Ecology of Freshwater Fish最新文献

{"title":"Movement Behaviour of Three Rheophilic Cyprinids in a Culvert-Fragmented Stream","authors":"Nele K. Borowski,&nbsp;Pim Lemmers,&nbsp;Joris J. F. Verhees,&nbsp;Ben H. J. M. Crombaghs,&nbsp;Didier J. R. C. Lemmens,&nbsp;Wim J. A. M. Lemmers,&nbsp;Casper H. A. van Leeuwen","doi":"10.1111/eff.70066","DOIUrl":"https://doi.org/10.1111/eff.70066","url":null,"abstract":"<p>Many freshwater fish species rely on movement across unobstructed river systems to complete their life cycles. However, anthropogenic activities such as river regulation, dams, and culverts increasingly restrict fish movements by compromising river connectivity and altering habitat characteristics. This study aimed to assess the effect of habitat modification and a 76 m long culvert on the movement of three rheophilic cyprinids (common barbel <i>Barbus barbus</i>, European chub <i>Squalius cephalus</i>, and common nase <i>Chondrostoma nasus</i>) in the River Geul, a chalk stream in the Netherlands. We hypothesised that (1) most habitat use would be observed upstream of the culvert, (2) interspecific variation in culvert passage rates would be present because of differences in movement timing throughout the diurnal cycle, where least effects of culvert fragmentation were expected on more nocturnally active species such as the common barbel, and (3) the culvert would affect larger, adult individuals the least, due to their increased swimming capabilities and larger home ranges. Radio-frequency identification (RFID) telemetry data obtained with passive integrated transponders (PIT tags) revealed significant discrepancies in habitat use among river sections, where all three species occurred most in the more natural, upstream sections of the river. Passage rates of the culvert were high, and passage did not differ between species with varying diel timing of movement. However, larger individuals that had been tagged for a longer time were generally more likely to pass through the culvert. We conclude that habitat modifications and the construction of migration barriers resulted in the increased occurrence of three rheophilic cyprinid species in the more upstream, natural sections of a chalk stream, and that these anthropogenic activities therefore likely restrict the extent of available suitable habitat.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"36 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149219502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Present and Future Thermal–Oxygen Habitat for Glacial-Relict Fish at Southern Range Margins","authors":"Antony Smith,&nbsp;Gary Carvalho,&nbsp;Nigel Milner,&nbsp;Alexander S. T. Papadopulos,&nbsp;Mathew Seymour","doi":"10.1111/eff.70070","DOIUrl":"https://doi.org/10.1111/eff.70070","url":null,"abstract":"<p>Climate change and eutrophication may alter the distribution of species through their effects on freshwater thermal–oxygen regimes. We quantified the deep-water thermal–oxygen niche of cold-adapted glacial-relict fish (<i>Salvelinus alpinus</i> and <i>Coregonus</i> spp.) at the southern range to assess their vulnerability to a changing environment. Using data from 104 lakes across the UK and Ireland, we developed a logistic regression model that identified temperature in summer at the 7 mg L⁻¹ oxygen isoline (TDO7) as a significant predictor of species presence. The model pooling <i>S. alpinus</i> and <i>Coregonus</i> species presence–absence estimated a TDO7 central niche of &lt; 11.5°C (CI 10.9°C–12.1°C) and an upper niche of 17.5°C (CI 16.2°C–19.2°C), whereas the model for <i>S. alpinus</i> alone estimated central and upper thresholds of &lt; 10.7°C (CI 10.2°C–11.5°C) and 16.6°C (CI 15.2°C–18.3°C), respectively. Under a worst-case climate scenario for 2061–2080, modelled TDO7 across 29 lakes supporting cold-adapted fish increased by an average of 3.25°C in response to a projected 3.43°C average rise in maximum air temperature. Under these conditions, 56% of lakes were predicted to remain below the upper niche range; however, none remained within the central niche. Lake maximum depth was the strongest predictor of TDO7, and future TDO7 remained below the upper niche range only in stratified lakes with a maximum depth &gt; 27.4 m and spring total phosphorus &lt; 19.1 μg L⁻¹. Deep, stratified, oligo-mesotrophic lakes therefore represent critical climate refugia, highlighting the importance of protecting these systems from non-climatic stressors to maximise species persistence under climate warming.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"36 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70070","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149219508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ontogenetic Niche Shifts and Life-History Variation Shape Mercury Accumulation in European Perch","authors":"Eirik H. Henriksen,&nbsp;Julie Fredriksen,&nbsp;Amanda E. Poste,&nbsp;Maeve McGovern,&nbsp;Michael Power,&nbsp;Guttorm N. Christensen,&nbsp;Per-Arne Amundsen","doi":"10.1111/eff.70065","DOIUrl":"https://doi.org/10.1111/eff.70065","url":null,"abstract":"<div>\u0000 \u0000 <p>Mercury (Hg) bioaccumulates in aquatic organisms and biomagnifies through food webs, potentially reaching concentrations that affect fish, wildlife and human health. Because Hg concentrations generally increase with trophic position, ontogenetic shifts towards piscivory can increase dietary Hg exposure as fish begin consuming prey with higher Hg concentrations than lower-trophic invertebrates. Here, we investigated drivers of Hg accumulation in European perch (<i>Perca fluviatilis</i>) from two subarctic lakes by combining stomach-content data, carbon and nitrogen stable isotopes, and total mercury (THg) concentrations. Fish length and trophic position (indicated by δ¹⁵N) were the strongest predictors of THg concentrations, and length-based models performed substantially better than age-based models. Increasing fish size was accompanied by an ontogenetic dietary shift from predominantly invertebrate prey towards piscivory. Mean THg concentrations were higher and the relationship between THg and δ¹⁵N was steeper in lake Skrukkebukta than in lake Vaggatem. Males had higher THg concentrations than females after accounting for other predictors, while body condition was negatively associated with THg. Overall, our results indicate that ontogenetic changes in trophic ecology are important drivers of Hg accumulation in perch, while sex, body condition and lake-specific conditions contribute additional variation. The findings highlight the importance of considering species-specific trophic ecology and life-history variation, particularly differences in somatic growth, when assessing Hg dynamics and fish-consumption risks in freshwater ecosystems.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"36 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149219512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predation Risk and Depth Use During Migration of Atlantic Salmon Smolts Through a Fjord Impacted by Hydropower Discharge","authors":"Robert J. Lennox,&nbsp;Knut Wiik Vollset,&nbsp;Saron Berhe,&nbsp;Tormod Haraldstad","doi":"10.1111/eff.70062","DOIUrl":"https://doi.org/10.1111/eff.70062","url":null,"abstract":"<p>Atlantic salmon (<i>Salmo</i> must survive the transition from river to fjord in order to migrate to northern latitudes where they feed and grow at sea. In the River Suldalslågen in southern Norway, hydropower regulated water discharge determines the timing and extent of river flows and fjord currents. To better understand how hydropower discharge influences smolt migration, we investigated early marine migration using acoustic telemetry and sensor tags in the fjord during 2 years. Smolts were tagged from the wild and a hatchery facility in 2023 and from the wild in 2024 using ID tags, depth sensor tags, and predation sensor tags and released in the river or towed to the fjord. Once smolts entered the fjord, they moved out to sea relatively quickly, and the route selected was influenced by the river flow from River Suldalslågen such that the northern route was infrequently used during periods of low river flow. Mortalities were concentrated near the river mouth and at one physical bottleneck in the fjord, which coincided with a bridge constructed over the fjord. Predation sensors helped resolve that a share of this mortality was attributable to aquatic predators, likely brown trout (<i>Salmo</i> and a mix of other marine teleosts. Smolts navigated the fjord mostly close to the water surface, with minimal spatial variation in depth use but some clear diel patterns of moving deeper during daytime. Hydropower regulators should consider how artificial freshets in rivers influence downstream behaviour of the smolts even after exiting the river to the fjord.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scale Dependent Temporal and Spatial Patterns of Population Change in Anadromous Sea Trout (Salmo trutta) in Scotland Over Seven Decades","authors":"J. A. Dodd,&nbsp;I. E. Moore,&nbsp;Adrian W. Bowman,&nbsp;C. W. Bean,&nbsp;J. R. Rodger,&nbsp;C. E. Adams","doi":"10.1111/eff.70064","DOIUrl":"https://doi.org/10.1111/eff.70064","url":null,"abstract":"<p>The spatial scale at which temporal change in a population is measured has the potential to skew the inferences drawn on patterns of change from monitoring data. This study analysed data from rod catches of anadromous sea trout (<i>Salmo trutta</i>) in Scotland over 72 years and three spatial scales (National, Regional and District). The pattern of temporal change evident at the national scale mostly did not clearly manifest at Regional or at District spatial scales, which were also generally decoupled. At the National level, very clear and substantive declines were evident. At Regional levels (<i>N</i> = 9) change was more nuanced, with some Regions showing no change, one Region showing an increase in catch, and 6 (67%) exhibited a different pattern from the National one. At the District levels (<i>N</i> = 64) opposing patterns of change were observed, even in adjacent Districts, with 80% exhibiting a different pattern from the National one. We conclude that, as a national resource, sea trout numbers have declined substantively over the last seven decades (by around 50%). However, this general picture is not applicable at Regional nor District level. The lack of correlation in response amongst small spatial scales indicates a Portfolio Effect indicating that the observed national pattern of change represents the combination of more variable trends at smaller spatial scales. Two other logical inferences derive from these results. First, for best effect, the application of limited resources for management should focus on smaller scales. Second, that monitoring population change at small spatial scales alone, for example in several index rivers, is unlikely to capture the nuanced patterns of change in species with high levels of intra-specific structuring as is found in the Salmonidae.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Temperature, Flow, Density and Disease on Smallmouth Bass (Micropterus dolomieu) Early Life Growth Rate","authors":"Rebecca S. M. O'Brien,&nbsp;Megan K. Schall,&nbsp;Geoffrey D. Smith,&nbsp;Kelly L. Smalling,&nbsp;Tyler Wagner","doi":"10.1111/eff.70063","DOIUrl":"https://doi.org/10.1111/eff.70063","url":null,"abstract":"<p>Individual growth rates of fish are influenced by gradually changing environmental conditions and rapid-onset events. However, there is a paucity of information on drivers of spatiotemporal variability in growth rates of fishes across large spatial extents. Using a 36-year dataset of smallmouth bass (<i>Micropterus dolomieu</i>) length-at-age data across 10 river reaches in Pennsylvania, USA (<i>n</i> = 54,068 individuals), we estimated annual early life growth rates (mm year⁻¹) and assessed the effects of relative abundance, summer temperature, summer streamflow rate and a disease outbreak on growth rate. We found that temperature had a positive effect on growth rate, varied spatially, and had a stronger effect in diseased reaches. There was also evidence for an impact of disease on early life growth through density-dependent mechanisms, with growth rates increasing from ∼85 to 101 mm·year⁻¹ following disease-related decreases in abundance. This study adds to our understanding of the factors that shape early life growth, including rapid-onset events like disease which can have immediate and lasting effects on growth rate trajectory.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating Acoustic Telemetry and Stable Isotope Data Reveals Overlap in Resource Use by Large-Bodied Fishes in a Temperate Lake","authors":"Ian A. Richter,&nbsp;Alyssa M. Andersen,&nbsp;Karen E. Smokorowski,&nbsp;Paul J. Blanchfield","doi":"10.1111/eff.70057","DOIUrl":"https://doi.org/10.1111/eff.70057","url":null,"abstract":"<p>Temperate lake ecosystems undergo seasonal shifts that disproportionately alter the availability of suitable habitat for fishes of different thermal guilds. While many studies have investigated fish habitat use patterns, few have estimated the degree to which fish species overlap in space across seasons from a three-dimensional perspective. Here, we investigated the seasonal timing of habitat overlap and trophic niches of key fish species—burbot (<i>Lota lota</i>), lake trout (<i>Salvelinus namaycush</i>) and white sucker (<i>Catostomus commersonii</i>)—in a small boreal lake located in Ontario, Canada. Using a spatial telemetry array and pressure-sensing transmitters, we collected 2 years of three-dimensional fish habitat use data, which we paired with stable isotope data (carbon, nitrogen and sulphur) from all trophic levels to distinguish littoral (nearshore), pelagic (offshore) and benthic sources of energy acquisition. Telemetry data analysis showed that three-dimensional space use and habitat overlap significantly differed across species and were season-specific, particularly between burbot and lake trout. Stable isotope analysis demonstrated a high reliance upon littoral resources for the three fish species, which generally matched telemetry estimates of nearshore habitat use, apart from the unexpectedly high littoral signature for burbot. Our joint application of acoustic telemetry and stable isotope analysis provided a deeper insight into the spatial and trophic ecology of these important fish species, clarifying how species with seasonal spatial overlap can thrive by relying on different food resources.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fragmentation by Dams and Habitat Quality Affect Body Condition of a Small Characid in a Neotropical System","authors":"Ana Carolina Daldegan,&nbsp;Yan F. F. Soares,&nbsp;Paulo Vitor Rabelo,&nbsp;Vinicius Urbano,&nbsp;Bruno E. Soares,&nbsp;Juan P. Quimbayo,&nbsp;Laura B. Paula-Souza,&nbsp;Carmino Emidio Junior,&nbsp;Amanda S. Vasconcelos,&nbsp;Débora L. Ferreira,&nbsp;Veronica Slobodian,&nbsp;Eduardo Bessa,&nbsp;Murilo S. Dias","doi":"10.1111/eff.70059","DOIUrl":"https://doi.org/10.1111/eff.70059","url":null,"abstract":"<p>The structure of stream networks naturally fragments freshwater habitats, but this complexity is increasingly intensified by dams and reservoirs. How anthropogenic fragmentation interacts with natural isolation gradients to affect fish populations remains poorly understood. Here, we tested how natural (position within the river network, i.e., closeness centrality, and elevation) and anthropogenic (cumulative reservoir volume) isolation gradients influenced body condition of <i>Psalidodon</i> aff. <i>fasciatus</i> across stream reaches distributed in two sub-basins upstream of Lake Paranoá, Upper Paraná River basin, Brazil. We estimated body condition as residual mass from the length–weight relationship using generalized linear mixed-effects models, testing effects of isolation predictors and local environmental variables simultaneously. Populations exhibited positive allometric growth, contrasting with typical reports for the species. Contrary to our hypothesis, body mass was significantly higher at sites with greater cumulative reservoir volume downstream. Individuals from the right sub-basin exhibited greater body mass than those from the left sub-basin. Natural isolation predictors (closeness centrality and elevation) had no significant effect. Body mass was significantly positively related to water temperature and negatively related to substrate diversity. Our results suggest that body mass varied in response to environmental conditions and the presence of dams, which may benefit this generalist species by expanding foraging habitats and resource availability. These findings highlight that the impacts of fragmentation are species-specific: while dams can severely affect sensitive species, opportunistic omnivores may exploit newly formed reservoir habitats, potentially reshaping community reassembly in increasingly dammed Neotropical systems.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Occurrence: Evidence Gaps for Non-Native Freshwater Fishes in Brazilian Drylands","authors":"Jônnata Fernandes de Oliveira,&nbsp;José Egberto Mesquita Pinto Júnior,&nbsp;Danielle Peretti","doi":"10.1111/eff.70060","DOIUrl":"https://doi.org/10.1111/eff.70060","url":null,"abstract":"<p>Non-native freshwater fishes are widely reported in inland waters, but occurrence records are often interpreted together with stronger evidence of establishment, reproduction, spread, pathways and impacts. This can overstate what published records support, especially in regions where reservoirs, river-basin transfers and artificial connectivity complicate biogeographic interpretation. We reviewed published evidence on non-native freshwater fishes in Caatinga-associated aquatic systems of the Brazilian semi-arid region. Searches in Scopus, Web of Science and SciELO retrieved 508 records; after screening and full-text assessment, 65 studies were included. Each study or species-record was coded in a structured evidence matrix for spatial coverage, habitat type, taxonomic identity, author terminology, biogeographic status and evidence dimensions. Occurrence was the dominant evidence type, whereas establishment, reproduction, spread, pathways and impacts were less frequently documented. Reservoirs, dams and river-basin contexts were the most common settings, although natural systems, coastal drainages and water-transfer systems also contributed to the evidence base. Cichlids (six named species), poeciliids (four species) and sciaenids (one species) concentrated many species-records. The review separated species exotic to Brazil from species native to Brazil but recorded outside their expected basin or drainage. This distinction helps avoid treating all non-native records as evidence of invasion. The findings show that assessments of non-native freshwater fishes should distinguish presence from persistence, reproduction, dispersal, pathway and ecological effect. The proposed evidence framework can support monitoring, data review and management decisions in freshwater systems where introductions, basin transfers and artificial connectivity complicate interpretation of non-native records.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal Shifts in Collective Behaviour of Floodplain-Associated Schooling Fish","authors":"Adam H. Quade,&nbsp;Kelly S. Boyle,&nbsp;Guillaume Rieucau","doi":"10.1111/eff.70061","DOIUrl":"https://doi.org/10.1111/eff.70061","url":null,"abstract":"<div>\u0000 \u0000 <p>Seasonal flood pulses are associated with environmental variability in large river-floodplain ecosystems, yet the influence on schooling fish remains poorly understood. We used high-resolution imaging sonar to conduct the first in situ assessment of collective behaviour in a Lower Mississippi River Basin floodplain habitat in order to test the hypothesis that floodplain-associated schooling fish alter their collective behaviour in response to changes in floodplain connectivity. As schooling is known to be an adaptive strategy, greater behavioural plasticity would allow schooling individuals to appropriately react to changes in environmental conditions, predation risk and foraging opportunities. We recorded 56 h of video across sites located near and far from the initial point of floodplain inundation during connected (high-water) and disconnected (low-water) periods spanning all four seasons. School area, alignment (polarisation) and inter-individual distance (nearest-neighbour distance) were quantified from 5085 schools comprising 120,114 individuals using a semi-automated approach. Smallest school areas were observed at near sites during disconnected-fall. Schools at the far sites during connected-summer were typically of a larger area than disconnected-summer at near or far sites. Fish swam in a more aligned fashion during connected-summer, while inter-individual distances were lowest during connected-spring and disconnected-summer. Results suggest schooling fish inhabiting the floodplain exhibit behavioural changes at the level of their collective in response to changes in the local environmental conditions. Our findings extend the flood pulse concept beyond traditional assemblage-level response by demonstrating that floodplain connectivity is associated with shifts in the collective behaviour of schooling fishes inhabiting this dynamic environment.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"35 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}