Global consequences of dam‐induced river fragmentation on diadromous migrants: a systematic review and meta‐analysis

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 7, 2025

ABSTRACT The global proliferation of dams has altered flow and sediment regimes in rivers, presenting a major threat to freshwater biodiversity. Diadromous species, such as fishes, decapod crustaceans gastropods, are particularly susceptible fragmentation because obstruct their breeding migrations between coastal waters rivers. Although have contributed significant declines abundance some commercially important diadromous fishes (salmonids anguillids) Macrobrachium shrimps, understanding the impacts on majority animals is limited. Moreover, number species known life cycles risen substantially during last four decades, from ~250 more than 800. This synthesis aims consolidate highlight potential knowledge gaps. We identified 338 publications documenting decapods, but this was reduced 65 after application our strict selection criteria. Specifically, we only included studies that compared unfragmented (e.g. undammed) or restored with fish passes) fragmented site above dams) To assess statistical significance, results were replicated sufficiently enable calculation standardised effect sizes also subject meta‐analysis focusing three topics: dam‐induced fragmentation; efficacy passes; mitigative dam removal. Study outcomes evaluated five key variables: abundance; richness; assemblage composition; population genetic diversity; structure. found led net negative effects across all variables for fishes. Fishes limited jumping climbing ability obligate migrants cannot persist landlocked populations threatened by fragmentation. However, capable climbers jumpers facultatively nonetheless impacts, gene populations. Installation passes did not lead positive outcomes, whereas removal effective restoring connectivity suggesting it effective, albeit potentially contentious, approach may serve an societal need), habitat connectivity. A smaller investigated decapods (seven versus 61 fishes), findings suggests vulnerable alteration dams, less sensitive barrier they better Gastropods least studied taxon, none met criteria systematic review meta‐analysis. imbalance information about taxa compounded scarcity tropics, South America, Africa, Asia, Southeast East Asia. These regions support diverse aquatic assemblages so be underestimated given existing conservation would best served avoiding construction while improving mitigation strategies, passage design, limit most damaging river

Language: Английский

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Widespread Deviant Patterns of Heterozygosity in Whole-Genome Sequencing Due to Autopolyploidy, Repeated Elements, and Duplication

Genome Biology and Evolution, Journal Year: 2023, Volume and Issue: 15(12)

Published: Dec. 1, 2023

Abstract Most population genomic tools rely on accurate single nucleotide polymorphism (SNP) calling and filtering to meet their underlying assumptions. However, complexity, resulting from structural variants, paralogous sequences, repetitive elements, presents significant challenges in assembling contiguous reference genomes. Consequently, short-read resequencing studies can encounter mismapping issues, leading SNPs that deviate Mendelian expected patterns of heterozygosity allelic ratio. In this study, we employed the ngsParalog software identify such deviant whole-genome sequencing (WGS) data with low (1.5×) intermediate (4.8×) coverage for four species: Arctic Char (Salvelinus alpinus), Lake Whitefish (Coregonus clupeaformis), Atlantic Salmon (Salmo salar), American Eel (Anguilla rostrata). The analyses revealed accounted 22% 62% all salmonid datasets approximately 11% dataset. These were particularly concentrated within elements regions had recently undergone rediploidization salmonids. Additionally, narrow peaks elevated ubiquitous along genomes, encompassed most SNPs, could be partially associated transposons tandem repeats. Including these led highly distorted site frequency spectra, underestimated pairwise FST values, overestimated diversity. Considering widespread occurrence arising a variety sources, important impact estimating parameters, availability effective them, propose excluding WGS is required improve inferences wide range taxa depths.

Language: Английский

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Living in a post‐industrial landscape: repeated patterns of genetic divergence in brown trout (Salmo trutta L.) across the British Isles

Diversity and Distributions, Journal Year: 2024, Volume and Issue: 30(7)

Published: May 31, 2024

Abstract Aim The British Isles have been worked for millennia to extract metal ores feed industrial development, leaving a legacy of mine water pollution that continues impact freshwater communities in many regions. Brown trout ( Salmo trutta L.) long observed persist these metal‐impacted systems as apex predators, with previous studies showing small number impacted populations be highly genetically divergent. We sought understand the scale genetic diversity across regions and repeatability divergence affected by pollution. Location examined four water‐impacted Isles: west Wales, northeast England, southwest England southeast Ireland. Methods employed panel 95 SNP loci screen 1236 individuals from 71 sites representing paired clean From these, we obtained statistics, assessed structuring modelled historical demographic scenarios which factors most credibly explain variation divergent populations. Results evidenced hierarchical population structure studied, line expectations phylogeographic history. However, analysis first level differentiation was driven Cornwall England. Within reduced repeated patterns local sub‐structuring between samples relatively sites. Demographic history analyses suggested timing splits recent associated periods peak mining activity. Main conclusions Our findings demonstrate distinct isolation arising ecosystems, impacts being apparent where both chemical physical barriers are present. Management should focus on amelioration wash‐out removal fish movement safeguard

Language: Английский

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Dam removal enables diverse juvenile life histories to emerge in threatened salmonids repopulating a heterogeneous landscape

Frontiers in Ecology and Evolution, Journal Year: 2023, Volume and Issue: 11

Published: June 2, 2023

Human stressors block, eliminate, and simplify habitat mosaics, eroding landscapes’ life history diversity thus biological resilience. One goal of restoration is to alleviate human that suppress diversity, but responses these efforts are still coming into focus. Here, we report emerging in threatened salmonids ( Oncorhynchus spp.) repopulating the recently undammed Elwha River (WA, United States) adjacent environmentally distinct tributaries. The ~20 km tributaries entered <1 apart, one had a colder stream temperature regime swifter waters due its high, snow-dominated elevation steep valley gradient (~3%), while other warmer slower because it drained lake, was at lower elevation, (~1.5%). Following 2012 removal Dam, tributaries’ generally became more abundant expressed diverse histories within among species. warmer, low-gradient tributary produced age-1+ coho salmon colder, steeper notably high abundance steelhead smolts 2020. Additionally, exiting were older possibly larger for their age class, emigrated ~25 days earlier, included age-0 Chinook larger. Also, assemblage composition varied years, with most species shifting between salmon, abundances increased patchy. These patterns consistent newly accessible, heterogeneous landscape generating against backdrop patchy recruitment as salmonids—some considerable hatchery-origin ancestry—repopulate an extirpated landscape. Overall, dam appears have promoted which may bolster resilience during era rapid environmental change portend positive outcomes upcoming removals similar goals.

Language: Английский

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Seven dam challenges for migratory fish: insights from the Penobscot River

Frontiers in Ecology and Evolution, Journal Year: 2023, Volume and Issue: 11

Published: Oct. 16, 2023

More than a century of impoundments in the Penobscot River, Maine, USA, has contributed to population declines migratory fish system. A decade change, research, and monitoring revealed direct indirect ways that dams have influenced river habitat, connectivity for fish, food web. The removal two main-stem (in 2012 2013) bolstering passage been part coordinated restoration efforts watershed. Integral this undertaking was support short- long-term research included physical passage, broad scale ecological assessments. Herein we discuss seven interconnected complex affected River ecosystem, particularly fish. These include familiar influences ascribed dams: i) impaired access ii) injury mortality, iii) delays migration. Other are less studied more subtle: iv) facilitation predation, v) community shifts, vi) demographic shifts. Lastly, result vii) loss ecosystem services would otherwise be intact an unimpounded We draw on both examples from broader information characterize how transformed century. Recent dam removals mitigation reestablished some these functions.

Language: Английский

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Initial responses of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) to removal of two dams on the Elwha River, Washington State, U.S.A.

Frontiers in Ecology and Evolution, Journal Year: 2024, Volume and Issue: 12

Published: July 17, 2024

Large dam removal is being used to restore river systems, but questions remain regarding their outcomes. We examine how the of two large dams in Elwha River, coupled with hatchery production and fishing closures, affected population attributes Chinook salmon ( Oncorhynchus tshawytscha ) steelhead O. mykiss ). Initial responses by returning adult was an increase number spatial extent natural origin fish. Although few naturally produced juvenile outmigrants were observed prior during removal, abundances increased three years after fish passage restored, suggesting that impacts due downstream sedimentation reduced. The demographics dominated production, while increases winter abundance included both natural-origin spawners. expansion upstream former sites predominantly also a “reawakening” summer part derived from up-river resident returned Upper Elwha. Our results showed combination habitat, hatchery, harvest actions can result positive for salmonid populations.

Language: Английский

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Spatial–temporal patterns of fish trophic guilds in a freshwater river wetland ecosystem of northeastern China

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(7)

Published: July 1, 2024

Abstract Muling River, situated amidst cultivated lands in Heilongjiang Province, northeastern China, has long been subjected to sand‐digging activities, resulting severe damage its riverbed. However, little research conducted on the impact of this disturbance status fish community structure and trophic guilds river. In study, environmental factors, structure, guild biomass distribution patterns from River basin were investigated among seasons (spring, summer, autumn) sections (upper, middle, lower stream) 2015 2017. During six sampling times periods, 46 species five orders 12 families classified into seven guilds. Fish number higher upper reaches watershed. The insectivores (16.26%), phytoplanktivores (10.09%), benthivores (40.17%), omnivores (11.86%) dominant We found that factors such as transparency, water depth, pH value, total phosphorus, chemical oxygen demand highest section compared other sections. Variation partitioning revealed was influenced more by (61.2%), followed (0.7%) season (0.1%). Partial RDA ordination showed positively correlated with depth while negative turbidity. This study underscores importance considering freshwater fishes inform management strategies regions experiencing significant change.

Language: Английский

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Genetic variation associated with adult migration timing in lineages of Steelhead and Chinook Salmon in the Columbia River

Evolutionary Applications, Journal Year: 2023, Volume and Issue: 17(2)

Published: Dec. 28, 2023

Abstract With the discovery of a major effect region (GREB1L, ROCK1) for adult migration timing in genomes both Chinook Salmon and Steelhead, several subsequent studies have investigated size distribution early late alleles among populations Columbia River. Here, we synthesize results these lineages Steelhead that include highly distinct groups interior River exhibit atypical life histories from most coastal lineage two species. Whole‐genome with high marker density provided extensive insight into SNPs associated timing, suites markers each species been genotyped large numbers individuals to further validate phenotypic effects. For largest sizes observed (36% variation passage at Bonneville Dam; 43% tributary arrival timing) compared inland (7.5% 8.4% overwinter freshwater prior spawning. Salmon, all three multiple phenotypes (Coastal lineage: percentage 27.9% Dam, 28.7% spawning; Interior ocean type: 47.6% 39.6% 77.9% stream 35.3% 9.8% 4.7% spawning). Together, extended our understanding genetic history diversity River, however, much research remains necessary determine causal mechanism this on

Language: Английский

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Dam Removal and River Restoration

Elsevier eBooks, Journal Year: 2021, Volume and Issue: unknown, P. 576 - 585

Published: Dec. 9, 2021

Language: Английский

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Widespread deviant patterns of heterozygosity in whole-genome sequencing due to autopolyploidy, repeated elements, and duplication

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: July 30, 2023

Abstract Most population genomic tools rely on accurate SNP calling and filtering to meet their underlying assumptions. However, complexity, due structural variants, paralogous sequences repetitive elements, presents significant challenges in assembling contiguous reference genomes. Consequently, short-read resequencing studies can encounter mismapping issues, leading SNPs that deviate from Mendelian expected patterns of heterozygosity allelic ratio. In this study, we employed the ngsParalog software identify such deviant whole-genome sequencing data four species: Arctic Char ( Salvelinus alpinus ), Lake Whitefish Coregonus clupeaformis Atlantic Salmon Salmo salar American Eel Anguilla rostrata with low (2X) intermediate (6X) coverage. The analyses revealed accounted for up 62% all salmonid datasets approximately 10% dataset. These were particularly concentrated within elements regions had recently undergone rediploidization salmonids. Additionally, narrow peaks elevated coverage ubiquitous along genomes, encompassed most could be partially attributed transposons tandem repeats. Including these led highly distorted site frequency spectra, apparent homogenization populations underestimating pairwise F ST values. Considering widespread occurrence arising a variety source, important impact estimating parameters, availability effective them, propose excluding deviant-SNPs WGS is required improve inferences wide range taxa depths. Significance: Genomes very hard assemble into reference, which lead biases when genotyping genetic markers complex regions. Here, draw attention issue various validate method problematic at We also explore processes creating consequences common genomics analyses.

Language: Английский

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