Saving California’s native fishes: Physiological and behavioural approaches

Abstract

Many of California’s diverse, freshwater habitats have been modified, limiting the normal movements of many resident and migratory fishes. My students, colleagues and I used physiological and behavioural approaches to study the environmental requirements of native fishes that had low, or steeply declining, population sizes. Findings included swimming muscle ‘remodelling’ and decreases in sustained swimming performance in coho salmon as they developed towards their salt-water life-stage. These results, plus those on juvenile green sturgeon’s decreases in swimming performance with saltwater readiness and this species’ vulnerability to water diversions, should help natural resource managers set stream and river standards to ensure adequate flows for preserving our natural heritage of native fishes.