Aquatic Sciences最新文献

{"title":"Hydrological regime and river condition shape the feeding ecology of an invasive bivalve in a Neotropical floodplain","authors":"Gabriela Sponchiado Hein,&nbsp;Vinícius Andrade Urbano,&nbsp;Larissa da Silva Pinha,&nbsp;Jaqueline Dantas da Silva,&nbsp;Aline Rosado,&nbsp;Matheus Maximilian Ratz Scoarize,&nbsp;Evanilde Benedito,&nbsp;Roger Paulo Mormul","doi":"10.1007/s00027-026-01338-8","DOIUrl":"10.1007/s00027-026-01338-8","url":null,"abstract":"<div><p>Invasive bivalves alter energy pathways in freshwaters, but their trophic dynamics in floodplain systems under varying levels of human impacts remain unclear. We investigated how trophic status, river regulation and flood pulse shape the diet and isotopic niche of the invasive bivalve<i> Limnoperna fortunei</i> (Dunker 1857) in two large rivers of a Neotropical floodplain: an oligotrophic, dam-regulated, highly impacted river (HIR) and a meso-eutrophic, free-flowing, moderately impacted river (MIR), across dry, rising and flood phases. We sampled <i>L. fortunei</i> and food resources (phytoplankton, zooplankton, periphyton, macrophytes, riparian vegetation, sediment, particulate organic carbon and methanotrophic bacteria) and used stable isotopes of carbon (δ¹³C) and nitrogen (δ¹⁵N), Bayesian mixing models and isotopic niche metrics (standard ellipse areas) to quantify dietary contributions and trophic niche breadth. Autochthonous resources dominated the diet in both rivers, but their identity and relative importance varied: in the HIR, <i>L. fortunei</i> shifted from a phytoplankton-dominated diet (dry) to increasing reliance on macrophytes and zooplankton (flood); whereas in the MIR, macrophytes remained the main dietary source year-round, with the consumption of riparian vegetation increasing during floods and methane-derived carbon contributing modestly to the diet. Isotopic niche area was larger in the HIR and expanded from dry to flood phases in both systems, doing so abruptly in the HIR and gradually in the MIR. Overall, <i>L. fortunei</i> tracks spatiotemporal variation in resource availability and maintains a broad trophic niche, particularly in degraded, regulated environments. This trophic plasticity enhances invasion success and highlights how hydrological alteration and land use change can favour invasive consumers in floodplain rivers worldwide.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-026-01338-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental drivers of aquatic macrophyte composition and beta diversity of Southern Amazonian River Basins","authors":"Milton Omar Córdova,&nbsp;Christian Gabriel da Silva,&nbsp;Diego Taquini de Araujo,&nbsp;Hanna Beatriz Macedo,&nbsp;Domingos de Jesus Rodrigues,&nbsp;Cássia Beatriz Rodrigues Munhoz","doi":"10.1007/s00027-026-01341-z","DOIUrl":"10.1007/s00027-026-01341-z","url":null,"abstract":"<div><p>We investigated the effects of environmental temporality (temporary and permanent aquatic systems) and vegetation type on the beta diversity of aquatic macrophytes across major river basins in southern Amazonia. We analyzed aquatic macrophyte diversity across hierarchical basin scales, partitioning beta diversity into turnover and nestedness components, and related community composition to environmental temporality, vegetation type, and spatial structure. A regional checklist was compiled and classified by vegetation type and hydrographic level across the Tapajós, Xingu, Madeira, Araguaia, and Upper Paraguai basins. Floristic similarity was highest between the Tapajós and Xingu basins (48%) and lowest between Araguaia and all other basins (&lt; 10%). Beta diversity increased with spatial scales, mainly driven by species turnover in Tapajós, Xingu, and Madeira basins. Temporary aquatic environments exhibited lower species similarity within and among basins, reflecting their dynamic and heterogeneous nature. These patterns were consistent across different vegetation types, indicating that hydroperiod has a stronger influence on species composition than surrounding terrestrial vegetation. Overall, aquatic macrophyte assemblages in southern Amazonian basins are compositionally distinct and strongly structured by the permanence of aquatic environments. Temporary systems emerge as key determinants of regional beta diversity of macrophytes, underscoring their ecological importance and vulnerability to hydrological changes.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-026-01341-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable management of the Egyptian Nile Delta-Mediterranean coast: bibliometric and strengths, weaknesses, opportunities, and threats analyses of emerging trends and prospects","authors":"Khaled M. Abdelsalam,&nbsp;Gehan M. El Zokm,&nbsp;Tarek M. El-Geziry,&nbsp;Ahmed E. Alprol,&nbsp;Ahmed El Gendy,&nbsp;Manal G. Eloffy,&nbsp;Suzan El Gharabawy,&nbsp;Amr Z. Hamouda","doi":"10.1007/s00027-026-01332-0","DOIUrl":"10.1007/s00027-026-01332-0","url":null,"abstract":"<div><p>The sustainability of the Nile Delta is threatened by urban expansion, water scarcity, pollution, and climate change. However, there is a lack of comprehensive, data-driven syntheses that map research trends, identify gaps, and outline prospects for this region. To the best of our knowledge, this review is the first comprehensive effort to address this critical information gap. Given the challenges confronting the Nile Delta, this review presents a systematic bibliometric analysis and a strengths, weaknesses, opportunities, and threats analysis of sustainability research undertaken in the region. It highlights critical knowledge gaps, including a lack of information on climate adaptation and pollution management for the region, and outlines a roadmap for future interdisciplinary research and technological innovation. The integration of bibliometric mapping, statistical gap analysis, and artificial intelligence-based environmental monitoring is used to generate actionable insights and a forward-looking vision for the sustainable management of this region. This vision emphasizes adaptive water resource management to address freshwater scarcity, salinisation, and pollution, and thus aligns with the agenda of Egypt's Vision 2030 and the United Nations Sustainable Development Goals for a green economic transition. The recommendations given in this review for the sustainable development of the Nile Delta emphasize the need for integrated coastal zone management. The most critical measures that need to be undertaken include enhancing the monitoring of infrastructure and implementing climate adaptation strategies. Urban and industrial planning must incorporate vulnerability assessments and risk mitigation. Water quality improvement efforts should focus on wastewater treatment, nutrient reduction, and sustainable management of the Nile River. Integrated water resource management and forecasting systems, supported by comprehensive datasets and policy interventions, are essential for this.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 4","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Riparian buffers function as bidirectional filters and hotspots for the removal of riverine microcystin","authors":"Yitong Su,&nbsp;Ziyi Chu,&nbsp;Ya-Jou Chen,&nbsp;Renee Richer,&nbsp;Chuanhui Gu","doi":"10.1007/s00027-026-01336-w","DOIUrl":"10.1007/s00027-026-01336-w","url":null,"abstract":"<div><p>Microcystins (MCs), a group of highly toxic compounds produced by cyanobacteria, pose risks to both aquatic and terrestrial ecosystems. Though riparian buffers are widely recognized for their role in mitigating land-sourced pollution, their capacity to attenuate riverborne MCs remains understudied. In this study, we combined field monitoring, laboratory column experiments, and microbial community analyses to evaluate the capacity of riparian soils to remove MCs under dynamic river-groundwater exchange. Field data collected from a tidal river revealed bidirectional hydraulic gradients and elevated MC concentrations in groundwater wells during the river infiltration phase, suggesting that riverine MCs can intrude into riparian zones. Meanwhile, the flow-through column experiment demonstrated 90% MC mass retention relative to chloride, with first-order degradation rate constants ranging from 1.02 to 1.15 day⁻¹. Microbial analyses revealed that riparian soils harbored <i>Sphingomonas</i>, <i>Novosphingobium,</i> and other taxa with MC-degrading potential. Furthermore, key genes associated with MC degradation were identified in the samples. These findings highlight the role of riparian buffers as overlooked filters for riverborne MCs. Understanding the fate of MCs in riparian systems can further inform watershed management strategies to mitigate cyanotoxin pollution in aquatic environments.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetic model for aerobic mineralization of labile and refractory dissolved organic matter: an experimental approach","authors":"Rafael S. Panhota,&nbsp;Marcela B. Cunha-Santino,&nbsp;Armando H. H. Vieira,&nbsp;Irineu Bianchini Jr.","doi":"10.1007/s00027-026-01339-7","DOIUrl":"10.1007/s00027-026-01339-7","url":null,"abstract":"<div><p>In aquatic systems, microbiota composition is strongly related to dissolved oxygen (DO) availability, which modulates the rates of biochemical reactions on decomposition. DO is a key variable that defines the prevalence of metabolic pathways in the well-oxygenated aquatic ecosystems. In this context, this study proposes a kinetic model to describe oxygen consumption due to the degradation of labile and refractory dissolved organic carbon (DOC) in aquatic ecosystems, including stoichiometric ratios of oxygen to carbon for each defined pathway (O/C). The values used for parameterizing the model were derived from in vitro mineralization experiments; for this, DOC samples were collected at three sites in the Barra Bonita Reservoir (São Paulo State, Brazil). The model was developed considering two pathways for mineralization, the oxidation of labile and refractory DOC. The mineralization of labile and refractory DOC follows distinct pathways, with different reaction times (average half-life values: 1 and 267 days, respectively). On average, the stoichiometric O/C ratios (1.81 and 2.13 for refractory and labile carbon, respectively) obtained were lower than expected, given the C-compound oxidation as a reference (2.67). In addition to the reaction rate values, the O/C values found in this study provide the orders of magnitude and the amplitudes of these relationships. Knowledge of these parameters and the use of this proposed model can contribute to a better understanding of oxygen consumption processes in aquatic environments, providing accurate information on oxygen balance to the calibration of water quality models.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-026-01339-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of dissolved organic carbon in hydrologically distinct sub-lakes of Poyang Lake: the roles of hydrological connectivity, nutrients, and phytoplankton","authors":"Kuimei Qian,&nbsp;Yuwei Chen,&nbsp;Xueyang Zhang,&nbsp;Shuya Wang,&nbsp;Jinfu Liu,&nbsp;Wei Li","doi":"10.1007/s00027-026-01340-0","DOIUrl":"10.1007/s00027-026-01340-0","url":null,"abstract":"<div><p>Dissolved organic carbon (DOC) is a critical component of aquatic carbon cycling and a key indicator of water quality in lake ecosystems. As the largest river-connected freshwater lake in China, Poyang Lake exhibits dramatic seasonal water level fluctuations (WLFs) and substantial spatial heterogeneity in hydrological connectivity. However, the drivers and mechanisms regulating DOC dynamics across its hydrologically distinct sub-lakes remain poorly understood. Based on quarterly monitoring data (2019–2022) from ten sampling sites in two typical regions—the relatively enclosed Cuoji Lake and the highly interconnected Nanji Wetland—this study investigated the spatiotemporal variations of DOC and identified the dominant controlling factors. Results showed that DOC concentrations in Cuoji Lake ranged from 0.54 to 4.61 mg/L (mean: 2.46 ± 0.07 mg/L) with significant seasonal fluctuations, peaking in the dry season (January: 3.52 mg/L) and declining in the flood season (July: 2.58 mg/L). In contrast, DOC in Nanji Wetland varied from 1.52 to 9.61 mg/L (mean: 3.82 ± 1.72 mg/L) without significant temporal variation. The correlation heatmap revealed no significant relationship between DOC and water level in either sub-lake, indicating that WLFs are not the dominant driver. Instead, hydrological connectivity, shaped by geomorphological enclosure, mediated DOC responses. Cuoji Lake’s seasonal DOC pattern was modulated indirectly by hydrological changes, while Nanji Wetland’s stability reflected a balance between allochthonous inputs and autochthonous production. Additionally, DOC was positively correlated with nutrients (NH₄⁺-N, PO_₄³⁻-P, TP), COD, chlorophyll a, and phytoplankton biomass, highlighting joint regulation by internal biogeochemical processes. These findings clarify the multi-factor regulation of DOC in hydrologically heterogeneous sub-lakes, emphasizing hydrological connectivity, organic matter sources, nutrients, and phytoplankton rather than water level as the main regulators shaping DOC dynamics in Poyang Lake’s sub‑lakes. The results provide scientific support for carbon cycling assessment and water quality management in large river-connected lakes.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Do birds respond to the urban stream syndrome?","authors":"Jorge M. Santos,&nbsp;Maria João Feio,&nbsp;Ana R. Calapez,&nbsp;Sonia R. Q. Serra,&nbsp;Andreína Zerega,&nbsp;Zara Teixeira,&nbsp;Jaime A. Ramos","doi":"10.1007/s00027-026-01331-1","DOIUrl":"10.1007/s00027-026-01331-1","url":null,"abstract":"<div><p> Riparian vegetation acts as a transition zone between aquatic and terrestrial ecosystems and plays an important role in ecosystem functioning. In this study, we aimed to assess the response of bird communities to the ecological degradation of stream ecosystems by urbanisation, and assess their potential as ecological indicators of lotic ecosystems beyond aquatic macroinvertebrate communities. For that purpose, we selected 15 urban streams (Coimbra, Portugal), covering an urbanisation gradient. We performed a bird survey to characterise existing communities in the riparian areas and stream channels. In addition, we characterised the aquatic macroinvertebrate communities, a well-established biological quality element of rivers, the physicochemical quality of the water, the hydromorphological conditions and riparian vegetation structure. The bird assemblage composition was strongly influenced by riparian vegetation cover, habitat quality and hydromorphological alterations. The number of insectivorous bird species was positively associated with tree and shrub cover, and negatively correlated with riparian degradation, while those of granivorous birds increased in more urbanised areas and degraded ecosystems. Multidimensional patterns of bird assemblages in the urban streams could be discriminated into two groups, which were related to either better or poorer environmental conditions. There was only a partial correspondence of these patterns with the biological quality classification of streams given by the macroinvertebrate data. A biological-environmental correlation analysis further highlighted that riparian vegetation structure and composition, along with hydromorphological quality and water quality, explained the composition of both bird and invertebrate assemblages, although the former were more relevant for the bird communities. We conclude that bird distribution may provide valuable information on riparian integrity and may serve as a complementary tool for the evaluation of the ecological condition of urban streams.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-026-01331-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variation of dissolved organic matter in a low-order river associated with a North Patagonian relict of evergreen native forest (Valdivia, 39°S, Chile)","authors":"Carlos Esse,&nbsp;Francisco Encina-Montoya,&nbsp;José Tomás Valenzuela,&nbsp;Daniela Rivera-Ruiz,&nbsp;Francisco Correa-Araneda,&nbsp;Patricio De los Ríos-Escalante,&nbsp;Claudia Alvarado-Flores,&nbsp;Jorge Nimptsch","doi":"10.1007/s00027-026-01316-0","DOIUrl":"10.1007/s00027-026-01316-0","url":null,"abstract":"<div><p>Dissolved organic matter (DOM) is an important component of freshwater ecosystems, in which it partially originates from the decomposition of detritus in surrounding soils. Its composition serves as a reliable indicator of water quality and ecosystem functioning. Streams flowing through native forests, where nutrient retention in soils is high, typically exhibit low DOM concentrations, though this varies with soil type and hydrological conditions. This study examined DOM concentrations and composition in a stream catchment located in Valdivia, Chilean North Patagonia (39°S), which is characterized by dominant native forest cover. The aim of this study was to establish baseline values for future comparisons with more anthropogenically influenced catchments. To achieve this, water samples were collected over an 8-month period that encompassed both the dry and rainy seasons, and DOM composition was analyzed using spectrofluorometry and parallel factor analysis. Our results revealed high concentrations of DOM, which predominantly consisted of fluorescent components resembling humic and fulvic acids, particularly during initial precipitation events. Strong positive correlations were observed between all of the identified fluorescence components, while humic ultraviolet absorbance showed significant negative correlations with total precipitation, river flow, dissolved oxygen, turbidity, dissolved organic carbon, and total nitrogen loads. These findings highlight the seasonal dynamics of DOM export, which are driven by precipitation and influenced by biogeochemical interactions. The patterns observed align with those of similar studies undertaken in Chilean North Patagonia, which emphasizes the need for further research to understand the temporal variations of humic substances and their ecological role in aquatic ecosystems. Such insights are critical for informing conservation and management strategies for forest-dominated catchments.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial heterotrophic functional responses to natural salinity fluctuations in hypersaline waters","authors":"Joan Ferriol-Ciurana,&nbsp;Anna M. Romaní,&nbsp;Andrea Butturini,&nbsp;Judit Boadella,&nbsp;Joan Pere Casas-Ruiz","doi":"10.1007/s00027-026-01333-z","DOIUrl":"10.1007/s00027-026-01333-z","url":null,"abstract":"<div><p>Saline lakes in arid and semi-arid regions experience recurrent drying and rain events that cause intense salinity fluctuations. Microorganisms are key actors in saline lakes carbon cycling, yet the development of resistant strategies to cope with extreme and fluctuating salinity conditions may compromise their functioning. Here, we investigate the impact of natural salinity variations on the heterotrophic activity of planktonic microbial communities in the hypersaline lakes of the Monegros area. To this end, a wide range of extracellular enzyme activities together with dissolved organic matter (DOM) quantity and quality were measured at the water column of four playa-lakes under different hydrological conditions. Salinity was the primary factor driving changes in enzyme activities across samples, whereas DOM optical properties remained relatively stable and did not correlate with enzyme activities. At intermediate salinity levels, enzyme activities fell within the range of observed values in freshwater ecosystems, suggesting a full adaptation of the microbial community to hypersalinity. However, when fluctuating towards both extremes of the measured salinity gradient, a concomitant decrease in prokaryote viability and hydrolytic enzyme diversity and activity was observed. We suggest that, under extreme salinity levels, prokaryotes are forced to reduce the energy allocated to enzyme production due to the energy expenditure on osmolytes’ synthesis to counteract osmotic stress. On the other hand, when rain events sharply decrease lakes salinity, prokaryotes must face a fast increase in turgor pressure that reduces their viability and energy allocation to enzyme production. In contrast, phenol oxidase activity steadily increased with salinity, probably as a protection mechanism.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-026-01333-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental filtering and serial discontinuity interactively shape macrobenthic metacommunity assembly along the regulated Oujiang River, China","authors":"Genting Yu,&nbsp;Jihong Xia,&nbsp;Xinyan Zhou,&nbsp;Qiaoxi Zheng,&nbsp;Weijie Cao,&nbsp;Aiju You,&nbsp;Hui Wu,&nbsp;Lei Fu,&nbsp;Jingwen Hu,&nbsp;Lei Hua,&nbsp;Hongqing Zhang,&nbsp;Yongshu Zhu","doi":"10.1007/s00027-026-01335-x","DOIUrl":"10.1007/s00027-026-01335-x","url":null,"abstract":"<div><p>The River Continuum Concept (RCC) provides a foundational template for predicting longitudinal changes in riverine communities. However, how hydraulic engineering modifies these natural gradients in subtropical regulated rivers remains mechanistically poorly understood. In particular, the construction of cascade dams creates serial discontinuity that fundamentally alters environmental filtering processes, yet empirical evidence from Asian monsoon regions—characterized by mountainous terrain and strong anthropogenic pressures—remains scarce. In the study reported here, we investigated how environmental filtering and serial discontinuity interactively shape macrobenthic metacommunity assembly along the main stem of the Oujiang River, a heavily regulated river in southeastern China punctuated by nine cascade dams. Using data from surveys at 24 sites across three seasons, we analyzed taxonomic composition, functional feeding groups, and diversity indices, and their relationships with environmental factors using spatial autocorrelation analysis, non-metric multidimensional scaling (NMDS), and Mantel tests. Our results revealed three key findings. First, macrobenthic community composition differed significantly among reaches (permutational multivariate analysis of variance [PERMANOVA], <i>p</i> = 0.037); however, this longitudinal variation was not a smooth continuum but rather formed distinct compartments shaped by dam-induced discontinuities. Second, environmental filtering dominated metacommunity assembly over dispersal limitation, as evidenced by non-significant spatial autocorrelation (Moran’s<i> I</i>, <i>p</i> &gt; 0.05) and strong species–environment correlations. Flow velocity and substrate composition acted as primary filters, with water quality parameters (5-day biochemical oxygen demand, ammonia nitrogen, electrical conductivity) serving as secondary filters that intensified in mid-to-lower reaches. Third, the interplay between environmental filtering and serial discontinuity produced three metacommunity compartments: upstream reaches dominated by rheophilic aquatic insects; midstream transitional communities shaped by dam-induced flow attenuation and fine sediment accumulation; and downstream estuarine assemblages dominated by pollution-tolerant Mollusca and euryhaline Polychaeta under conditions of organic enrichment and salinity stress. Notably, functional feeding group structure remained relatively stable across reaches despite taxonomic turnover. Our findings advance the mechanistic understanding of regulated river metacommunities by demonstrating that serial discontinuity modifies the type, intensity, and spatial configuration of environmental filters, thereby reorganizing community assembly patterns.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"88 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}