Environmental DNA最新文献

{"title":"An Optimized Probe-Based qPCR Assay for the Detection and Monitoring of the Invasive Lionfish (Pterois volitans) in the Atlantic","authors":"Katherine Viehl,&nbsp;Zain Khalid,&nbsp;Kathryn Greiner-Ferris,&nbsp;Eli Taub,&nbsp;Pavithiran Amirthalingam,&nbsp;Girish Kumar,&nbsp;Victoria Marciante,&nbsp;Michelle R. Gaither","doi":"10.1002/edn3.70078","DOIUrl":"https://doi.org/10.1002/edn3.70078","url":null,"abstract":"<p>The Indo-Pacific lionfish, <i>Pterois volitans,</i> is an invasive species in the western Atlantic. Since its introduction to Florida in the early 1980s, populations have surged with lionfish now found from North Carolina to Venezuela. As their range expands, these generalist predators threaten native fauna, and while they are primarily a marine species, their tolerance for low salinity conditions may allow them to expand into sensitive estuarine habitats undetected. Traditional approaches for tracking invasive species such as direct observation or trapping are impractical over large spatial scales, making environmental DNA (eDNA) an attractive alternative. Molecular assays, such as those employing quantitative polymerase chain reaction (qPCR), amplify low copy number DNA fragments in environmental samples and are increasingly employed as a complement to traditional methods for the detection of invasive species. Currently, there is one published PCR assay for the detection of lionfish eDNA. However, the specificity of this assay is unverified, and the critical performance parameters limit of detection (LOD) and limit of quantification (LOQ) have not been established. Here we evaluate the efficacy of this assay and show that it is likely to result in false negatives in the western Atlantic. As an alternative, we developed a new TaqMan probe-based qPCR assay that is species-specific for <i>P. volitans</i> and highly sensitive with a LOD of 12 copies per reaction and a LOQ of 598 copies per reaction. While our assay does not amplify the closely related <i>P. miles</i>, which was also introduced in the western Atlantic, the low prevalence of this species in the invasive population means our assay is effective for most monitoring purposes. We conclude that our assay is a robust method for the detection of lionfish and can be employed in any habitat, offering new opportunities for controlling the spread of invasive lionfish.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70078","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of the Invasive Round Goby (Neogobius melanostomus) in an Estuarine Seascape Based on eDNA","authors":"Leon Green,&nbsp;Marina Panova,&nbsp;Thomas G. Dahlgren,&nbsp;Alizz Axberg,&nbsp;Matthias Obst,&nbsp;Per Sundberg","doi":"10.1002/edn3.70076","DOIUrl":"https://doi.org/10.1002/edn3.70076","url":null,"abstract":"<p>In marine environments, nonindigenous species (NIS) are especially difficult to manage since they are often first detected when fully established and near impossible to eradicate. The development and implementation of effective monitoring methods for marine NIS are therefore crucial for early detection valuable to management. In this study, we develop and evaluate environmental DNA monitoring using quantitative digital PCR (dPCR) to assess the presence of the euryhaline round goby (<i>Neogobius melanostomus</i>) in a seascape environment close to Scandinavia's largest shipping port. We developed a dPCR assay for the species, targeting a region of the 12S gene, and verified its specificity compared to other locally common species from the gobiid family. Using captive live fish, we also experimentally determined the decaying rate of <i>N. melanostomus</i> DNA in water to a half-life of 9.8 h in 15 ppt salinity and 15°C. Finally, we sampled 10 sites within a 400 km² area using eDNA, fyke nets, and baited remote video to validate the accuracy of the water samples to predict the presence and abundance of the species. We found that the number of DNA copies extracted from the water samples varied strongly at sites where <i>N. melanostomus</i> were caught in nets or on video, but the average value from four water samples significantly correlated with an average value from four video samples and also with the total catch at each site. The eDNA assay also detected signals from the species at sites where no fish were caught by fishing or on video. These results show that this method is sensitive for the species at low abundance, and with enough replicates, it can be possible to determine the relative abundance between sites.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time PCR Assay and Environmental DNA Workflow for Detecting Irukandji Jellyfish, Malo bella (Cubozoa)","authors":"Jessica K. Strickland,&nbsp;Kylie A. Pitt,&nbsp;Michael J. Kingsford,&nbsp;Scott J. Morrissey,&nbsp;Dean R. Jerry","doi":"10.1002/edn3.70071","DOIUrl":"https://doi.org/10.1002/edn3.70071","url":null,"abstract":"<p>The rise in coastal populations and marine activities has intensified challenges posed by hazardous Irukandji jellyfishes, whose stings can cause severe symptoms and sometimes death. Despite their significant impact on health services and marine-related industries, Irukandji jellyfishes remain poorly understood due to the challenges of studying them and the limitations of traditional sampling methods. Genetic methods and environmental DNA (eDNA) offer promising solutions. This study developed and validated a sensitive and specific quantitative PCR assay to detect and monitor <i>Malo bella</i>, an Irukandji jellyfish threatening tourism in Western Australia. <i>M. bella</i>-specific primers and a TaqMan Minor Groove Binding (MGB) probe were designed. The assay demonstrated high specificity, not amplifying non-target species, and sensitivity, with 95.6% efficiency, a slope of −3.43, and an <i>R</i>² value of 0.98. The assay's 95% limit of detection (LoD) was 0.80 eDNA copies/reaction, and the modeled limit of quantification (LoQ) was 13 eDNA copies/reaction. Validation through in silico and in vitro tests confirmed successful detection of <i>M. bella</i> eDNA in all water samples from aquaria and around medusae in the ocean. Sanger sequencing verified the amplification of the target <i>M. bella</i> sequence. This assay improves the ability to study <i>M. bella</i>, addressing critical knowledge gaps on the species' ecology. These include assessing the spatial and temporal distributions of this species and potential detection of early benthic life stages to identify source populations. Such studies will improve management of envenomation risks in tourism hotspots. Future research should explore integrating passive or automated samplers and developing real-time detection assays to further enhance monitoring capabilities and mitigate risks posed by hazardous marine species.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70071","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"There is no Smoke Without Fire: Evaluation of Water eDNA Profile of Yersinia ruckeri to Assess Enteric Redmouth Disease Pathogenesis in Rainbow Trout (Oncorhynchus mykiss)","authors":"Cyril Henard,&nbsp;Hanxi Li,&nbsp;Yajiao Duan,&nbsp;Moonika Marana,&nbsp;Per Kania,&nbsp;Kasper Villumsen,&nbsp;Barbara F. Nowak,&nbsp;Louise von Gersdorff Jørgensen","doi":"10.1002/edn3.70070","DOIUrl":"https://doi.org/10.1002/edn3.70070","url":null,"abstract":"<p>In the past couple of decades, applications of environmental nucleic acids (eDNA and eRNA) analysis methods have expanded rapidly into various research fields. Recently, the World Organisation for Animal Health presented guidelines for the use of eDNA as a biomonitoring tool for disease surveillance in aquaculture. In this paper, the eDNA profile of <i>Yersinia ruckeri</i> was monitored over the course of experimentally induced red mouth disease in rainbow trout. Before and after mortality started, the fish pathogen burden, clinical signs, and immune response were compared to the pathogen burden in the water. Two different concentrations of bacteria were used for the infection, and the effects of handling stress on the fish's immune response were evaluated. In the higher concentration of bacteria, the eDNA profiles from <i>Y. ruckeri</i> were significantly higher compared to control at 3 days post-infection (DPI) whereas the first clinical signs of the disease were reported at the first sampling point (1 DPI), outperforming the eDNA profiles. The first mortalities were recorded at 5 DPI. The handling protocol has increased mortality in fish infected with the lower concentration of bacteria without significant changes in the eDNA profile of <i>Y. ruckeri</i>. The eDNA profiles were significantly correlated with most of the immune genes investigated in this study in the higher concentration of bacteria, and they were primarily involved in the inflammation process (<i>il-6</i>, <i>il-8</i>, <i>il-10</i>) and acute response (<i>saa</i>, <i>hep</i>). The use of environmental DNA is a cost-effective and noninvasive approach for the biomonitoring of disease risks in aquaculture. Nevertheless, this study highlighted eDNA application limitations when the immune status of the fish is altered. A combined approach with eDNA and eRNA should be investigated in future infection experiments to evaluate if eRNA from the host could provide information about the immune status and the risk of increased mortality.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70070","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal and Spatial Dynamics of the Lotic Fish Communities: A Comparison of Coffee Filter-Based Passive eDNA Collection Versus Active eDNA Filtering","authors":"Jelena Mlinarec,&nbsp;Ida Svetličić,&nbsp;Matija Kresonja,&nbsp;Matea Rubinić,&nbsp;Tonko Megyery,&nbsp;Ivana Kaliger,&nbsp;Dominik Mihaljević","doi":"10.1002/edn3.70065","DOIUrl":"https://doi.org/10.1002/edn3.70065","url":null,"abstract":"<p>Environmental DNA (eDNA) metabarcoding is a noninvasive and cost-effective method for fish community monitoring, enabling the determination of both the presence/absence of fish species and their relative quantity in closed systems. However, the integration of these novel eDNA-based methods into current monitoring practices is not straightforward and require standardization of methodological approaches. In this study, we investigated spatial and temporal variation in fish assemblages within two lotic systems in Croatia. Six sampling stations were located alongside the middle section of the river Sava upstream and downstream of Zagreb, and one location in the stream Okićnica. We compared traditional field surveys with two eDNA sampling methodologies: active eDNA filtering and passive eDNA collection. We showed that passive eDNA collection using coffee filters detected fish composition as effectively as active eDNA filtration, providing comparable results in terms of local species richness and spatial variation in fish assemblages. Generally, our eDNA approach detected a greater fish species richness per site than electrofishing. Each single sample captured an average of 18.3 species, from a total of 30 species encountered in the 78 samples. The sites upstream of Zagreb showed significant differences in species read abundance in comparison to the sites downstream. Nonmetric multidimensional scaling (nMDS) plot based on read abundance appeared to be structured according to the type of lotic system, with a clear separation in the two-dimensional space between samples from the river Sava and stream Okićnica and between seasons. A substantial increase in read abundance during spawning periods of certain species was observed, emphasizing the method's utility in unraveling ecological complexities. Altogether, this study exemplifies how eDNA metabarcoding is a powerful tool for community monitoring, providing standardized information that will be valuable for environmental management.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"eDNA Metabarcoding Applications Across Italian Marine Coastal Ecosystems: An Overview","authors":"Alice Tagliabue,&nbsp;Giulia Furfaro,&nbsp;Andrea Galimberti,&nbsp;Antonia Bruno,&nbsp;Lorenzo Zane,&nbsp;Alberto Pallavicini,&nbsp;Stefano Piraino","doi":"10.1002/edn3.70075","DOIUrl":"https://doi.org/10.1002/edn3.70075","url":null,"abstract":"<p>Climate emergency and other anthropogenic pressures urgently call for technological and methodological advances to enhance our ability to protect marine habitats and their ecosystem services. In recent years, environmental DNA (eDNA) metabarcoding has emerged as a powerful tool to achieve an integrative assessment of the environmental health status, through a broad, relatively rapid, and cost-effective taxonomic monitoring of biodiversity at different spatial scales. Here we provide a time-based overview of the applications of the eDNA metabarcoding methodology carried out across diverse Italian marine and coastal habitats, with an <i>in-depth</i> scrutiny of the commonly adopted operative procedures, from sampling to sequencing. The lack of standardization and low replicability in space/time arose as major issues of several monitoring campaigns, preventing appropriate cross-comparability of previous studies. Given the wide potential of eDNA metabarcoding surveys along the Italian coastline, this review aims to boost a wider application of eDNA metabarcoding for biodiversity inventories and to avoid major methodological weaknesses that could compromise the long-term value and broad spatial scope of future monitoring plans.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overwintering Fish Community in Ice-Covered Environments in Hokkaido, Japan, Inferred From Environmental DNA","authors":"Tatsuya Kawakami,&nbsp;Makoto Ozaki,&nbsp;Aya Yamazaki,&nbsp;Daiki Nomura,&nbsp;Akihide Kasai","doi":"10.1002/edn3.70068","DOIUrl":"https://doi.org/10.1002/edn3.70068","url":null,"abstract":"<p>The overwintering ecology of fish in the seasonal ice zones (SIZs) remains largely unexplored owing to methodological limitations. Environmental DNA (eDNA) can reveal the distribution and diversity of fish species in various aquatic environments, thereby offering a possible solution to the methodological limitations of SIZ studies. Therefore, we aimed to detect the overwintering fish community in the ice-covered Saroma-ko Lagoon, located on the Okhotsk Sea coast of Hokkaido, and its inflow, using eDNA metabarcoding. eDNA extracted from under-ice seawater collected from the lagoon yielded 28 fish taxa, predominantly <i>Clupea pallasii</i> based on the relative DNA read abundance. Dissimilarity analysis suggested short-term temporal variations in eDNA composition in under-ice seawater, even at the same site. Nineteen fish taxa, predominantly <i>Tribolodon brandtii</i> and <i>T. hakonensis</i>, were detected in the eDNA extracted from under-ice river water. The high dissimilarity between eDNA results from under-ice seawater and river water suggested segregation of the overwintering community between the lagoon and river. Fish eDNA detected in meltwater from sea ice was assigned to five taxa, suggesting the entrainment of particulate matter containing fish eDNA during ice growth. The true species richness estimated based on eDNA results and discrepancies with historical reports suggest that sampling efforts need to be optimized for ice-covered environments to promote more comprehensive species detection. This study demonstrated the usefulness of using fish eDNA metabarcoding to study the ecology of overwintering fish under ice. Clarifying eDNA shedding patterns, persistence, and dispersal in under-ice environments would improve the reliability of this technique and expand its use in SIZs.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing the Fate of eDNA by Particle Sizes and Molecule Lengths in Recirculating Streams","authors":"Pedro F. P. Brandão-Dias,&nbsp;Elise Snyder,&nbsp;Jennifer L. Tank,&nbsp;Ursula H. Mahl,&nbsp;Brett Peters,&nbsp;Arial J. Shogren,&nbsp;Diogo Bolster,&nbsp;Gary A. Lamberti,&nbsp;Kyle Bibby,&nbsp;Scott P. Egan","doi":"10.1002/edn3.70066","DOIUrl":"https://doi.org/10.1002/edn3.70066","url":null,"abstract":"<p>The detection of environmental DNA (eDNA) has revolutionized aquatic species monitoring, yet interpreting eDNA data remains challenging due to gaps in our understanding of eDNA ecology (i.e., origin, state, transport, and fate) and variability in how eDNA methods are applied across the literature. A crucial aspect of the complexity of eDNA ecology is that eDNA is a heterogeneous mix of components that vary in size and other properties, thereby influencing interactions with the environment in diverse ways. In this study, we explore the interplay between three eDNA particle sizes (the physical dimension of eDNA-containing particles) and two molecule lengths (DNA size in base pairs) in flowing water systems. Specifically, we elucidated the mechanisms governing the removal of different eDNA components using a set of 24 recirculating mesocosms where we varied light and substrate conditions. Consistent with previous observations, our findings revealed substantial differences in the mechanisms of eDNA removal between small and large eDNA particles. In mesocosms with biofilm-colonized substrate, we found higher removal rates for smaller particles, but larger eDNA particles were removed more quickly in presence of any substrate. Importantly, we also found that biofilm removes longer eDNA molecules faster, shedding light on a probable mechanism underlying the longstanding association between eDNA removal and the presence of biofilm. Despite the association between biofilm colonization and faster removal of longer molecules, the two eDNA molecule sizes we analyzed (86 and 387 base pairs) exhibited somewhat consistent behavior. In combination, our observations highlight that particle size is an important predictor of eDNA fate, and that eDNA fate shows few differences across varying molecule lengths. Furthermore, our work suggests that conclusions regarding eDNA ecology from studies utilizing short DNA markers are applicable to metabarcoding applications, which typically use longer marker lengths.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Framework to Unify the Relationship Between Numerical Abundance, Biomass, and Environmental DNA","authors":"Matthew C. Yates,&nbsp;Taylor M. Wilcox,&nbsp;Shannon Kay,&nbsp;Pedro Peres-Neto,&nbsp;Daniel D. Heath","doi":"10.1002/edn3.70073","DOIUrl":"https://doi.org/10.1002/edn3.70073","url":null,"abstract":"<p>Does environmental DNA (eDNA) concentration correlate with numerical abundance (<i>N</i>) or biomass in aquatic organisms? We hypothesize that eDNA can be adjusted to simultaneously reflect both. Building on frameworks developed from the Metabolic Theory of Ecology, we derive two equations to adjust eDNA data to simultaneously reflect both <i>N</i> and biomass using population size structure data and allometric scaling coefficients. We also demonstrate that these equations share model parameters, necessitating the joint estimation of regressions between adjusted eDNA, <i>N</i>, and biomass. Furthermore, our framework can be extended to model how other variables (temperature, taxa, diet, trophic level, etc.) might impact relationships between eDNA, <i>N</i>, and biomass in natural ecosystems. We applied our framework to data from two previously published studies correlating eDNA to Brook Trout (<i>Salvelinus fontinalis</i>) <i>N</i> and biomass. In both case studies, point estimates of the scaling coefficient (<i>b</i>) reflected allometric processes (<i>b</i> = 0.51 and 0.37 for Case Study 1 and 2, respectively), with credible intervals indicating that b likely differed from zero (i.e., eDNA scales with <i>N</i>) and one (i.e., eDNA scales with biomass). Directly estimating the value of b improved estimates of <i>N</i> and biomass relative to assuming b equals 0, which particularly affected the capacity to estimate biomass. However, models assuming eDNA production scaled with biomass (i.e., <i>b</i> = 1) were largely similar to estimating <i>b</i>, implying that assuming eDNA scales linearly with biomass might be a sufficient approximation for some systems. Nevertheless, the framework demonstrates that correlating eDNA directly with either <i>N</i> or biomass (as is commonly done in many studies) inherently necessitates an adjustment to infer the other metric if populations exhibit size structure variation. Collectively, we demonstrate that quantitative eDNA data is unlikely to correspond exactly to either population <i>N</i> or biomass but can be adjusted to simultaneously reflect both.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70073","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invasive Crayfish: Drivers or Passengers of Degradation in Freshwater Ecosystems?","authors":"Jelle A. Dercksen,&nbsp;Maarten J. J. Schrama,&nbsp;Kevin K. Beentjes,&nbsp;Bob N. Bastiaans,&nbsp;Rody Blom,&nbsp;André van Roon,&nbsp;Peter W. Lindenburg,&nbsp;Krijn B. Trimbos","doi":"10.1002/edn3.70062","DOIUrl":"https://doi.org/10.1002/edn3.70062","url":null,"abstract":"<p>Invasive species, such as the freshwater crayfish <i>Procambarus clarkii</i>, reportedly negatively influence the abundance of various aquatic species. Moreover, these invaders are increasingly linked to ecological degradation of aquatic ecosystems, as invaded habitats show increased levels of turbidity, nitrogen, and organic matter concentration. <i>P. clarkii</i> has, among other impacts, been associated with eutrophication in invaded habitats. However, observations suggest that the presence of <i>P. clarkii</i> is often not accompanied by ecosystem degradation, raising the question of whether they are drivers of degradation or function as passive passengers, with the degradation being caused by other stressors. To investigate these contrasting hypotheses, we conducted a full factorial experiment in 24 mesocosms with <i>P. clarkii</i> and nutrient pollution (specifically N, P, and K), a ubiquitous stressor in aquatic ecosystems. Here, we assessed the effects on community compositions of morphologically identified macrophytes and chironomids, as well as the compositions of bacteria, phytoplankton, and diatoms identified using environmental DNA (eDNA) metabarcoding. Nutrient pollution induced significant shifts in macrophyte biomass and in the composition of the bacterial, diatom, and phytoplankton communities. All microbial communities exposed to nutrient pollution initially diverged from the control, after which the bacterial and phytoplankton communities converged back to the control in the final weeks. In contrast, we found only marginal effects of <i>P. clarkii</i>, rendering it unlikely as a significant short- to medium-term driver of the tested biodiversity. As microbial communities respond quickly to changes in the environmental conditions, these results signify that the mesocosms used in the study were relatively stable in spite of the presence of <i>P. clarkii</i>. The crayfish density and timeframe studied may be leveraged as threshold values in the design and execution of freshwater management strategies that aim to avert potential negative impacts of <i>P. clarkii</i> on ecosystem structure. Ultimately, the importance of nutrient pollution is reinforced as a driver of environmental change in aquatic ecosystems.</p>","PeriodicalId":52828,"journal":{"name":"Environmental DNA","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/edn3.70062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}