the 80s and early 90s. On a finer scale, 
there were several large peaks in the impingement 
data that were not evident in the visual survey data 
(Fig. 5: blue rockfish in 1982, bocaccio in 1988). These 
differences may be due to differences in the ages of 
some of the fish recorded in the two surveys. Although 
the visual surveys mainly record juvenile blue rock- 
fish, olive rockfish, and bocaccio, they may occasion- 
ally include older individuals, whose population lev- 
els may be buffered from the potentially large varia- 
tions in recruitment by mortality. The impingement 
collections comprised mainly 0-2 year olds. Both of 
the large pulses seen in the impingement data were 
collections taken on a single day. 
5 Larson, R. 1997. Department of Biological Sciences, San 
Francisco State University, San Francisco, CA 94132. Personal 
commun. 
6 Schroeder, D. 1997. Marine Science Institute, University of 
California, Santa Barbara, CA 93106. Personal commun. 
