We evaluated the impact of land cover on fish assemblages by examining relationships between stream hydrology, physicochemistry, and instream habitat and their association with fish responses in streams draining 18 watersheds of the Lower Piedmont of western Georgia. Several important relationships between land use and physicochemical, hydrological, and habitat parameters were observed, particu...

—Identifying the overall status of freshwater streams is an important step in evaluating effects of land management and prioritizing restoration activities. To address these needs, we developed an index of physical habitat condition for headwater streams based on physical stream habitat data (2003–2007) and evaluated the condition status of 217 reference streams and 934 managed streams in the i...

—We quantified the relationships among urban land cover, fishes, and habitat quality to determine how fish assemblages respond to urbanization and if a habitat index can be used as an indirect measure of urban effects on stream ecosystems. We sampled 30 wadeable streams along an urban gradient (5–37% urban land cover) in the Etowah River basin, Georgia. Fish assemblages, sampled by electrofishi...

A common theme in recent landscape studies is the comparison of riparian and watershed land use as predictors of stream health. The objective of this study was to compare the performance of reach-scale habitat and remotely assessed watershed-scale habitat as predictors of stream health over varying spatial extents. Stream health was measured with scores on a fish index of biotic integrity (IBI)...

This thesis investigates the underlying mechanisms and the density-regulatory effects of age-class interactions, using juvenile Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) as study species. Field experiments were performed in streams along the western coast of Sweden, in which densities of older age-classes were reduced and the response on young-of-the-year habitat use an...

Mitigating stream and river impairment is complex, particularly in mixed-land-use watersheds given the likelihood of integrated responses of stream restoration to coupled and ongoing terrestrial ecosystem disturbance and the need for periodic reassessment and maintenance. Traditional biological sampling (e.g., macroinvertebrate sampling or other biological indices) alone seldom identifies the c...

1. Studies of North American streams have shown that hydraulic parameters and stream geomorphology can explain unionid mussel abundance at both the reach and catchment scale. However, few studies have examined applicability of hydrogeomorphic variables across broader spatial scales, such as across whole catchments, or have elucidated conditions under which spates can affect mussel populations i...

Background: Habitat characteristics can vary over small spatial scales at which gene flow is expected to swamp any effect of divergent natural selection. However, fine-grained (‘microgeographic’) adaptive divergence may still be feasible if individuals exhibit dispersal behaviours that improve the match between their phenotype and habitat. For example, threespine stickleback (Gasterosteus acule...

Small dams are ubiquitous yet poorly understood features in many streams. Dam removal is being used increasingly in stream restoration projects as a means to enhance habitat connectivity and ecosystem function. However, habitatand assemblage-level effects of small dams on stream mollusk assemblages are poorly documented. We examined associations between stream physicochemical habitat variables ...

Understanding how abundance regulates the effects of organisms on their ecosystems remains a critical goal of ecology, especially for understanding inter-ecosystem transfers of energy and nutrients. Here we examined how territoriality and nest-digging by anadromous salmon mediate trophic subsidies to stream fishes. Salmon eggs become available for consumption primarily by the digging of salmon ...