Bull Trout And Dams

Four bull trout redds were observed upstream from the fishways in Tributary 4 in 2016 including three redds upstream from the Ice Falls and a single redd located between the fishway and the beaver dams.

Bull trout and dams. Dams and poorly placed culverts can block migration routes of bull trout. We determined that spawn timing affected seasonal changes in dam passage for each species. Operating a fish trap at Milltown Dam in 2000 and 2001 I captured westslope cutthroat trout and bull trout implanted 42 with radio transmitters and transported them upstream of Milltown Dam.

Dams and other in-stream structures also effect bull trout by blocking migration routes altering water temperatures and causing loss of fish as they pass through and over dams or are trapped in irrigation and other diversion structures. Trout sea run cutthroat Oncorhyncus clarki clarki Dolly Varden trout Salvelinus malma malma and sockeye salmon are able to cross beaver dams101 In southeast Alaska coho jumped dams as high as two meters were found above all beaver dams and had their highest densities in streams with beaver104. Endangered Species Act 1998 and as vulnerable on the IUCN Red List of Threatened.

In the 2008 survey 3218 were counted. These obstructions remove spawning and nursery areas and disconnect part of the system. The bull trout Salvelinus confluentus is a char of the family Salmonidae native to northwestern North America.

During relicensing studies at Wells Dam bull trout moved upstream and downstream past Wells Dam freely with no observed mortality or passage delay. To date it has been assumed that adults from the NF Tieton population also reside in Rimrock Lake when not spawning or migrating. 04042016 The bull trout according to the Hydro documents will be taken by watercraft to the Halfway River about 30 kilometers upstream from the dam where they spawn in watershed creeks and rivers.

With their remaining habitat dwindling researchers seek to ensure new beaver dams dont inadvertently impede their migration. Connectivity is important for migrating fish such as bull trout. There are two additional Bull Trout populations found above Tieton Dam which spawn in separate tributaries of Rimrock Lake one in the South Fork Tieton River and the other in Indian Creek.

The two man-made dams as well as beaver dams are limiting the production of bull trout in the Clearwater. 11052020 Bull trout a threatened species swim upstream each fall to spawn in cold clean headwaters. Confluentus has been known as the Dolly Varden.