Catlow Valley Redband

Oncorhynchus mykiss newberrii

Native Trout Fly Fishing

A Catlow Valley redband from an eastern Oregon desert stream

Introduction

The Catlow Valley redband trout are native to the streams of the Catlow Basin in southeastern Oregon. These fish are thought to be most closely related to Harney-Malheur Basin and Columbia Basin redband and are considered to be a part of the subspecies Oncorhynchus mykiss newberrii.

Life History Information

During the cooler climate period of the Pleistocene the Catlow Valley was filled with a large lake and under these conditions the fish adapted to a lacustrine life history. However as the climate warmed the basin's lake desiccated and the fish were isolated in streams on both the east and west sides of the valley. In recent times, these redbands had the ability to express migratory and even lacustrine life history types in the Catlow Marsh (Garrison Lake). However this life history type was lost when the Catlow Marsh was drained for agricultural proposes and only occurs during wet years in the reservoirs on Rock, Skull and Threemile Creeks (ODFW 2005). When it is available, this lacustrine life history type provides an important contribution to the continued survival of these populations as the reservoir dwelling females can contribute up to five times as many eggs as their stream dwelling counter parts (Kunkel 1976). However on Rock Creek, even when the reservoir is available as habitat, it is uncertain whether the redbands even have the ability to return upstream to suitable spawning habitat (Bowers et. al 1999). As such today the only suitable habitat for trout in the Catlow Valley is generally restricted to the upper reaches four small streams in the basin, and as a result these fish exhibit stream resident life history styles. The habitat in these streams is extremely unstable with rapid fluctuations in temperature. Under these conditions Catlow Valley redband trout have gained a genetic tolerance for high temperatures and have been shown to be able to withstand higher water temperatures than any other type of trout (Behnke 2002). Even with this adaptation though, the most suitable trout habitat in the valley is restricted to stream stretches with the presence of springs or occurring in canyons, and habitat provides important refuges during the warm conditions found in summer (ODFW 2005).

Status

In 1997 there was a petition to list the redbands of the desert basins of Oregon including the Catlow Valley redband under the Endangered Species Act (ESA) (USFWS 1997). This petition was denied, but has resulted in increased protection and monitoring for the redbands. In a 2005 status review of their state's endemic fish, the Oregon Department of Fish and Wildlife labeled the Catlow Valley redbands as being at risk of extinction (ODFW 2005). During this study the state identified five distinct populations of redbands, which included one that was said to be extinct in Guano Creek. According to Behnke (2008) though, Guano Creek is at a higher altitude and isolated from other streams in the Catlow Valley so it likely did not contain any native trout. Of the other streams mentioned, three were found to be depressed in one way or another and actions to restore degraded habitat along these creeks are being undertaken. The major causes of the decline these fish in the native streams has been from habitat alterations. This includes the loss of riparian vegetation and erosion due overgrazing, and dewatering of habitat for agricultural purposes.

Description

The coloration of these fish is olive or bronze on the back and transitions to brassy-yellow across the body. These redbands have a pink to brick red stripe along their lateral line, and the same coloration on their gill plates. The spotting pattern consists of small to medium round or irregular shaped spots that are profusely distributed above and slightly below the lateral line, and on the caudal and dorsal fins. The caudal fin is forked, dorsal fin may be tipped with either white or orange, and anal and pelvic fins are tipped with white. Parr marks are purplish in coloration and are generally retained into maturity.

Stream Resident Form

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Native Trout Fly Fishing
Native Trout Fly Fishing

 

Native Range

Native Trout Fly Fishing

A map of the native range of the Catlow Valley redband trout. Data Sources: Behnke (2002) and ODFW (2005).