Quantitative sampling of sculpins was started on 2 August,
6 days before the first sockeye females established territories.
Even then, sculpins were more abundant on the portion of the
beach where sockeye spawning activity would eventually occur
compared with areas where spawning did not occur
(Fig. 1A). Sculpin abundance increased in these areas in the
days preceding 8 August, when sockeye females first established
nest sites, and continued to increase until about 4 days
after the density of breeding females peaked on 13 August.
Sculpin abundance declined slightly in the sampling areas
where little or no sockeye spawning activity was observed,
although there were slight increases at the beginning and end
of the sockeye spawning period. On the five sampling days
from 13 to 23 August, sculpin abundance in the 10 sampling
sites within the spawning area averaged 12.9/m2 compared
with 0.9/m2 in the 14 sampling sites in the nonspawning areas,
a 14.3-fold difference