Native Trout Program - Redband Trout (Oncorhynchus mykiss)
Redband
trout are described as inland populations of Oncorhynchus mykiss, with
few morphological and meristic characters distinguishing them from coastal
rainbow trout (Behnke 1992). Redband trout range east of the Cascade
Mountain range from northern California and Nevada to northern British
Columbia and west central Alberta. In central and eastern Oregon, redband
trout are native to several isolated desert basins including the Malheur
Lakes basin.
The terminus of the Malheur Lakes basin is comprised of Malheur and
Harney lakes in the Malheur National Wildlife Refuge (Malheur NWR).
The Donner und Blitzen River flows to Malheur Lake from the Steen Mountains
to the south and contains the single truly migratory population of redband
trout in the basin. The migratory life history of this population is
impeded in the lower reaches of the Donner und Blitzen River by irrigation
weirs, dams and poor water quality. The Malheur NWR has placed ladders
on dams to facilitate improved passage and recently conducted a project
on a 6 km reach of the Donner und Blitzen River to improve habitat conditions
for redband trout.
The Native Trout Program has collaborated with the Malheur NWR to assess
the success of the recent habitat restoration project. The project involved
the placement of instream structures to create more pool and riffle
habitat as well as root wads to stabilize banks and improve cover. Pre-
and post-assessment of the habitat restoration project provides a basis
for comparison. Preliminary information and observations indicate that
the instream structures may be beneficial not only for redband trout,
but for other native species such as the bridgelip sucker, largescale
sucker, mountain whitefish, longnose dace, redside shiner and tui chub.
