Fishes and their aquatic-riparian habitats along the Willamette River
Fish communities and their habitats in the mainstem Willamette River have been studied since the early 1900s (Snyder 1908; Dimick and Merryfield 1945; Hughes and Gammon 1987), but they have received considerable more attention since 2000 (Gregory et al. 2002; Hughes et al. 2005; McGarvey and Hughes 2008; Williams 2014; Gregory et al. 2019; Hughes et al. 2021). Intensive sampling of the Willamette River was started in 2011 by Dr. Stan Gregory of the Department of Fisheries, Wildlife, and Conservation Sciences at Oregon State University to understand fish community species composition, channel complexity, and floodplain forests and how they change over time.
In the initial survey, the foundational protocol and sampling techniques along a pre-defined spatial framework was established. Protocol and sampling are cataloged in the Oregon Explorer and through the Oregon State University ScholarsArchive@OSU. Fish are sampled with both backpack and boat electro-fishing and habitat characteristics are recorded for each fish sampling area. During the 2011 survey 41 fish species were collected, 22 of them were native species, and the other 19 were not (Williams 2014). Gregory and his team found higher numbers of fishes in the upper river relative to the lower river, and in terms of numbers, the majority were native species.
The intention is to continue the evaluation of the status of fish species composition, channel complexity, and floodplain forests every decade following the original sampling event. In 2020, Stan Gregory passed the fish decadal sampling on the Willamette River to Dr. Brooke Penaluna, Pacific Northwest Research Station, USDA Forest Service. Dr. Penaluna joined forces with Dr. Guillermo Giannico, Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, to complete the first decadal sampling event in 2021-2023.
Dr. Stan Gregory and Randy Wildman trained Dr. Penaluna and her crew in the protocol so there would be consistency across decades. In the 2021-2023 assessment, we aim to document current fish community composition and the relationships between native and non-native fishes and their habitats.
Literature Cited
Dimick, R.E. and Merryfield, F., 1945. The fishes of the Willamette River system in relation to pollution.
Gregory, S., Ashkenas, L., Oetter, D., Minear, P., & Wildman, K. 2002. Historical Willamette River channel change). In D. Hulse, S. Gregory, & J. Baker (Eds.), Willamette River Basin planning atlas: Trajectories of environmental and ecological change (pp. 18– 25). Corvallis, Oregon: Oregon State University Press.
Gregory, S., Wildman, R., Hulse, D., Ashkenas, L. and Boyer, K., 2019. Historical changes in hydrology, geomorphology, and floodplain vegetation of the Willamette River, Oregon. River Research and Applications, 35(8), pp.1279-1290.
Hughes, R.M. and Gammon, J.R., 1987. Longitudinal changes in fish assemblages and water quality in the Willamette River, Oregon. Transactions of the American fisheries Society, 116(2), pp.196-209.
Hughes, R.M., Wildman, R.C., Gregory, S.V. and Gammon, J.R., 2005. Changes in fish assemblage structure in the main-stem Willamette River, Oregon. In American Fisheries Society Symposium (Vol. 45, p. 61). American Fisheries Society.
Hughes, R.M., Herlihy, A.T. and Peck, D.V., 2021. Sampling efforts for estimating fish species richness in western USA river sites. Limnologica, 87, p.125859.
McGarvey, D.J. and Hughes, R.M., 2008. Longitudinal zonation of Pacific Northwest (USA) fish assemblages and the species-discharge relationship. Copeia, 2008(2), pp.311-321.
Snyder, J.O., 1908. The fishes of the coastal streams of Oregon and northern California (Vol. 638). US Government Printing Office.
Williams, J.E., 2014. Habitat relationships of native and non-native fishes of the Willamette River, Oregon. Master’s thesis. Oregon State University.