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Robert K Al-Chokhachy

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We collected diets on Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and brown trout (Salmo trutta) above (Yellowstone cutthroat trout allopatry) and below (Yellowstone cutthroat trout sympatry with brown trout) a natural barrier in Duck Creek, Montana. We used gastric lavage methods to collect diets, and samples were placed in storage containers and taken back to our lab and frozen until sorting. All samples were sorted by Rhithron, Inc. (Missoula, MT) with individuals identified down to the order.
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Abstract Unpaved forest roads remain a pervasive disturbance on public lands and mitigating sediment from road networks remains a priority for management agencies. Restoring roaded landscapes is becoming increasingly important for many native coldwater fishes that disproportionately rely on public lands for persistence. However, effectively targeting restoration opportunities requires a comprehensive understanding of the effects of roads across different ecosystems. Here, we combine a review and a field study to evaluate the status of knowledge supporting the conceptual framework linking unpaved forest roads with streambed sediment. Through our review, we specifically focused on those studies linking measures of...
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Project Overview: Native Yellowstone cutthroat trout and mountain whitefish in the Greater Yellowstone Ecosystem (GYA) are ecologically and socio-economically important species, but are threatened by drought, rising water temperatures, habitat loss, and non-native species. Researchers supported by this North Central CASC project will use climate data and extensive population records to assess the various threats to the species and to create a data visualization tool to help managers prioritize conservation actions for these vulnerable and valuable fish populations. Project Summary: In the Greater Yellowstone Area (GYA), drought, rising water temperatures, habitat loss, and non-native species are threatening the...
Field estimates of the abundance of rainbow trout in Washington and British Columbia were collected in concert with environmental DNA samples (eDNA) to evaluate if eDNA copy numbers correlated with abundance of trout. In addition, stream habitat data including channel units (pools, riffles), substrate, large woody debris, among others, were collected at sites.
Climate change may facilitate the expansion of non-native invasive species (NIS) in aquatic and terrestrial systems. However, empirical evidence remains scarce and poorly synthesized at scales necessary for effective management. We conducted a literature synthesis to assess the state of research on the observed and predicted effects of climate change on a suite of 398 aquatic and terrestrial NIS now present in or a major threat to aquatic and terrestrial ecosystems of the Pacific Northwest (PNW), USA and British Columbia. Surprisingly, very few studies (n = 15) have investigated the observed effects of climate change on the distribution, abundance, spread, or impact of the focal NIS, with only five studies focusing...
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