D.B. Hayes | USGS Science

USGS2006

Predation on walleye eggs by fish on reefs in western Lake Erie

We examined diets of fishes from gillnet and egg pump collections conducted on reefs in western Lake Erie during walleye ( Sander vitreus ) egg incubation periods from 1994–1999 and 2004 to assess incidence of walleye eggs in fish diets. We collected no potential egg predators in samples taken in 1994 but from 1995–1999 and in 2004 we caught 22 different species of fish on reefs in addition to spawning walleye. In most years, white perch ( Morone americana ) stomachs contained more walleye eggs than any other species on the reefs averaging 253 eggs per stomach. We also found lower numbers of walleye eggs in the stomachs of channel catfish ( Ictalurus punctatus ; 53 eggs/stomach), johnny darter ( Etheostoma nigrum ; 2 eggs/stomach), logperch ( Percina caprodes ; 10 eggs/stomach), quillback ( Carpiodes cyprinus ; 184 eggs/stomach), rock bass ( Ambloplites rupestris ; 3 eggs/stomach), round goby ( Neogobius melanostomus ; 4 eggs/stomach), sculpin ( Cottidae ; 21 eggs/stomach), silver chub ( Macrhybopsis storeriana ; 3 eggs/stomach), spottail shiner ( Notropis hudsonius ; 14 eggs/stomach), trout-perch ( Percopsis omiscomaycus ; 30 eggs/stomach), white sucker ( Catastomus commersonii ; 20 eggs/stomach), and yellow perch ( Perca flavescens ; 181 eggs/stomach). Similar to other studies of predation on walleye eggs, our results indicate that prolonged incubation periods increase the potential for egg loss due to predation.

Journal of Great Lakes Research↗

USGS2003

Low-head sea lamprey barrier effects on stream habitat and fish communities in the Great Lakes basin

Low-head barriers are used to block adult sea lamprey (Petromyzon marinus) from upstream spawning habitat. However, these barriers may impact stream fish communities through restriction of fish movement and habitat alteration. During the summer of 1996, the fish community and habitat conditions in twenty-four stream pairs were sampled across the Great Lakes basin. Seven of these stream pairs were re-sampled in 1997. Each pair consisted of a barrier stream with a low-head barrier and a reference stream without a low-head barrier. On average, barrier streams were significantly deeper (df = 179, P = 0.0018) and wider (df = 179, P = 0.0236) than reference streams, but temperature and substrate were similar (df = 183, P = 0.9027; df = 179, P = 0.999). Barrier streams contained approximately four more fish species on average than reference streams. However, streams with low-head barriers showed a greater upstream decline in species richness compared to reference streams with a net loss of 2.4 species. Barrier streams also showed a peak in richness directly downstream of the barriers, indicating that these barriers block fish movement upstream. Using S??renson's similarity index (based on presence/absence), a comparison of fish community assemblages above and below low-head barriers was not significantly different than upstream and downstream sites on reference streams (n = 96, P > 0.05), implying they have relatively little effect on overall fish assemblage composition. Differences in the frequency of occurrence and abundance between barrier and reference streams was apparent for some species, suggesting their sensitivity to barriers.

Conference Paper↗