I have taken many pix of salmon spawning. For many of these shots it would not likely be possible for someone not rather knowledgeable about salmon or fish behavior to know what behavior was being shown without a caption. For example, I have many shots of females digging - either during preparation of the nest or redd as well as after spawning when the female covers the redd. These pix show a fish turned sideways. Eggs typically are hidden by milt and drop out of sight during spawning and so often I do not get any or just a few eggs in a pic.
In this shot a number of eggs are clearly seen. The female is turned just completeing a digging action following spawning, which has raised them into the water column, a bit atypical. The strobe light (from a Seacam Seaflash 250D) hit them just beyond the shadow cast by the male. I also like the play of light on the female's head. She has just tapped the surface, something they often do. Note the ripple. FYI, the egg in the foreground is probably from a different female. Eggs get displaced when females dig near a previously laid clutch. I suspect this is one. Camera: Canon EOS 1Ds MkII and 8-15mm zoom at 15mm. Seacam housing. Taken using remote control from about 10 meters away.