Throughout the world, efforts are under way to restore watersheds, but restoration planning rarely accounts for future climate change. Using a series of linked models climate, land cover, hydrology, and salmon population dynamics, we investigated impacts change on effectiveness proposed habitat designed recover depleted Chinook populations in Pacific Northwest river basin. Model results indicate large negative impact freshwater habitat. Habitat protection can help mitigate these effects may...

Current efforts to conserve Pacific salmon (Oncorhynchus spp.) rely on a variety of information sources, including empirical observations, expert opinion, and models. Here we outline framework for incorporating detailed density-dependent population growth, habitat attributes, hatchery operations, harvest management into conservation planning in time-varying, spatially explicit manner. We multistage Beverton–Holt model describe the production from one life stage next. use literature construct...

Dams designed for hydropower and other purposes alter the environments of many economically important fishes, including Chinook salmon (Oncorhynchus tshawytscha). We estimated that dams on Rogue River, Willamette Cowlitz Fall Creek decreased water temperatures during summer increased fall winter. These thermal changes undoubtedly impact behavior, physiology, life histories salmon. For example, relatively high winter should speed growth development, leading to early emergence fry....

Lake Clark is an important nursery lake for sockeye salmon (Oncorhynchus nerka) in the headwaters of Bristol Bay, Alaska, most productive wild fishery world. Reductions water clarity within Alaska systems as a result increased glacial runoff have been shown to reduce production via reduced abundance zooplankton and macroinvertebrates. In this study, we reconstruct long-term, lake-wide using Landsat TM ETM+ surface reflectance products (1985–2014) situ data collected between 2009 2013....

One of the challenges associated with recovering imperiled species, such as Chinook salmon (Oncorhynchus tshawytscha), is identifying a set actions that will ensure species' persistence. Here we evaluate effects alternative land use scenarios on habitat conditions potentially important to salmon. We first summarize target levels for certain characteristics. then estimate changes in current conditions. The explore indicate considerable potential improve both quality and quantity through...

Abstract The combined effects of water diversion and climate change are a major conservation challenge for freshwater ecosystems. In the Lemhi Basin, Idaho (U.S.A.), causes changes in streamflow, will further affect streamflow temperature. Shifts temperature regimes can juvenile salmon growth, movement, survival. We examined potential on Chinook (Oncorhynchus tshawytscha), species listed as threatened under U.S. Endangered Species Act (ESA). To examine survival, we created model relating 19...

We applied an empirical model to predict hatching and emergence timing for 25 western Alaska sockeye salmon (Oncorhynchus nerka) populations in four lake-nursery systems explore current patterns potential responses of early life history phenology warming water temperatures. Given the temperature regimes experienced during development, we predicted occur as few 58 days many 260 depending on spawning temperature. For a focal lake population, our climate–lake increase 0.7 1.4 °C from 2015 2099...

Chinook salmon (Oncorhynchus tshawytscha) have declined dramatically across the Pacific Northwest because of multiple human impacts colloquially characterized as four "H's": habitat degradation, harvest, hydroelectric and other dams, hatchery production. We use this conceptual framework to quantify relative importance major threats current status 201 populations. Current is by two demographic indices: population density trend. employ path analytic models information theoretic methods for...

For widely distributed species at risk, such as Pacific salmon (Oncorhynchus spp.), habitat monitoring is both essential and challenging. Only recently have widespread programs been implemented for in the Northwest. Remote sensing data, Landsat images, are therefore a useful way to evaluate trends prior advent of species-specific programs. We used annual (1986-2008) land cover maps created from images via automated algorithms (LandTrendr) developed (50-100% impervious) areas adjacent five...

Lake trout (Salvelinus namaycush), collected from 13 remote lakes located in southwestern Alaska, were analyzed for carbon, nitrogen, and mercury (Hg) stable isotope values to assess the importance of migrating oceanic salmon, volcanic activity, atmospheric deposition fish Hg burden. Methylmercury (MeHg) bioaccumulation phytoplankton (5.0 - 6.9 kg L-1) was also measured quantify basal uptake MeHg these aquatic food webs. lake revealed that while extent precipitation-delivered similar across...

Abstract Invasive species introductions in high latitudes are accelerating and elevating the need to address questions of their effects on Subarctic Arctic ecosystems. As a driver ecosystem function, submerged aquatic vegetation is one most deleterious biological invasions food webs. The plant Elodea spp. has potential be widespread invader ecosystems already established 19 waterbodies Alaska, USA. been found alter processes through multiple pathways; yet little known about impact fish life...

Mercury (Hg) is a widespread element and persistent pollutant, harmful to fish, wildlife, humans in its organic, methylated form. The risk of Hg contamination driven by factors that regulate loading, methylation, bioaccumulation, biomagnification. In remote locations, with infrequent access limited data, understanding the relative importance these can pose challenge. Here, we assessed concentrations an apex predator fish species, lake trout (Salvelinus namaycush), collected from 14 lakes...

Management or conservation targets based on demographic rates should be evaluated within the context of expected population dynamics species interest. Wild populations can experience stable, cyclical, complex dynamics, therefore undisturbed provide background needed to evaluate programmatic success. Many raptor have recovered from large declines caused by environmental contaminants, making them strong candidates for ongoing efforts understand and ecosystem processes in response human-caused...

Abstract In high‐latitude lakes, air temperature is an important driver of ice cover thickness and duration, which in turn influence water primary production supporting lake consumers predators. lieu multidecadal observational records necessary to assess the response lakes long‐term warming, we used otolith‐based growth from a long‐lived resident fish, trout ( Salvelinus namaycush), as proxy for production. Lake were collected seven deep, oligotrophic Clark National Park Preserve on...

A huge proportion of the world’s population resides in urban areas along coast. As cities expand, ability coastal ecosystems to provide benefits people derive from nature, ranging food fisheries defense maritime transportation and beyond, is question. While it well understood that development changes ecosystems, quantitative insights about how terrestrial urbanization fundamentally alters ecosystem structure function adjacent freshwater downstream marine habitats remain rare, though a...