| Title | Implications of metrics and methodology for juvenile salmonid monitoring in western Oregon streams |
| Publication Type | Journal Article |
| Year of Publication | 2023 |
| Authors | Constable, Jr., Ronald J., and Erik Suring |
| Secondary Title | Northwest Science |
| Volume | 96 |
| Number | 1-2 |
| Pagination | p.63-79 |
| Date Published | 2023 |
| Call Number | OSU Libraries: Electronic Subscription |
| Keywords | Coho salmon = Oncorhynchus kisutch, juvenile fish, population count, steelhead trout = Oncorhynchus mykiss, Umpqua River Basom, Upper Smith River |
| Notes | Since 1998, the Oregon Dept. of Fish and Wildlife has monitored populations of juvenile coho salmon in Oregon streams for population density and abundance. The Dept. has monitored juvenile steelhead trout since 2002. ODFW uses two methods to monitor fish populations: electrofishing and snorkeling. Neither method works in every setting: electrofishing doesn’t work in non-wadable streams and is too expensive to use everywhere, and some streams are too shallow for snorkeling. An early study had indicated that there would be many juvenile fish in areas where there were many parental fish. Sampling, however, revealed variations in juvenile fish abundance that were not explained by parental abundance. Was the problem with the operating assumption or with the methods of counting fish? Researchers learned that sampling for population density did not provide desired results, and that sampling for abundance was more accurate. Snorkeling turned out to be extremely accurate, and the standard for water depth for snorkeling could be lowered by 10 cm., making more streams available for this method. These changes will give ODFW better ability to monitor vulnerable salmonids. |
| DOI | 10.3955/046.096.0106 |
| Series Title | Northwest Science |
