Each of the 12 sampling locations had two sampling sites located
on a perpendicular path from shore and centred at 0.75 and 1.5 m
water depths (the water level rose 0.5 m throughout the month of
study). Within sites, we estimated the density of sockeye females and
sculpins, with the area surveyed dependent on the species. Sampling
sites for sockeye consisted of 5 × 5 m squares that were delineated at
the corners by large marked rocks. Sampling sites for sculpins consisted
of a 1-m2 area in the centre of the 5-m2 area, delineated by a
labelled rock (1–12) and a PVC quadrat carried by the surveyor. The
centres of the sampling sites (at a given depth) were spaced about
16.3 m apart, with a distance of about 11.3 m between the edges of
adjacent 5-m2 sampling sites. Perpendicular to the shoreline, the distance
between sampling sites within a location varied dependent on
the slope of the shoreline, from about 15 m in the inner and outer bay
where the slope was gentle to only a few metres in central spawning
area where the slope was steeper. Sockeye spawned at greater depths
than we were able to sample (to about 3.5 m), but our sampling area
included most of the area of spawning activity (Quinn and Foote
1994).