Fish predation on salmon eggs has been noted in many
cases, but its effect on salmon production remains questionable.
Freshwater sculpins, family Cottidae, have long been suspected
as significant predators on salmonid eggs (e.g., Reed
1967; Savino and Henry 1991). However, Moyle (1977) concluded
that while sculpins clearly ate salmonid eggs, they
tended to eat eggs that were already exposed and at drift, and
hence were unlikely to have survived in any case.
Iliamna Lake, Alaska, is the single largest sockeye salmon
(Oncorhynchus nerka) producing lake in the world, with total
runs sometimes in excess of 30 million fish (Eggers and Rogers
1987). Sockeye salmon spawning on island beaches in
Iliamna Lake can sometimes account for near 30% of the total
escapement to the lake. These beach populations are notable
in that the females have a very short spawning duration (e.g.,
Hendry et al. 1995) and among the largest eggs observed in
the species (Quinn et al. 1995).