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During the past 30 years bull trout (Salvelinus confluentus ) populations have declined in various watersheds across their range. The decline has been attributed to loss of habitat, over harvesting, habitat disturbance from resource development activities, and interaction with exotic species. The declining population trends observed over the past three decades suggest that this species is sensitive to impacts. In response to these declines, bull trout are listed as "Threatened" in the United States and "Sensitive" in Alberta, British Columbia, and the Yukon Territory. In the Northwest Territories bull trout are listed as "May Be at Risk" and are a candidate for a detailed risk assessment in the area. The presence...
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Riverine sockeye salmon Oncorhynchus nerka (those that do not use nursery lakes for juvenile rearing) tend to be characterized by greater genetic diversity and weaker population structure than lake-type populations. These findings have led to the 'recurrent evolution' hypothesis for sockeye salmon life histories, which proposes that riverine sockeye salmon are the principal colonizing form and play the dominant role in the long-term persistence of sockeye salmon in a dynamic landscape. However, previous studies in Kamchatka (Russia) and Alaska have suggested that the general patterns of riverine sockeye salmon do not apply in all parts of the species' range. In this study, we examined genetic diversity and population...
Populations of Chinook salmon Oncorhynchus tshawytscha in the Yukon River declined by more than 57% between 2003 and 2010, probably the result of a combination of anthropogenic and environmental factors. One possible contributor to this decline is Ichthyophonus, a mesomycetozoan parasite that has previously been implicated in significant losses of fish, including Chinook salmon. A multiyear epidemiological study of ichthyophoniasis in the Yukon River revealed that disease prevalence and Chinook salmon population abundance increased and decreased simultaneously (i.e., were concordant) from 1999 to 2010. The two values rose and fell synchronously 91% of the time for female Chinook salmon and 82% of the time for males;...
Toxaphene is one of the major persistent organic pollutants with global environmental impacts. We have measured total toxaphene and specific congeners concentrations in 19 fish samples collected from the Yukon, Canada using gas chromatography coupled to ion trap MS/MS. The total toxaphene concentrations ranged from 42 to 242 ng/g (mean = 107+/-61 ng/g). The sum of the three specific congeners (Parlar 26, 50 and 62) was within 10-55 ng/g. The ratio of the sum of the three congeners to the total toxaphene varied between 8% and 25% in the fish samples but the ratio may be species specific. Our results suggest that consumption of these Yukon fish should have minimal risk of toxaphene exposure.
We present a case-study evaluation of gillnet catches of Walleye Sander vitreus to assess potential effects of large-scale changes in Oneida Lake, New York, including disruption of trophic interactions by double-crested cormorants Phalacrocorax auritus and invasive dreissenid mussels. We used the empirical long-term gillnet time series and a negative binomial linear mixed model to partition variability into spatial and coherent temporal variance components, and we propose that variance partitioning can help quantify spatiotemporal variability and examine if variance structure differs before and after large-scale perturbation. Here, we found that average catch and total variability of catches decreased following...
Although scientists have identified many ways to reduce the negative effects of climate change on wildlife, this information is not readily available to natural resource managers. For successful wildlife adaptation to climate change, natural resource managers should have current, peerreviewed information to guide their decisions. We conducted a review of over 1300 publications for recommendations to manage wildlife in the face of climate change. We then summarized the findings as the wildlife adaptation menu, a tool to inform planning and decision-making in an accessible format.
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Description: The upper Gila River in New Mexico is one of the few unobstructed rivers in the Colorado River Basin with largely intact native fish populations, including four federally listed and one state listed species.Freshwater systems throughout the West continue to be threatened by human encroachment and water development. Methodologies or decision support tools to evaluate resource management practices that foster an understanding of how fish species adapt to the effects of climate change are critical to future resource management planning.
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Stream fragmentation alters the structure of aquatic communities on a global scale, generally through loss of native species. Among riverscapes in the Great Plains of North America, stream fragmentation and hydrologic alteration (flow regulation and dewatering) are implicated in the decline of native fish diversity. This study documents the spatio–temporal distribution of fish reproductive guilds in the fragmented Arkansas and Ninnescah rivers of south-central Kansas using retrospective analyses involving 63 years of fish community data. Pelagic-spawning fishes declined throughout the study area during 1950–2013, including Arkansas River shiner (Notropis girardi) last reported in 1983, plains minnow (Hybognathus...
Categories: Data, Publication; Types: Citation, Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: CATFISHES/MINNOWS, Colorado, Colorado, FISH, Federal resource managers, All tags...
How do organisms diversify or "radiate" in nature? I studied an Alaskan threespine stickleback adaptive radiation to examine the rate at which organisms adapt to novel environmental conditions and the importance of different factors that facilitate or constrain adaptive radiation in nature. My dissertation research consisted of two main components. First, I exploited a recently established population in Loberg Lake to examine the rate and pattern of stickleback adaptation in nature. I established baseline phenotypic variation and covariation using its most likely ancestor, a sea-run population from the same drainage. Within 25 years of establishment, the Loberg Lake population evolved from the ancestral phenotype...
Coalbed methane is one of the most important and valuable natural resources in the Western United States. The natural gas that results from CBM development is the cleanest burning fossil fuel, and the extensive domestic supply makes it a central element of the national goal of a secure supply of energy. Demand for natural gas will continue to grow and CBM will play an increasingly larger role in meeting that demand. CBM production has expanded tremendously over the past decade, and the rapidity with which development has expanded has resulted in stresses and tension in affected communities. Development of this important energy resource must be balanced with a number of other important goals of protecting water,...
Abstract (from http://sp.lyellcollection.org/content/early/2015/10/09/SP408.11.abstract): We present a hierarchical series of spatially decreasing and temporally increasing models to evaluate the uncertainty in the atmosphere – ocean global climate model (AOGCM) and the regional climate model (RCM) relative to the uncertainty in the somatic growth of the endangered pallid sturgeon (Scaphirhynchus albus). For effects on fish populations of riverine ecosystems, climate output simulated by coarse-resolution AOGCMs and RCMs must be downscaled to basins to river hydrology to population response. One needs to transfer the information from these climate simulations down to the individual scale in a way that minimizes extrapolation...
map background search result map search result map Distribution, life history, and habitat use of bull trout ( Salvelinus confluentus) in mountain streams of the southern and central Northwest Territories Lake characteristics and species inventory and distribution for 11 Interior Alaska lakes, 2005-2008 Genetic Diversity and Population Structure in the Kuskokwim River Drainage Support the Recurrent Evolution Hypothesis for Sockeye Salmon Life Histories Science Brief for Resource Managers: Metacommunity Dynamics of Gila River Fishes Publication: Fragmentation and drying ratchet down Great Plains stream fish diversity Science Brief for Resource Managers: Metacommunity Dynamics of Gila River Fishes Lake characteristics and species inventory and distribution for 11 Interior Alaska lakes, 2005-2008 Distribution, life history, and habitat use of bull trout ( Salvelinus confluentus) in mountain streams of the southern and central Northwest Territories Genetic Diversity and Population Structure in the Kuskokwim River Drainage Support the Recurrent Evolution Hypothesis for Sockeye Salmon Life Histories Publication: Fragmentation and drying ratchet down Great Plains stream fish diversity