| Abstract: | We estimated the critical swimming speeds (Ucrit) of wild bull trout at 6??, 11??, and 15??C in laboratory experiments. At 11??C, 5 fish ranging from 11 to 19 cm in length had a mean Ucrit of 48.24 cm/s or 3.22 body lengths per second (BL/s). Also at 11??C , 6 fish from 32 to 42 cm had a mean Ucrit of 73.99 cm/s or 2.05 BL/s. At 15??C, 5 fish from 14 to 23 cm had a mean Ucrit of 54.66 cm/s or 2.88 BL/s. No fish successfully swam at 6??C. Swim speed was significantly influenced by fish length. Many bull trout performed poorly in our enclosed respirometers: of 71 Ucrit tests we attempted, only the 16 described above were successful. Bull trout that refused to swim held station within tunnels by using their pectoral fins as depressors, or they rested and later became impinged against a downstream screen. Several common techniques did not stimulate consistent swimming activity in these fish. Our estimates of U crit for bull trout provide an understanding of their performance capacity and will be useful in modeling efforts aimed at improving fish passage structures. We recommend that fishway or culvert designers concerned with bull trout passage maintain velocities within their structures at or below our estimates of Ucrit, thus taking a conservative approach to ensuring that these fish can ascend migratory obstacles safely. |
| Genre: | Article |
| ProdID: | 70026191 |
| Citation Author: | Mesa, M. G.; Weiland, L. K.; Zydlewski, G. B. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 65 |
| Citation Issue: | 1 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Northwest Science |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 7 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Critical Swimming Speeds of Wild Bull Trout; 2004; Article; Journal; Northwest Science; Mesa, M. G.; Weiland, L. K.; Zydlewski, G. B. |
| Citation Start Page: | 59 |
| Citation Volume: | 78 |
| Citation Year: | 2004 |
| Type: | citation/reference |
| Text: | Critical Swimming Speeds of Wild Bull Trout; 2004; Article; Journal; Northwest Science; Mesa, M. G.; Weiland, L. K.; Zydlewski, G. B. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 2004 00:00 -0600 |
| Publisher: | |
