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The addition of limestone sand directly to streams is an effective method for treating chemical and biological issues associated with acid precipitation, a common concern in many Appalachian watersheds. The unique water chemistry created by limestone remediation potentially creates a "mark" in fish hard parts (e.g., otoliths and fin rays) that can be used to identify fish from remediated habitats, even after fish disperse into the surrounding riverscape. We tested whether elevated concentrations of calcium from a limestone‐treated stream could be identified by microchemistry in the otoliths of Brook Trout Salvelinus fontinalis and whether the concentrations could distinguish fish among treated and untreated habitats within the upper Shavers Fork watershed in West Virginia. Calcium concentrations in water were similar between the treated headwater stream and the control stream. Multivariate ANOVA and Bonferroni post hoc analyses indicated that calcium and strontium concentrations were significantly higher in Brook Trout otoliths from the treatment stream than in those from the control stream. Our results suggest that hard‐part microchemistry is a promising tool for identifying locally produced fish from limestone‐remediated streams in the surrounding riverscape. [ABSTRACT FROM AUTHOR]

We used direct observation via snorkeling surveys to quantify microhabitat use by native brook (Salvelinus fontinalis) and non‐native brown (Salmo trutta) and rainbow (Onchorynchus mykiss) trout occupying natural and restored pool habitats within a large, high‐elevation Appalachian river, United States. Permutational multivariate analysis of variance (PERMANOVA) and subsequent two‐way analysis of variance (ANOVA) indicated a significant difference in microhabitat use by brook and non‐native trout within restored pools. We also detected a significant difference in microhabitat use by brook trout occupying pools in allopatry versus those occupying pools in sympatry with non‐native trout—a pattern that appears to be modulated by size. Smaller brook trout often occupied pools in the absence of non‐native species, where they used shallower and faster focal habitats. Larger brook trout occupied pools with, and utilized similar focal habitats (i.e. deeper, slower velocity) as, non‐native trout. Non‐native trout consistently occupied more thermally suitable microhabitats closer to cover as compared to brook trout, including the use of thermal refugia (i.e. ambient–focal temperature >2°C). These results suggest that non‐native trout influence brook trout use of restored habitats by: (1) displacing smaller brook trout from restored pools, and (2) displacing small and large brook trout from optimal microhabitats (cooler, deeper, and lower velocity). Consequently, benefits of habitat restoration in large rivers may only be fully realized by brook trout in the absence of non‐native species. Future research within this and other large river systems should characterize brook trout response to stream restoration following removal of non‐native species. [ABSTRACT FROM AUTHOR]

Fragmentation of aquatic habitats is a global conservation concern. Losses of both biodiversity and genetic diversity have been attributed to this phenomenon as dispersal movements between habitat patches are restricted. Brook Trout Salvelinus fontinalis in the upper Shavers Fork watershed of West Virginia exhibit high dispersal rates and lengthy dispersal distances; however, road culverts have been hypothesized to influence the movement of Brook Trout between tributaries. Removing impassable culverts could serve as a tool to facilitate movements into previously isolated streams. We classified the passability of road culverts by their physical attributes and collected samples above each structure as well as in two streams without culverts to test for genetic population differentiation attributed to culverts. After we determined that the majority of streams consisted of a single genetic population, with the exception of two streams containing culverts designated as impassable (Beaver Creek and Lamothe Hollow), the culvert structures were restored to eliminate outlets perched above the stream bottom and were subsequently resampled 1 year after project completion. Although no individuals were assigned as first-generation migrants into either Beaver Creek or Lamothe Hollow before culvert restoration, five individuals were detected as first-generation migrants into Beaver Creek (13%), and one individual was identified as a first-generation migrant into Lamothe Hollow (4.5%) after culvert restoration. Three different streams were found to be sources of the migrants into Beaver Creek, and the single individual migrating into Lamothe Hollow was from a fourth source stream. The identification of first-generation migrants through genetic assignment not only provides a tool with which to test the effectiveness of barrier removal and subsequent restoration success but also to support the importance of culvert replacement in headwater streams. [ABSTRACT FROM AUTHOR]

We conducted a large-scale assessment of unconventional oil and gas (UOG) development effects on brook trout ( Salvelinus fontinalis ) distribution. We compiled 2231 brook trout collection records from the Upper Susquehanna River Watershed, USA. We used boosted regression tree (BRT) analysis to predict occurrence probability at the 1:24,000 stream-segment scale as a function of natural and anthropogenic landscape and climatic attributes. We then evaluated the importance of landscape context (i.e., pre-existing natural habitat quality and anthropogenic degradation) in modulating the effects of UOG on brook trout distribution under UOG development scenarios. BRT made use of 5 anthropogenic (28% relative influence) and 7 natural (72% relative influence) variables to model occurrence with a high degree of accuracy [Area Under the Receiver Operating Curve (AUC) = 0.85 and cross-validated AUC = 0.81]. UOG development impacted 11% ( n = 2784) of streams and resulted in a loss of predicted occurrence in 126 (4%). Most streams impacted by UOG had unsuitable underlying natural habitat quality ( n = 1220; 44%). Brook trout were predicted to be absent from an additional 26% ( n = 733) of streams due to pre-existing non-UOG land uses (i.e., agriculture, residential and commercial development, or historic mining). Streams with a predicted and observed (via existing pre- and post-disturbance fish sampling records) loss of occurrence due to UOG tended to have intermediate natural habitat quality and/or intermediate levels of non-UOG stress. Simulated development of permitted but undeveloped UOG wells ( n = 943) resulted in a loss of predicted occurrence in 27 additional streams. Loss of occurrence was strongly dependent upon landscape context, suggesting effects of current and future UOG development are likely most relevant in streams near the probability threshold due to pre-existing habitat degradation. [ABSTRACT FROM AUTHOR]

Pristine streams are often targeted as conservation priorities because of their ability to preserve regional biodiversity. However, isolation within heavily degraded regions likely alters important metapopulation and metacommunity processes (e.g., rescue and mass effects), affecting the ability of in-tact communities to boost regional conditions. To test this hypothesis, we sampled invertebrate communities and physicochemical conditions from 168 streams within the mountaintop removal-valley fill mining region of West Virginia. We used redundancy analysis to first test for significant effects of local (observed physicochemical conditions) and neighborhood (streams within a 5 km buffer) degradation on assemblage structure across all taxa and stress tolerance (low, moderate, high) and dispersal (low, high) categories. We then used generalized linear and hurdle models to characterize changes in community metrics and individual taxa, respectively. Local condition consistently explained the majority of variation (partial R 2 up to 5 × those of neighborhood condition) in community structure and was the only factor affecting sensitive taxa. Neighborhood condition explained significant variation in moderately tolerant taxa with low dispersal capacity and highly tolerant taxa, regardless of dispersal. Decreased occurrence ( Baetis ) and abundance ( Maccaffertium ) of key taxa and corresponding metrics (%E, %EPT) suggest decreased dispersal and associated mass and rescue effects within degraded neighborhoods. Decreased neighborhood conditions also resulted in the proliferation of tolerant taxa (Chironomidae, Chimarra , Hemerodromia ). Our results suggest communities within even the most pristine streams are at risk when isolated within heavily impacted regions. Consequently, protection of regional species' pools in heavily impacted regions will require more than simply conserving un-impacted streams. [ABSTRACT FROM AUTHOR]

Runoff from watersheds altered by mountaintop mining in the Appalachian region (USA) is known to pollute headwater streams, yet regional-scale assessments of water quality have focused on salinization and selenium. The authors conducted a comprehensive survey of inorganic contaminants found in 170 stream segments distributed across a spectrum of historic and contemporary human land use. Principal component analysis identified 3 important dimensions of variation in water chemistry that were significantly correlated with contemporary surface mining (principal component 1: elevated dominant ions, sulfate, alkalinity, and selenium), coal geology and legacy mines (principal component 2: elevated trace metals), and residential development (principal component 3: elevated sodium and chloride). The combination of these 3 dominant sources of pollutants produced a complex stream-to-stream patchwork of contaminant mixtures. Seventy-five percent of headwater streams (catchments < 5 km2) had water chemistries that could be classified as either reference (49%), development only (18%), or mining only (8%). Only 21% of larger streams (catchments > 5 km2) were classified as having reference chemistries, and chemistries indicative of combined mining and development contaminants accounted for 47% of larger streams (compared with 26% of headwater streams). Extreme degradation of larger streams can be attributed to accumulation of contaminants from multiple human land use activities that include contemporary mountaintop mining, underground mining, abandoned mines, and untreated domestic wastewater. Consequently, water quality improvements in this region will require a multicontaminant remediation approach. Environ Toxicol Chem 2015;34:2603-2610. © 2015 SETAC [ABSTRACT FROM AUTHOR]

Spatial population models predict strong density-dependence and relatively stable population dynamics near the core of a species' distribution with increasing variance and importance of density-independent processes operating towards the population periphery. Using a 10-year data set and an information-theoretic approach, we tested a series of candidate models considering density-dependent and density-independent controls on brook trout population dynamics across a core-periphery distribution gradient within a central Appalachian watershed. We sampled seven sub-populations with study sites ranging in drainage area from 1.3–60 km2 and long-term average densities ranging from 0.335–0.006 trout/m. Modeled response variables included per capita population growth rate of young-of-the-year, adult, and total brook trout. We also quantified a stock-recruitment relationship for the headwater population and coefficients of variability in mean trout density for all sub-populations over time. Density-dependent regulation was prevalent throughout the study area regardless of stream size. However, density-independent temperature models carried substantial weight and likely reflect the effect of year-to-year variability in water temperature on trout dispersal between cold tributaries and warm main stems. Estimated adult carrying capacities decreased exponentially with increasing stream size from 0.24 trout/m in headwaters to 0.005 trout/m in the main stem. Finally, temporal variance in brook trout population size was lowest in the high-density headwater population, tended to peak in mid-sized streams and declined slightly in the largest streams with the lowest densities. Our results provide support for the hypothesis that local density-dependent processes have a strong control on brook trout dynamics across the entire distribution gradient. However, the mechanisms of regulation likely shift from competition for limited food and space in headwater streams to competition for thermal refugia in larger main stems. It also is likely that source-sink dynamics and dispersal from small headwater habitats may partially influence brook trout population dynamics in the main stem. [ABSTRACT FROM AUTHOR]

We quantified movements of brook trout Salvelinus fontinalis and brown trout Salmo trutta in a complex riverscape characterized by a large, open-canopy main stem and a small, closed-canopy tributary in eastern West Virginia, USA. Our objectives were to quantify the overall rate of trout movement and relate movement behaviors to variation in streamflow, water temperature, and access to coldwater refugia. The study area experienced extremely high seasonal, yearly, and among-stream variability in water temperature and flow. The relative mobility of brook trout within the upper Shavers Fork watershed varied significantly depending on whether individuals resided within the larger main stem or the smaller tributary. The movement rate of trout inhabiting the main stem during summer months (50 m/d) was an order of magnitude higher than that of tributary fish (2 m/d). Movement rates of main-stem-resident brook trout during summer were correlated with the maximum water temperature experienced by the fish and with the fish's initial distance from a known coldwater source. For main-stem trout, use of microhabitats closer to cover was higher during extremely warm periods than during cooler periods; use of microhabitats closer to cover during warm periods was also greater for main-stem trout than for tributary inhabitants. Main-stem-resident trout were never observed in water exceeding 19.5°C. Our study provides some of the first data on brook trout movements in a large Appalachian river system and underscores the importance of managing trout fisheries in a riverscape context. Brook trout conservation in this region will depend on restoration and protection of coldwater refugia in larger river main stems as well as removal of barriers to trout movement near tributary and main-stem confluences. Received September 16, 2011; accepted March 23, 2012 [ABSTRACT FROM PUBLISHER]

Throughout the Central Appalachians of the United States resource extraction primarily from coal mining has contributed to the majority of the forest conversion to barren and reclaimed pasture and grass. The loss of forests in this ecoregion is significantly impacting biodiversity at a regional scale. Since not all forest stands provide equal levels of ecological functions, it is critical to identify and map existing forested resources by the benefits that accrue from their unique spatial patterns, watershed drainage, and landscape positions. We utilized spatial analysis and remote sensing techniques to define critical forest characteristics. The characteristics were defined by applying a forest fragmentation model utilizing morphological image analysis, defining headwater catchments at a 1 : 24,000 scale, and deriving ecological land units (ELUs) from elevation data. Once critical forest values were calculated, it was possible to identify clusters of critical stands using spatial statistics. This spatially explicit method for modeling forest habitat could be implemented as a tool for assessing the impact of resource extraction and aid in the conservation of critical forest habitat throughout a landscape. [ABSTRACT FROM AUTHOR]

As watershed-scale studies of stream fishes become increasingly common, there is a need for more accurate estimation of fish population abundance and size structure with single-pass electrofishing techniques. Capture efficiencies are known to vary considerably across habitats and species, yet few studies have quantified or provided a logical framework for accounting for this variability. Consequently, our objectives were to (1) determine which species and which size-classes within species exhibited significant site-to-site variation in electrofishing efficiency and (2) construct models to predict species- and size-specific capture probability from physicochemical parameters. We used three-pass removal sampling to capture fishes from 40 study sites located in wadeable streams in the Cheat River and Tygart Valley River watersheds of West Virginia. The program MARK was used to estimate capture probabilities for 12 commonly sampled fishes, to assess among-site variability in capture probability, and to model variability in capture probability as a function of fish size and readily measured environmental covariates. Our results indicated that for most species sampled (9 of 12), some combination of these covariates-mean stream width, gradient, specific conductivity, and species size-class-could be used to produce a model of capture probability superior to the most complex model that accounted for site-to-site variability in capture probability. One species demonstrated constant capture probability among sites, and two others exhibited significant site-to-site variation in capture probability that could not be accounted for using any of the measured covariates. Our results provide a basis for using single-pass electrofishing data to infer population-level phenomena (e.g., relative abundance, size structure) in watershed-scale studies of stream fish assemblages. [ABSTRACT FROM AUTHOR]

1. We used information theoretic statistics [Akaike’s Information Criterion (AIC)] and regression analysis in a multiple hypothesis testing approach to assess the processes capable of explaining long-term demographic variation in a lightly exploited brook trout population in Ball Creek, NC. We sampled a 100-m-long second-order site during both spring and autumn 1991–2004, using three-pass electrofishing. 2. Principle component analysis indicated that the site had lower average velocity, greater amounts of depositional substrata and lower amount of erosional substrata during the 1999–2002 drought than in non-drought years. In addition, drought years had lower flows, and lower variation in flows, than non-drought years. 3. Both young-of-the-year (YOY) and adult densities varied by an order of magnitude during the study. AIC analysis conducted on regressions of per capita rate of increase versus various population and habitat parameters for the population, adults and YOY, for both spring and autumn data sets, indicated that simple density dependence almost always was the only interpretable model with Akaike weights ( wi) ranging from 0.262 to 0.836. 4. Growth analyses yielded more variable results, with simple density dependence being the only interpretable model for both adult spring data ( wi = 0.999) and YOY autumn data ( wi = 0.905), and positive density dependence ( wi = 0.636) and simple density independence ( wi = 0.241) representing interpretable models for spring YOY data. 5. We detected a significant stock–recruitment relationship between both spring and autumn densities of adults in year t and autumn YOY density in year t + 1. Finally, spring YOY density was positively correlated with both autumn YOY density and spring mean YOY standard length (SL), suggesting that processes affecting recruitment show residual effects at least in the first year of life. This population appears to be regulated primarily by density-dependent processes, although high flows also negatively affected mean SLs of YOY. [ABSTRACT FROM AUTHOR]

1. We used observational and experimental field studies together with an individual-based simulation model to demonstrate that behaviours of mottled sculpin ( Cottus bairdi) were broadly consistent with the expectations of Giving-Up Density theory and an Ideal Pre-emptive Distribution habitat selection model. 2. Specifically we found that: (i) adult mottled sculpin established territories within patches characterised by significantly higher prey densities and prey renewal rates than patches occupied by juveniles or randomly selected patches; (ii) patches abandoned by adult sculpin possessed significantly lower prey densities than newly occupied patches, although this was not true for juveniles; (iii) the observed giving-up density (GUD) for adult sculpin (i.e. average prey density in patches recently abandoned) increased linearly with increasing fish size up to the average prey density measured in randomly selected patches (i.e. 350 prey items per 0.1 m2) and decreased with increasing sculpin density and (iv) juveniles rapidly shifted their distribution towards the highest quality patches following removal of competitively dominant adult sculpin. 3. These results provide the first evidence of the applicability of GUD theory to a stream-dwelling organism, and they elucidate the underlying factors influencing juvenile and adult sculpin habitat selection and movement behaviours. Furthermore, optimal patch use, ideal pre-emptive habitat selection and juvenile ‘floating’ provide behavioural mechanisms linking environmental heterogeneity in the stream benthos to density-dependent regulation of mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]

We developed and validated a predictive model of water temperature that could be applied to mapped stream segments in a West Virginia, USA watershed. We then tested the hypothesis that local water temperature and the topology of stream thermal networks interact to determine the distribution of two fishes known to differ in their thermal preference - smallmouth bass (Micropterus dolomieu) and brook trout (Salvelinus fontinalis). Two measures of regional thermal topology were constructed -- mean distance to the nearest five coldwater stream segments and distance to the nearest warmwater stream segment. Consistent with expectations, brook trout were more likely to be found in colder streams, and smallmouth bass were in wanner streams. However, brook trout distributions were statistically independent of the regional thermal context suggesting that regional thermal conditions have less influence on brook trout than local thermal conditions in this system. In contrast, there was a significant effect of stream network topology on the distribution of smallmouth bass. Bass were often present in coolwater streams located in close proximity to warmwater mainstems but not in coolwater streams highly isolated from warm water. Furthermore, sympatry in these two species was associated with cool- and coldwater streams located in close proximity to warmwater streams. These findings indicate that overall fish assemblage response to thermal conditions may be the result of species-specific responses to both local thermal conditions and the regional topology of cold, cool, and warmwater streams. [ABSTRACT FROM AUTHOR]

Large-scale culvert replacement programs could benefit migratory fish populations by reconnecting reproductive and foraging habitats in fragmented watersheds. The objectives of this study were to: (1) identify stream and culvert characteristics contributing to fish passage barriers within an Appalachian watershed, U.S.A.; (2) quantify the total amount of Brook trout ( Salvelinus fontinalis) reproductive habitat isolated above culverts; and (3) use an ecological currency to identify culvert replacement priorities and stream mitigation credit opportunities. We surveyed 120 state-owned culverts and used a fish passage assessment filter to determine the “passability” of each culvert. We then constructed a geographic information system stream network model to quantify the amount of trout reproductive habitat isolated by culverts. Ninety-seven percent of surveyed culverts were classified as obstacles or complete barriers to trout dispersal. Culvert impassability was higher in small streams with slopes exceeding 3–5%, suggesting a direct relationship between slope and impassability. Thirty-three percent of Brook trout reproductive habitat, representing over 200 km of stream, was isolated by culverts. This is a conservative estimate, because we did not survey privately or federally owned culverts. The top 20 prioritized culverts accounted for nearly half of the habitat loss. Our results indicate that standard culvert designs placed in streams with slopes exceeding 5% consistently produce trout dispersal barriers and should be avoided during new road construction. The process developed here provides an efficient method for identifying culvert replacement priorities and may be used to maximize watershed scale benefits of stream restoration. [ABSTRACT FROM AUTHOR]

We quantified the space use behaviors of juvenile and adult mottled sculpin over a 3-year period in Shope Fork, western North Carolina. Our objectives were to (1) quantify home range size, (2) determine whether the fish exhibit territorial behaviors, (3) characterize the relative stability of territories, and (4) relate temporal variation in behaviors to environmental variability and population size structure. Adult behaviors were consistent with those of a strongly territorial organism. Adults exhibited nonrandom movements, restricted home ranges, and extremely low levels of spatial overlap with neighboring residents (<10% overlap). Territories were established in erosional microhabitats that were significantly more stable (as measured by seasonal shifts in dominant substrate composition) than randomly selected microhabitats in the study site. In contrast to adults, juveniles did not exhibit evidence of territoriality and instead occupied overlapping home ranges (16-36% overlap) in less-stable, depositional microhabitats along the stream margin. Mottled sculpin home range size, home range overlap, and territory abandonment rate were related to the density of large adults rather than flow variability or microhabitat stability. Adult territoriality and juvenile floating provide behavioral mechanisms capable of producing strong regulation of mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]

We analyzed seasonal water samples from the Cheat and Tygart Valley river basins, West Virginia, USA, in an attempt to classify streams based on water chemistry in this coal-mining region. We also examined temporal variability among water samples. Principal component analysis identified two important dimensions of variation in water chemistry. This variation was determined largely by mining-related factors (elevated metals, sulfates, and conductivity) and an alkalinity-hardness gradient. Cluster analysis grouped water samples into six types that we described as reference, soft, hard, transitional, moderate acid mine drainage, and severe acid mine drainage. These types were statistically distinguishable in multidimensional space. Classification tree analysis confirmed that chemical constituents related to acid mine drainage and acid rain distinguished these six groups. Hard, soft, and severe acid mine drainage type streams were temporally constant compared to streams identified as reference, transitional, and moderate acid mine drainage type, which had a greater tendency to shift to a different water type between seasons. Our research is the first to establish a statistically supported stream classification system in mined watersheds. The results suggest that human-related stressors superimposed on geology are responsible for producing distinct water quality types in this region as opposed to more continuous variation in chemistry that would be expected in an unimpacted setting. These findings provide a basis for simplifying stream monitoring efforts, developing generalized remediation strategies, and identifying specific remediation priorities in mined Appalachian watersheds. [ABSTRACT FROM AUTHOR]

The extent of impairment to some Appalachian watersheds from acid precipitation is so extreme that watershed scale analytical tools are needed to help guide cost-effective management decisions. The objective of this study was to develop a measure of the functional value of streams as potential areas for juvenile Brook trout recruitment. This measure, which we term“weighted potential recruitment area” (WPRA), is a function of the expected Brook trout spawning intensity and juvenile survivorship. Estimates of WPRA for each stream segment were then used to identify restoration priorities and optimal restoration programs in the upper Shavers Fork watershed in West Virginia, U.S.A. Using this approach, we determined that the watershed has lost nearly 80% of its historic juvenile recruitment potential as a result of acid precipitation. We also determined that of the 145 stream segments in the watershed, eight critical stream segments account for nearly 20% of the loss. The costs and ecological benefits of a series of five alternative restoration programs were then assessed using an ArcGIS model (Environmental Systems Research Institute, Redlands, CA, U.S.A.). This approach identified two“optimal” alternatives: (1) a low-cost, moderate-benefit approach that would use existing rail access to treat acidification in three critical headwater locations and (2) a high-cost, high-benefit approach that would use aerial limestone application to treat numerous acidic tributaries near their source. The measure of stream ecological value that we developed was effective in identifying critical restoration priorities and optimal restoration strategies in this watershed. A similar procedure could be used to guide watershed restoration decisions throughout the Appalachian region. [ABSTRACT FROM AUTHOR]

We quantified the watershed-scale spatial population dynamics of brook trout in the Second Fork, a third-order tributary of Shavers Fork in eastern West Virginia. We used visual surveys, electrofishing, and mark-recapture techniques to quantify brook trout spawning intensity, population density, size structure, and demographic rates (apparent survival and immigration) throughout the watershed. Our analyses produced the following results. Spawning by brook trout was concentrated in streams with small basin areas (i.e., segments draining less than 3 km2), relatively high alkalinity (>10 mg CaCO3/L), and high amounts of instream cover. The spatial distribution of juvenile and small-adult brook trout within the watershed was relatively stable and was significantly correlated with spawning intensity. However, no such relationship was observed for large adults, which exhibited highly variable distribution patterns related to seasonally important habitat features, including instream cover, stream depth and width, and riparian canopy cover. Brook trout survival and immigration rates varied seasonally, spatially, and among size-classes. Differential survival and immigration tended to concentrate juveniles and small adults in small, alkaline streams, whereas dispersal tended to redistribute large adults at the watershed scale. Our results suggest that spatial and temporal variations in spawning, survival, and movement interact to determine the distribution, abundance, and size structure of brook trout populations at a watershed scale. These results underscore the importance of small tributaries for the persistence of brook trout in this watershed and the need to consider watershed-scale processes when designing management plans for Appalachian brook trout populations. [ABSTRACT FROM AUTHOR]

1. We used direct observation and mark-recapture techniques to quantify movements by mottled sculpins (Cottus bairdi) in a 1 km segment of Shope Fork in western North Carolina. Our objectives were to: (i) quantify the overall rate of sculpin movement, (ii) assess variation in movement among years, individuals, and sculpin size classes, (iii) relate movement to variation in stream flow and population size structure, and (iv) quantify relationships between movement and individual growth rates. 2. Movements were very restricted: median and mean movement distances for all sculpin size classes over a 45 day period were 1.3 and 4.4 m respectively. Nevertheless, there was a high degree of intrapopulation and temporal variation in sculpin movement. Movement of juveniles increased with discharge and with the density of large adults. Movement by small and large adults was not influenced by stream flow, but large adults where more mobile when their own density was high. Finally, there were differences in the growth rates of mobile and sedentary sculpins. Mobile juveniles grew faster than sedentary individuals under conditions of low flow and high density of large adults, whereas adults exhibited the opposite pattern. 3. Our results support the hypothesis that juvenile movement and growth is influenced by both intraspecific interactions with adults and stream flow. In contrast, adult movement appears to be influenced by competitive interactions among residents for suitable space. The relationship between movement and growth may provide a negative feedback mechanism regulating mottled sculpin populations in this system. [ABSTRACT FROM AUTHOR]

1. We examined the response of a predatory benthic fish, the longnose dace (Rhinichthys cataractae), to patchiness in the distribution of benthic macroinvertebrates on cobbles at three hierarchical spatial scales during summer and autumn 1996, and spring 1997 in a southern Appalachian stream. 2. At the primary scale (four to five individual cobbles separated by <1 m), the intensity of foraging was not correlated with the biomass of benthic macroinvertebrates/cobble, regardless of season. 3. At the secondary scale (i.e. foraging patches <5 m in diameter) we found that benthic macroinvertebrates were patchily distributed in summer, but not in autumn or spring. Concomitantly, in summer, longnose dace foraged on cobbles with a significantly higher biomass of benthic macronvertebrates than nearby, randomly selected cobbles with similar physical conditions (i.e. longnose dace tended to avoid low-prey foraging patches). In contrast, when benthic macroinvertebrates were distributed homogeneously (spring and autumn), dace did not select patches with a significantly higher biomass of benthic macroinvertebrates than that available on randomly selected cobbles. 4. At the tertiary scale (i.e. stream reaches 11–19 m long), the biomass of benthic macroinvertebrates (per cobble per reach) was patchily distributed (i.e. differed significantly among reaches) in all seasons. Among reaches with physical characteristics preferred by longnose dace, (i.e. erosional reaches dominated by cobble/boulder substratum and high current velocity), we detected a significant, positive correlation between the biomass of benthic macroinvertebrates/cobble and longnose dace density in all seasons. 5. Our results demonstrated that both spatial and temporal patchiness in resource availability influenced significantly the use of both foraging patches and stream reaches by longnose dace. [ABSTRACT FROM AUTHOR]

Widespread salinization—and, in a broader sense, an increase in all total dissolved solids (TDS)—is threatening freshwater ecosystems and the services they provide (e.g., drinking water provision). We used a mixed modeling approach to characterize long-term (2010–2018) spatio-temporal variability in TDS within the Monongahela River basin and used this information to assess the extent and drivers of vulnerability. The West Fork River was predicted to exceed 500 mg/L a total of 133 days. Occurrence and duration (maximum = 28 days) of—and thus vulnerability to—exceedances within the West Fork River were driven by low flows. Projected decreases in mean daily discharge by ≤10 cfs resulted in an additional 34 days exceeding 500 mg/L. Consistently low TDS within the Tygart Valley and Cheat Rivers reduced vulnerability of the receiving Monongahela River to elevated TDS which was neither observed (maximum = 419 mg/L) nor predicted (341 mg/L) to exceed the secondary drinking water standard of 500 mg/L. Potential changes in future land use and/or severity of low-flow conditions could increase vulnerability of the Monongahela River to elevated TDS. Management should include efforts to increase assimilative capacity by identifying and decreasing sources of TDS. Upstream reservoirs could be managed toward low-flow thresholds; however, further study is needed to ensure all authorized reservoir purposes could be maintained. [ABSTRACT FROM AUTHOR]

We developed a multi‐scale conservation planning framework for brook trout (Salvelinus fontinalis) within the Chesapeake Bay watershed that incorporates both land use and climate stressors. Our specific objectives were to (1) construct a continuous spatial model of brook trout distribution and habitat quality at the stream reach scale; (2) characterize brook trout vulnerability to climate change under a range of future climate scenarios; and (3) identify multi‐scale restoration and protection priorities for brook trout across the Chesapeake Bay watershed. Boosted regression tree analysis predicted brook trout occurrence at the stream reach scale with a high degree of accuracy (CV AUC = 0.92) as a function of both natural (e.g., water temperature and precipitation) and anthropogenic (e.g., agriculture and urban development) landscape and climatic attributes. Current land use activities result in a predicted loss of occurrence in over 11,000 stream segments (40% of suitable habitat) and account for over 15,000 km (45% of current value) of lost functional brook trout fishery value (i.e., length‐weighted occurrence probability) in the Chesapeake Bay watershed. Climate change (increased ambient temperatures and altered precipitation) is projected to result in a loss of occurrence in at least 3000 additional segments (19% of current value) and at least 3000 km of functional fishery value (9% of current value) by 2062. Model outcomes were used to identify low‐ and high‐quality stream segments within relatively intact and degraded sub‐watersheds as restoration and protection priorities, respectively, and conservation priorities were targeted in watersheds with high projected resilience to climate change. Our results suggest that traditional restoration activities, such as habitat enhancement, riparian management, and barrier removal, may be able to recover a substantial amount of brook trout habitat lost to historic landscape change. However, restoration efforts must be designed within the context of expected impacts from climate change or those efforts may not produce long‐term benefits to brook trout in this region. [ABSTRACT FROM AUTHOR]

We provide an assessment of thermal characteristics and climate change vulnerability for brook trout ( Salvelinus fontinalis ) habitats in the upper Shavers Fork sub-watershed, West Virginia. Spatial and temporal (2001–2015) variability in observed summer (6/1–8/31) stream temperatures was quantified in 23 (9 tributary, 14 main-stem) reaches. We developed a mixed effects model to predict site-specific mean daily stream temperature from air temperature and discharge and coupled this model with a hydrologic model to predict future (2016–2100) changes in stream temperature under low (RCP 4.5) and high (RCP 8.5) emissions scenarios. Observed mean daily stream temperature exceeded the 21 °C brook trout physiological threshold in all but one main-stem site, and 3 sites exceeded proposed thermal limits for either 63- and 7-day mean stream temperature. We modeled mean daily stream temperature with a high degree of certainty ( R 2 = 0.93; RMSE = 0.76 °C). Predicted increases in mean daily stream temperature in main-stem and tributary reaches ranged from 0.2 °C (RCP 4.5) to 1.2 °C (RCP 8.5). Between 2091 and 2100, the average number of days with mean daily stream temperature > 21 °C increased within main-stem sites under the RCP 4.5 (0–1.2 days) and 8.5 (0 − 13) scenarios; however, no site is expected to exceed 63- or 7-day thermal limits. During the warmest 10 years, ≥ 5 main-stem sites exceeded the 63- or 7-day thermal tolerance limits under both climate emissions scenarios. Years with the greatest increases in stream temperature were characterized by low mean daily discharge. Main-stem reaches below major tributaries never exceed thermal limits, despite neighboring reaches having among the highest observed and predicted stream temperatures. Persistence of thermal refugia within upper Shavers Fork would enable persistence of metapopulation structure and life history processes. However, this will only be possible if projected increases in discharge are realized and offset expected increases in air temperature. [ABSTRACT FROM AUTHOR]

There is a critical need for tools and methodologies capable of managing aquatic systems within heavily impacted watersheds. Current efforts often fall short as a result of an inability to quantify and predict complex cumulative effects of current and future land use scenarios at relevant spatial scales. The goal of this manuscript is to provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework. Sites are first selected for inclusion within the watershed assessment by identifying sites that fall along independent gradients and combinations of known stressors. Field and laboratory techniques are then used to obtain data on the physical, chemical, and biological effects of multiple land use activities. Multiple linear regression analysis is then used to produce landscape-based cumulative effects models for predicting aquatic conditions. Lastly, methods for incorporating cumulative effects models within a scenario analysis framework for guiding management and regulatory decisions (e.g., permitting and mitigation) within actively developing watersheds are discussed and demonstrated for 2 sub-watersheds within the mountaintop mining region of central Appalachia. The watershed assessment and management approach provided herein enables resource managers to facilitate economic and development activity while protecting aquatic resources and producing opportunity for net ecological benefits through targeted remediation.