Cristina Coccia, Cristina Andolina, Alessandra Cera, Davide Taurozzi, Federica Spani, Michael Di Gioacchino, Armida Sodo, Salvatrice Vizzini, Andy J. Green, Massimiliano Scalici
{"title":"Relating Microplastic Contamination to Trophic Ecology of the Highly Invasive Red Swamp Crayfish and Eastern Mosquitofish","authors":"Cristina Coccia, Cristina Andolina, Alessandra Cera, Davide Taurozzi, Federica Spani, Michael Di Gioacchino, Armida Sodo, Salvatrice Vizzini, Andy J. Green, Massimiliano Scalici","doi":"10.1111/fwb.70205","DOIUrl":"10.1111/fwb.70205","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>The red swamp crayfish <i>(Procambarus clarkii</i>) and the eastern mosquitofish (<i>Gambusia holbrooki</i>), native to North America, are highly invasive in temperate aquatic environments worldwide, where they often coexist in a variety of habitats.</li>\u0000 \u0000 \u0000 <li>We used stable isotopes of carbon (δ<sup>13</sup>C) and nitrogen (δ<sup>15</sup>N) to examine the trophic ecology of <i>Procambarus clarkii</i> and <i>Gambusia holbrooki</i> co-existing in the same coastal wetland in Italy and explore potential relationships with microplastic (MP) ingestion.</li>\u0000 \u0000 \u0000 <li><i>Gambusia</i> consistently occupied a higher trophic position than <i>Procambarus</i>, and ingested more MPs per individual. There was strong spatial variation in the degree of niche overlap (0%–70%) between habitats.</li>\u0000 \u0000 \u0000 <li>MPs were found in all individuals of alien species with mean concentrations (±SD) of 5.1 ± 3.2 (items/ind) in <i>Procambarus</i> and 5.8 ± 3.30 (items/ind) in <i>Gambusia</i>. MPs were also found in their potential prey (macroinvertebrates), with concentrations ranging from 0.35 ± 0.2 to 69.8 ± 87.8 items/ind., depending on the taxon. Similar polymer colours (mainly blue) and shape (mainly fibres) were found across all samples. Invertebrates were the primary diet items for both species, with little contribution from detritus and plants. The importance of specific invertebrate prey taxa varied between alien species, as did the percentage of MPs potentially ingested from their prey. We found little evidence of biomagnification, since MP concentration was not correlated with trophic levels, but was higher in <i>Gambusia</i>.</li>\u0000 \u0000 \u0000 <li>The use of stable isotopes, combined with the examination of MPs, provides valuable insights into the role of feeding ecology in MP contamination. Given that <i>Procambarus</i> and <i>Gambusia</i> are also key prey for many terrestrial and aquatic predators, they may act as vectors, facilitating the transfer of MPs across ecosystem boundaries. Further research is needed to better understand the long-term ecological impacts of microplastic contamination across various trophic levels, and to assess the potential risks to higher predators.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147696279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cristina Vieites-Blanco, Héctor Macia, Maria Caballol, Jonàs Oliva
{"title":"Influence of Saprotrophic Phytophthora on the Decomposition Rate of Leaf Litter in Alpine and Mediterranean Streams","authors":"Cristina Vieites-Blanco, Héctor Macia, Maria Caballol, Jonàs Oliva","doi":"10.1111/fwb.70206","DOIUrl":"10.1111/fwb.70206","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>The decomposition of leaf litter from the riparian vegetation is a source of nutrients and organic matter for stream food webs. The decomposition rate is influenced by water temperature, leaf characteristics, and aquatic saprotrophic microbial communities. Although the microbial agents <i>Phytophthora lacustris</i> and <i>Phytophthora gonapodyides</i> are frequently isolated from submerged litter, their ecological role in decomposition and their leaf and temperature preferences are largely unknown.</li>\u0000 \u0000 \u0000 <li>In this study, we surveyed <i>Phytophthora</i> colonisation of naturally occurring leaf litter in 26 streams across an altitudinal gradient in the Pyrenees (NE Spain). At 14 of these sites, we also studied <i>Phytophthora</i> colonisation and decomposition (i.e., area and mass loss) of <i>Alnus, Populus</i> and <i>Quercus</i> leaves for 3 months using baiting bags, mimicking the decomposition of leaves that reach streams during leaf fall in autumn. In both experiments, <i>Phytophthora</i> were isolated and identified by sequencing of the ITS region.</li>\u0000 \u0000 \u0000 <li>Leaf species was the main determinant of decomposition, with <i>Alnus</i> leaves decomposing more rapidly than less labile <i>Quercus</i> leaves. The presence of saprotrophic <i>Phytophthora</i> species also correlated with mass loss, especially in the later stages of decomposition. Altitude and climate had the least impact on decomposition, mainly affecting decomposition at the beginning of the decomposition process. The two most common <i>Phytophthora</i> species in Pyrenean streams were <i>P. lacustris</i> (78% of streams) and <i>P. gonapodyides</i> (75%). <i>Phytophthora lacustris</i> was limited to warmer regions, which could be because it has a higher drought-tolerance than <i>P. gonapodyides</i>. Compared with <i>P. lacustris</i>, <i>P. gonapodyides</i> preferred leaves with a lower nitrogen (N) concentration and a slower decomposition.</li>\u0000 \u0000 \u0000 <li>Overall, leaf litter decomposition was correlated with the presence of saprotrophic <i>Phytophthora</i> species: <i>P. gonapodyides</i> was found in leaves that were less decomposed (across N-rich and N-poor litter species) than those of <i>P. lacustris</i>, indicating that they may play different roles in the decomposition process. These species differed in their tolerance to higher and lower temperatures and in their leaf chemical composition preference and, therefore, their ecological niche also differed.</li>\u0000 \u0000 \u0000 <li>Predicted temperature increases could reduce the potential distribution of <i>P. gonapodyides</i>, but the implications for the decomposition of N-poor litter at the early stage of the decomposition process would depend on the extent of the contribution of <i>P. gonapodyides</i> to ","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147696258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gina Walsh, Josie South, Darragh J. Woodford, Melanie L. J. Stiassny, Jérôme Y. Gaugris, Valdie N. Boukaka-Mikembi, Allison A. Pease
{"title":"Trophic Diversity in Aquatic Food Webs Along a Tropical Coastal River Continuum in West-Central Africa","authors":"Gina Walsh, Josie South, Darragh J. Woodford, Melanie L. J. Stiassny, Jérôme Y. Gaugris, Valdie N. Boukaka-Mikembi, Allison A. Pease","doi":"10.1111/fwb.70197","DOIUrl":"10.1111/fwb.70197","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70197","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147696326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fan Wu, Jiajia Li, Xianrui Ha, Junjie Jia, Yang Gao
{"title":"Response of Carbon, Nitrogen and Sulfur Coupling Characteristics to Microbially-Driven Hydro-Environmental Fluctuations in a Typical Floodplain Lake System","authors":"Fan Wu, Jiajia Li, Xianrui Ha, Junjie Jia, Yang Gao","doi":"10.1111/fwb.70199","DOIUrl":"10.1111/fwb.70199","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>In lakes, complex microbially-driven coupling of nutrient cycling processes and associated mechanisms remains unclear. Accordingly, this study systematically investigates the spatial heterogeneity of microbially regulated carbon (C), nitrogen (N) and sulfur (S) cycling processes, their associated functional genes, key functional taxa and dominant factors in a typical floodplain lake (Poyang Lake).</li>\u0000 \u0000 \u0000 <li>We analysed the spatial heterogeneity of functional pathways, functional genes and the key microbial taxa involved in C, N and S cycling across areas with different hydrological conditions within a floodplain lake. Correlations between cycling of C, N and S were further examined at both the functional gene and metagenome-assembled genomes (MAGs) levels. In addition, we identified the potential factors influencing the putative coupling of C, N and S cycling processes and how they are shaped by spatial variation in hydrological conditions.</li>\u0000 \u0000 \u0000 <li>Results revealed an overall lower abundance of functional pathways and genes involved in C, N and S cycling in the sub-lake area compared to the channel and main lake areas. The functional gene co-occurrence network and MAGs-based analysis revealed that the coupling of C, N and S cycling in the sub-lake area was less complex and less restricted than expected, with higher modularity than the channel and main lake areas. The most important factors controlling potential coupled C, N and S cycles in the channel and the main lake areas were concentrations of nitrate nitrogen (NO<sub>3</sub><sup>−</sup>-N), dissolved organic carbon (DOC) and pH levels. Conversely, dissolved total nitrogen (DTN), conductivity (COND) and NO<sub>3</sub><sup>−</sup>-N were mainly responsible for the linkage of C, N and S cycling processes in the sub-lake area.</li>\u0000 \u0000 \u0000 <li>Seven medium-quality MAGs were found to contain multiple functional genes responsible for C, N and S cycling processes, suggesting a potential microbial basis for the coupling. Networks of C, N and S functional genes and comparison with null models further strengthened the evidence for such coupling. Microbially mediated redox reactions and organic matter decomposition were the main processes behind the potentially coupled C, N and S cycles, which were more intense in the main lake and channel areas than sub-lake areas.</li>\u0000 \u0000 \u0000 <li>This study elucidates key processes and putative coupling mechanisms of C, N and S cycling and their associated driving factors while highlighting the importance of hydrological processes in characterising the regional distribution of microbial functions in a floodplain lake system. Our findings are intended to help accurately assess the role of lakes in global nutrient cycles.</li>\u0000 ","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147696425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. G. T. Anscombe, S. L. Speir, A. N. Pruitt, K. J. Cutting, J. L. Tank
{"title":"Beet-Based Deicers Interfere With Early Stage Decomposition of Labile Leaf Litter","authors":"C. G. T. Anscombe, S. L. Speir, A. N. Pruitt, K. J. Cutting, J. L. Tank","doi":"10.1111/fwb.70189","DOIUrl":"https://doi.org/10.1111/fwb.70189","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>Salinization threatens water quality in freshwater ecosystems during the winter in urban areas where road salt is applied to maintain safe driving conditions. To minimise salinization from road salt, some municipalities have shifted to ‘eco-friendly’ alternatives, such as a mixture of beet molasses and salt brine for deicing. While the reduction in chloride application has been the motivation to shift to beet-brine, few studies have explored the effects on ecosystem function in freshwater ecosystems that receive beet-brine runoff.</li>\u0000 \u0000 \u0000 <li>Our study compared the effects of beet-brine versus traditional chloride salts on leaf litter decomposition using replicated recirculating stream mesocosms. We quantified respiration of leaf associated microbial communities (hereafter, biofilms), leaf toughness and decomposition (as mass loss) over a two-week period for a labile (sugar maple; <i>Acer saccharum</i>) and recalcitrant (post oak; <i>Quercus stellata</i>) leaf species under five treatments: control (+0 g L<sup>−1</sup> Cl<sup>−</sup>), low-beet (+0.15 g L<sup>−1</sup> beet-brine), high-beet (+1.5 g L<sup>−1</sup> beet-brine), low-salt (+0.21 g L<sup>−1</sup> Cl<sup>−</sup>) and high-salt (+2.1 g L<sup>−1</sup> Cl<sup>−</sup>).</li>\u0000 \u0000 \u0000 <li>Our results indicate that high beet-brine application decreased initial (< 7d) decomposition rates for sugar maple leaves (high-beet-brine k = 0.017 d<sup>−1</sup>, control k = 0.026 d<sup>−1</sup>), which was likely driven by the addition of labile beet-based carbon. However, we did not observe effects of beet-brine on mass loss after the first 7 days of decomposition. We found that oak leaf toughness decreased in each of our deicing treatments, likely due to added Cl<sup>−</sup>.</li>\u0000 \u0000 \u0000 <li>We observed that the beet-brine addition had a larger effect on leaf litter decomposition and respiration than the equivalent concentration of traditional road salts. We did not observe differences between low salt and high salt treatments in any of our response metrics. Our findings indicate that managers should practice caution when using “eco-friendly” products and emphasise the need to reduce the application of all deicing products. Future research is needed to quantify the inputs and residence time of beet-brine products in freshwater ecosystems.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Seasonal Environmental Conditions and River Morphology Shape Summer Phytoplankton Communities","authors":"Kathi Jo Jankowski, James H. Larson, John Manier","doi":"10.1111/fwb.70195","DOIUrl":"10.1111/fwb.70195","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. G. T. Anscombe, S. L. Speir, A. N. Pruitt, K. J. Cutting, J. L. Tank
{"title":"Beet-Based Deicers Interfere With Early Stage Decomposition of Labile Leaf Litter","authors":"C. G. T. Anscombe, S. L. Speir, A. N. Pruitt, K. J. Cutting, J. L. Tank","doi":"10.1111/fwb.70189","DOIUrl":"10.1111/fwb.70189","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>Salinization threatens water quality in freshwater ecosystems during the winter in urban areas where road salt is applied to maintain safe driving conditions. To minimise salinization from road salt, some municipalities have shifted to ‘eco-friendly’ alternatives, such as a mixture of beet molasses and salt brine for deicing. While the reduction in chloride application has been the motivation to shift to beet-brine, few studies have explored the effects on ecosystem function in freshwater ecosystems that receive beet-brine runoff.</li>\u0000 \u0000 \u0000 <li>Our study compared the effects of beet-brine versus traditional chloride salts on leaf litter decomposition using replicated recirculating stream mesocosms. We quantified respiration of leaf associated microbial communities (hereafter, biofilms), leaf toughness and decomposition (as mass loss) over a two-week period for a labile (sugar maple; <i>Acer saccharum</i>) and recalcitrant (post oak; <i>Quercus stellata</i>) leaf species under five treatments: control (+0 g L<sup>−1</sup> Cl<sup>−</sup>), low-beet (+0.15 g L<sup>−1</sup> beet-brine), high-beet (+1.5 g L<sup>−1</sup> beet-brine), low-salt (+0.21 g L<sup>−1</sup> Cl<sup>−</sup>) and high-salt (+2.1 g L<sup>−1</sup> Cl<sup>−</sup>).</li>\u0000 \u0000 \u0000 <li>Our results indicate that high beet-brine application decreased initial (< 7d) decomposition rates for sugar maple leaves (high-beet-brine k = 0.017 d<sup>−1</sup>, control k = 0.026 d<sup>−1</sup>), which was likely driven by the addition of labile beet-based carbon. However, we did not observe effects of beet-brine on mass loss after the first 7 days of decomposition. We found that oak leaf toughness decreased in each of our deicing treatments, likely due to added Cl<sup>−</sup>.</li>\u0000 \u0000 \u0000 <li>We observed that the beet-brine addition had a larger effect on leaf litter decomposition and respiration than the equivalent concentration of traditional road salts. We did not observe differences between low salt and high salt treatments in any of our response metrics. Our findings indicate that managers should practice caution when using “eco-friendly” products and emphasise the need to reduce the application of all deicing products. Future research is needed to quantify the inputs and residence time of beet-brine products in freshwater ecosystems.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Issue Information - Cover and Ed Board","authors":"","doi":"10.1111/fwb.70204","DOIUrl":"10.1111/fwb.70204","url":null,"abstract":"","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"71 4","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}