Fort Rock Basin Redband

Oncorhynchus mykiss newberrii

Native Trout Fly Fishing

A Fort Rock basin redband from a small Oregon stream

Introduction

The Fort Rock basin redband trout and native to three streams in the Fort Rock Basin of central Oregon. The Fort Rock basin once drained to the Columbia River via the Crooked River, yet its redbands are most closely related to those of the Klamath basin to the south (Behnke 2002).

Life History Information

Like other internal basins in Oregon, the Fort Rock basin was once filled with a large Pleistocene lake, but today all that remains today is Silver Lake and Paulina Marsh. Historically Paulina Marsh had the ability to support adfluvial redbands, but this life history type was eliminated when the marsh was drained (ODFW 2005). Today the only suitable habitat for trout is the basin's three streams and as such these redbands exhibit a stream resident life history. These fish feed primarily on aquatic and terrestrial insects and attain a maximum size of around 12" at around three to five years old.

Status

Although a 1999 petition to list the redbands of the northern Great Basin including those from the Fort Rock basin was denied, the Oregon Department of Fish and Wildlife considers them to be at risk of extinction. The threats to these fish today are similar to those affecting other Oregon redband populations, with habitat destruction and the introduction of non-native fish being the two major problems. Of the three streams in the basin, Silver Creek has been the most affected by introductions of nonnative fish. Both hatchery rainbow trout and brook trout were extensively stocked in the creek and have replaced the redbands throughout most of the drainage (ODFW 2005). According to Behnke (1992) fish that he sampled in the basin showed a slight hybrid influence with hatchery rainbow trout.

Habitat destruction and general abuse of the watershed has also led to declines of these redbands. Paulina Marsh once provided an important rearing habitat for adfluvial redbands but was drained for agricultural proposes, leading to the elimination of this migratory life history. Grazing has also degraded the quality of the habitat, as was evident on the trips that I have taken to the basin. At the spot that I fished there was nothing done to keep the cattle away from the creek and cow pies were present right up to the edge of the stream. Beyond this there was evidence of cattle caused erosion, headcuts and destruction of riparian vegetation. Apparently some of the locals enjoyed utilizing the roadside sections of the streams as dumping grounds too with freshly dumped garbage present on both of my visits. Logging has also been an issue in the basin and has led to sedimentation in the vital headwater spawning habitat (ODFW 2005).

Description

The coloration of these fish is olive or bronze on the back and transitions to a yellowish color across the body. These redbands have a pink to brick red stripe along their lateral line, and their gill plates are a rosy or brick red color. The spotting pattern consists of small irregular shaped spots that are distributed above and below the lateral line and on the caudal and dorsal fins. Purplish colored elliptical shaped parr marks are often retained into maturity. The fins are orange, with the caudal fin being forked. The dorsal fin may be tipped with either orange or white and the lower fins are tipped with white.

Stream Resident Form

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Native Range

Native Trout Fly Fishing

A map of the native range of the Fort Rock basin redband trout. Data Sources: Behnke (2002) and ODFW (2005).