Strong variation in Brook Trout trends across geology, elevation, and stream size in Shenandoah National Park

Transactions of the American Fisheries Society, Journal Year: 2024, Volume and Issue: 153(2), P. 250 - 263

Published: Feb. 22, 2024

Abstract Objective Landscape context structures fish abundance and dynamics, understanding trends in across the landscape is often prerequisite for effective conservation. In this study, we evaluated status of Brook Trout Salvelinus fontinalis Shenandoah National Park to understand how these are structured bedrock geology, elevation, stream size. Methods We used long‐term monitoring data from 94 sites evaluate over a 27‐year period (1996–2022) assess importance local environmental covariates using hierarchical Bayesian N‐mixture model based on depletion sampling. Focal were chosen their demonstrated structuring populations elsewhere. Bedrock geology controls sensitivity acid deposition, watershed area related habitat features such as complexity flow variability, elevation creates gradients temperature. Result Models revealed significant decreases adult time (95% credible intervals < 0) 31 (33%), at least three exhibited apparent extirpations study period. Estimated declined by 50% or more approximately 70% streams park Sites with warmest water temperatures fastest declines abundance. However, large watersheds poorly buffered gains time, suggesting some recovery deposition due improvements air quality. Conclusion Our analysis divergent changes recent decades suggests temperature probable causal mechanisms. These results highlight considering factors when evaluating populations. Results can assist development targeted conservation actions within

Language: Английский

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Taking heat (downstream): Simulating groundwater and thermal equilibrium controls on annual paired air–water temperature signal transport in headwater streams

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 638, P. 131391 - 131391

Published: May 23, 2024

Language: Английский

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Diel temperature signals track seasonal shifts in localized groundwater contributions to headwater streamflow generation at network scale

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 639, P. 131528 - 131528

Published: June 16, 2024

Groundwater contributions to streamflow sustain aquatic ecosystem resilience; streams without significant groundwater inputs often have well-coupled air and water temperatures that degrade cold-water habitat during warm low flow periods. Widespread uncertainty in stream-groundwater connectivity across space time has created disparate predictions of energy nutrient fluxes headwater networks, hindering resilience under climate change scenarios. Recently, annual paired temperature signals been harnessed indicate stream thermal sensitivity the dominance deep versus shallow influence, although utility diel air–water signal metrics for hydrologic inference remained unexplored. Here we analyzed two consecutive years locally paired, data from 47 sites Catskill Mountains, New York, USA, discovered characteristic seasonal patterns sinusoid (amplitude ratio, phase lag, mean ratio) driven by shifts generation mechanisms network position. Hydrologic interpretations observed were supported heat budget model scenarios additional analysis Shenandoah National Park, Virginia, with well characterized connectivity. We found within smaller tributaries, transitions runoff hillslope drying periods lower precipitation. This was evidenced correlations (p < 0.01) between daily water:air amplitudes (non-linear decreases ∼ 50 %) derived base-flow index at 22 28 sites, indicating enhanced local influence on promotes decoupling signals. Additionally, ratios means tributaries (∼0.68) when compared main-stem (∼0.8) increasing linearly throughout observational period. In conceptual models, inflow had minimal effects lags (∼0.2 hr), but increases fractional discharge (0–50 depressed amplitude (∼20 % (∼15 %), supporting interpreted changes streamflow. During (i.e., April through October 2021 2022), differences tributary occurred highest (∼0.93 vs. 0.68), as dominated channel inertia, rather than connectivity, showing coupling warmer, drier Divergent being distance source zones, lateral inflows do not contribute a meaningful fraction network. Given growing footprint observations, can provide distributed sensitive upstream discharge. Consequently, these support ongoing efforts resource managers researchers seeking forecast warming changing precipitation regimes mountain streams.

Language: Английский

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Stream groundwater inputs generate fine‐scale variation in brook trout phenology and growth across a warming landscape

Freshwater Biology, Journal Year: 2023, Volume and Issue: 69(1), P. 127 - 142

Published: Nov. 10, 2023

Abstract Climate change is increasing global atmospheric temperatures, which can reduce abundance and cause range shifts in species that are sensitive to warming. However, fine‐scale thermal heterogeneity drive highly variable local responses climate change, especially freshwater environments differ groundwater inputs geomorphology. We used temperature data collected during 2012–2021 from 10 small, pristine streams eastern Canada characterise variation at a small spatial scale (~25 km 2 ). then relationships between daily air stream temperatures reconstruct since 1980, assessed how influenced the phenology growth of brook trout ( Salvelinus fontinalis Air–stream varied considerably among despite their close proximity, with predicted summer differing up 9.5°C warmer rainfall‐dominated cooler groundwater‐dominated streams. Rainfall‐dominated warmed more than twice as fast across all seasons nearly four‐fold differences rates warming evident months. Fine‐scale also shaped phenology, juveniles were estimated hatch emerge much later (~70 40 days, respectively) experience faster phenological Relationships juvenile size accumulated degree‐days positive, but slopes differed over two‐fold did not vary systematically based on hydrology, suggesting idiosyncratic impacts early growth. Collectively, our study illustrates be consistent direction substantially magnitude owing influence groundwater. Future likely increase stress experienced by populations streams, while potentially benefiting those where current often suboptimal. Observed ecological suggest must considered when forecasting effects future fish population dynamics.

Language: Английский

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Karst Terrain Promotes Thermal Resiliency in Headwater Streams

Proceedings of the West Virginia Academy of Science, Journal Year: 2023, Volume and Issue: 95(3)

Published: April 19, 2023

The response of stream ecosystems to climate change will depend in part on groundwater processes that reduce the sensitivity streams atmospheric conditions. We investigated thermal across a gradient inputs defined by karst terrain (carbonate parent materials) headwaters Potomac River basin eastern North America. collected temperature data and quantified for 30 sites from relationship between daily mean water air temperatures. Our analysis demonstrates is lower than elsewhere, effect more important effects elevation or size this regard. study indicates importance karstic resiliency suggests riparian vegetation maintaining temperatures elsewhere. also provides simple rapid method research can be implemented conjunction with watershed organizations citizen science networks.

Language: Английский

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Groundwater Springs Influence Fish Community Distribution and Trout Condition across a Longitudinal Gradient in a Coldwater Catchment in Southeastern MN, USA

Published: June 24, 2024

The thermal conditions of transitional (ranging from warm to cold) coldwater streams impact the ranges and resource availabilities for biota inhabiting these lotic systems. With ongoing climate change increasing land modifications, boundaries may shift, altering transition zones their biotic communities. objective this study was investigate condition trout across three forks Whitewater River catchment factors influencing fish community composition distribution. Each fork characterized into separate sections: headwater (coolwater), middle (warmwater), lower (coldwater). Springs were identified throughout each fork, with greatest concentrations in sections fork. Using single-pass electrofishing, we sampled 61 sites system (North = 21 sites, Middle 19, South 21), catch statistics used calculate diversity, abundance, condition. In general, diversity increased, healthier but less abundant sections, whereas decreased slightly, decreased, abundance increased reaches, changes differing somewhat among forks. Canonical correlation analysis had strong significant correlations showing simpson increase going upstream high non rates while reach width decrease. is a exhibiting temperature-pattern characteristics generally low that range thin, normal, robust. Dominated by changing landscape (agriculture) intensifying change, begin see stream temperatures along species diversity. Understanding how spring temperature influences distribution can bring potential stressors light our understanding help mitigate negative impacts use change.

Language: Английский

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Groundwater Springs Influence Fish Community Distribution and Trout Condition across a Longitudinal Gradient in a Coldwater Catchment in Southeastern Minnesota, USA

Water, Journal Year: 2024, Volume and Issue: 16(14), P. 1961 - 1961

Published: July 11, 2024

The thermal conditions of transitional (ranging from warm to cold) coldwater streams impact the ranges and resource availabilities for biota inhabiting these lotic systems. With ongoing climate change increasing land modifications, boundaries may shift, altering transition zones their biotic communities. objective this study was investigate condition trout across three forks Whitewater River catchment, located in southeastern Minnesota, factors influencing fish community composition distribution. Each fork characterized into separate sections: headwater (coolwater), middle (warmwater), lower (coldwater). Springs were identified throughout each fork, with greatest concentrations sections fork. Using single-pass electrofishing, we sampled 61 sites system (North = 21 sites, Middle 19, South 21), catch statistics used calculate diversity, abundance, condition. In general, diversity increased, healthier but less abundant sections, whereas decreased slightly, decreased, abundance increased reaches, changes differing somewhat among forks. Canonical correlation analysis highlighted strong significant correlations showing that Simpson increase going upstream, high non-trout while rates decrease width narrows. is a catchment exhibiting temperature-pattern characteristics generally low range thin, normal, robust. Dominated by changing landscape (agriculture) intensifying change, begin see stream temperatures along species diversity. Understanding how spring temperature influences distribution can bring potential stressors light, our understanding helping mitigate negative impacts use change.

Language: Английский

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Declines in Brook Trout Abundance Linked to Atmospheric Warming in Maryland, USA

Hydrobiology, Journal Year: 2024, Volume and Issue: 3(4), P. 310 - 324

Published: Oct. 1, 2024

Salmonid fishes provide an important indicator of climate change given their reliance on cold water. We evaluated temporal changes in the density stream-dwelling brook trout (Salvelinus fontinalis) from surveys conducted over a 36-year period (1988–2023) by Maryland Department Natural Resources Eastern North America. Nonparametric trend analyses revealed decreasing densities adult fish (age 1+) 19 sites (27%) and increases 5 (7%). In contrast, juvenile 0) decreased 4 (6%) increased 10 (14%). Declining trends were related to atmospheric warming rates during study period, this relationship was stronger than effects land use or non-native brown trout. generally with elevation but not air temperature change. Our analysis reveals significant several populations recent decades implicates conditions population declines. findings also suggest importance for survival rather recruitment limitation dynamics.

Language: Английский

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