Weicheng Yu, Lei Dong, Zhuoya Li, Ru Huang, Chuanxin Chao, Le Xia, Feng Li
Submerged macrophytes in shallow freshwater ecosystems often encounter fluctuating nutrient and light conditions, which shape their growth strategies and interspecific interactions. However, the combined effects of these environmental factors on competition and trait plasticity remain underexplored.
We investigated interspecific competition and trait responses between Vallisneria natans and Myriophyllum aquaticum using a fully factorial replacement series experiment crossing two light regimes, three nutrient levels, and five planting ratios. The two light regimes were higher-light (206.3 ± 16.8 μmol m−2 s−1) and lower-light (78.4 ± 6.4 μmol m−2 s−1). The three nutrient levels were N1 (ambient; TN = 0.478 mg L−1, TP = 0.001 mg L−1), N2 (low enrichment; TN = 3.0 mg L−1, TP = 0.2 mg L−1), and N3 (high enrichment; TN = 8.0 mg L−1, TP = 0.8 mg L−1). Five planting ratios of V. natans to M. aquaticum were tested: 8:0, 6:2, 4:4, 2:6, and 0:8. We measured plant biomass, morphological traits (plant height, root length, and root-to-shoot ratio), and tissue nutrient concentrations (total nitrogen and total phosphorus). Competition indices including relative yield (RY), relative competition intensity (RCI), and relative crowding coefficient (RCC) were calculated to quantify interspecific interactions.
M. aquaticum exhibited greater biomass and tissue nutrient accumulation (total nitrogen and total phosphorus) under nutrient-rich, higher-light conditions, maintaining competitive dominance. In contrast, V. natans demonstrated higher morphological plasticity and competitive persistence under nutrient-poor and shaded conditions, increasing root-to-shoot ratio, plant height, and root length. These traits reflected a conservative growth strategy that enabled niche differentiation.
Competition indices revealed asymmetric interactions: M. aquaticum strongly suppressed V. natans under enriched conditions (low RY, high RCI), while V. natans showed higher RCC under stress, suggesting context-dependent shifts in competitive advantage.
Our findings highlight the significance of trait-based strategies in mediating macrophyte competition and offer insights into species selection for ecological restoration in variable freshwater environments. Moreover, the strong growth and resource acquisition abilities of M. aquaticum under nutrient-rich and well-lit conditions may also underpin its invasive success in eutrophic freshwater ecosystems.
{"title":"Nutrient and Light Interactions Shape Competitive Dynamics Between Two Co-Occurring Submerged Macrophytes","authors":"Weicheng Yu, Lei Dong, Zhuoya Li, Ru Huang, Chuanxin Chao, Le Xia, Feng Li","doi":"10.1111/fwb.70147","DOIUrl":"https://doi.org/10.1111/fwb.70147","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>Submerged macrophytes in shallow freshwater ecosystems often encounter fluctuating nutrient and light conditions, which shape their growth strategies and interspecific interactions. However, the combined effects of these environmental factors on competition and trait plasticity remain underexplored.</li>\u0000 \u0000 \u0000 <li>We investigated interspecific competition and trait responses between <i>Vallisneria natans</i> and <i>Myriophyllum aquaticum</i> using a fully factorial replacement series experiment crossing two light regimes, three nutrient levels, and five planting ratios. The two light regimes were higher-light (206.3 ± 16.8 μmol m<sup>−2</sup> s<sup>−1</sup>) and lower-light (78.4 ± 6.4 μmol m<sup>−2</sup> s<sup>−1</sup>). The three nutrient levels were N1 (ambient; TN = 0.478 mg L<sup>−1</sup>, TP = 0.001 mg L<sup>−1</sup>), N2 (low enrichment; TN = 3.0 mg L<sup>−1</sup>, TP = 0.2 mg L<sup>−1</sup>), and N3 (high enrichment; TN = 8.0 mg L<sup>−1</sup>, TP = 0.8 mg L<sup>−1</sup>). Five planting ratios of <i>V. natans</i> to <i>M. aquaticum</i> were tested: 8:0, 6:2, 4:4, 2:6, and 0:8. We measured plant biomass, morphological traits (plant height, root length, and root-to-shoot ratio), and tissue nutrient concentrations (total nitrogen and total phosphorus). Competition indices including relative yield (RY), relative competition intensity (RCI), and relative crowding coefficient (RCC) were calculated to quantify interspecific interactions.</li>\u0000 \u0000 \u0000 <li><i>M. aquaticum</i> exhibited greater biomass and tissue nutrient accumulation (total nitrogen and total phosphorus) under nutrient-rich, higher-light conditions, maintaining competitive dominance. In contrast, <i>V. natans</i> demonstrated higher morphological plasticity and competitive persistence under nutrient-poor and shaded conditions, increasing root-to-shoot ratio, plant height, and root length. These traits reflected a conservative growth strategy that enabled niche differentiation.</li>\u0000 \u0000 \u0000 <li>Competition indices revealed asymmetric interactions: <i>M. aquaticum</i> strongly suppressed <i>V. natans</i> under enriched conditions (low RY, high RCI), while <i>V. natans</i> showed higher RCC under stress, suggesting context-dependent shifts in competitive advantage.</li>\u0000 \u0000 \u0000 <li>Our findings highlight the significance of trait-based strategies in mediating macrophyte competition and offer insights into species selection for ecological restoration in variable freshwater environments. Moreover, the strong growth and resource acquisition abilities of <i>M. aquaticum</i> under nutrient-rich and well-lit conditions may also underpin its invasive success in eutrophic freshwater ecosystems.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618892","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}
Jaquelini O. Zeni, Gabriel L. Brejão, Lilian Casatti, Tadeu Siqueira
{"title":"The Ecological Memory of Fish Assemblages in Tropical Agroecosystems With Different History of Landscape Changes","authors":"Jaquelini O. Zeni, Gabriel L. Brejão, Lilian Casatti, Tadeu Siqueira","doi":"10.1111/fwb.70139","DOIUrl":"https://doi.org/10.1111/fwb.70139","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70139","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618976","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}
Letha Louisiana Wantania, Jan Möhring, Thore Koppetsch, Friedrich W. Miesen, Daisy Wowor, Farnis Boneka, Fabian Herder
{"title":"Sulawesi Stream Fish Communities Disconnected From the Sea: Absence of Diadromous and Dominance of Exotic Species","authors":"Letha Louisiana Wantania, Jan Möhring, Thore Koppetsch, Friedrich W. Miesen, Daisy Wowor, Farnis Boneka, Fabian Herder","doi":"10.1111/fwb.70143","DOIUrl":"https://doi.org/10.1111/fwb.70143","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70143","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618886","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}
{"title":"Zooplankton Epibionts in Boreal Lakes: Associations With DOC and Host Community Traits","authors":"Satu Estlander, Jukka Horppila","doi":"10.1111/fwb.70146","DOIUrl":"https://doi.org/10.1111/fwb.70146","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70146","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145601208","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}
{"title":"Issue Information - Cover and Ed Board","authors":"","doi":"10.1111/fwb.14286","DOIUrl":"https://doi.org/10.1111/fwb.14286","url":null,"abstract":"","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 12","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.14286","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145601207","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}
Freya E. Rowland, Michael J. Vanni, Nicole M. Hayes, Clifford E. Kraft
Although nitrogen and phosphorus deficiency of algal blooms have been the focus of substantial attention, organic nutrients can limit algal growth in aquatic systems. Growing evidence indicates thiamine (vitamin B1) can influence the community of primary producers in marine systems, but comparatively little is known about the effect of thiamine on freshwater algal productivity.
We conducted 106 nutrient deficiency experiments with water from 39 Ohio lakes of varying trophic status during the growing seasons (April–October) of 2008–2009. Specifically, we tested the response of phytoplankton biomass (as chlorophyll a, chl-a) relative to controls to added nitrogen (N), phosphorus (P), thiamine (Th), or combinations of N + P and N + P + Th. Next, we compared the chl-a growth response of treatment/control to published thresholds based on frequentist approaches and compared the conclusions with Bayesian model results that focused on probability of a response.
Although N + P addition was consistently associated with the largest chl-a response, we found evidence of a thiamine influence on phytoplankton growth in some experiments. The Bayesian approach suggested thiamine may become more limiting as the growing season progresses. By late in the growing season, there was an 85% probability of a positive algal growth response to thiamine addition.
Understanding the role of thiamine or other overlooked nutrients is not likely to alter the prevailing understanding of nutrient deficiency in freshwater ecosystems. However, we present evidence that freshwater phytoplankton may experience thiamine deficiency and suggest limnologists consider thiamine when exploring resource deficiencies.
{"title":"Potential Thiamine Deficiency of Phytoplankton Across a Productivity Gradient and Seasons in Ohio Lakes","authors":"Freya E. Rowland, Michael J. Vanni, Nicole M. Hayes, Clifford E. Kraft","doi":"10.1111/fwb.70134","DOIUrl":"https://doi.org/10.1111/fwb.70134","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>Although nitrogen and phosphorus deficiency of algal blooms have been the focus of substantial attention, organic nutrients can limit algal growth in aquatic systems. Growing evidence indicates thiamine (vitamin B<sub>1</sub>) can influence the community of primary producers in marine systems, but comparatively little is known about the effect of thiamine on freshwater algal productivity.</li>\u0000 \u0000 \u0000 <li>We conducted 106 nutrient deficiency experiments with water from 39 Ohio lakes of varying trophic status during the growing seasons (April–October) of 2008–2009. Specifically, we tested the response of phytoplankton biomass (as chlorophyll <i>a</i>, chl-<i>a</i>) relative to controls to added nitrogen (N), phosphorus (P), thiamine (Th), or combinations of N + P and N + P + Th. Next, we compared the chl-<i>a</i> growth response of treatment/control to published thresholds based on frequentist approaches and compared the conclusions with Bayesian model results that focused on probability of a response.</li>\u0000 \u0000 \u0000 <li>Although N + P addition was consistently associated with the largest chl-<i>a</i> response, we found evidence of a thiamine influence on phytoplankton growth in some experiments. The Bayesian approach suggested thiamine may become more limiting as the growing season progresses. By late in the growing season, there was an 85% probability of a positive algal growth response to thiamine addition.</li>\u0000 \u0000 \u0000 <li>Understanding the role of thiamine or other overlooked nutrients is not likely to alter the prevailing understanding of nutrient deficiency in freshwater ecosystems. However, we present evidence that freshwater phytoplankton may experience thiamine deficiency and suggest limnologists consider thiamine when exploring resource deficiencies.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 11","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145619136","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}
Jeffrey R. Baldock, Robert Al-Chokhachy, Annika Walters
<div> <p> </p><ol> <li>Landscapes are composed of habitat patches and conditions that vary across space and time. While habitat variability and complexity can support important ecological processes and ecosystem services, the dynamic nature of habitats can also constrain organismal growth and production as optimal conditions are fleeting. In riverine ecosystems, groundwater discharge to streams stabilises water temperature and flow regimes, thus mediating how habitat complexity is expressed. Yet, how stable habitats structure growth and production within the broader landscape matrix is not well understood.</li> <li>In this study, we explored the effects of groundwater on spatiotemporal variation in growth and production for juvenile Yellowstone cutthroat trout (<i>Oncorhynchus virginalis bouvieri</i>) across the upper Snake River catchment, Wyoming, USA. We combined machine learning techniques and remotely sensed landscape data to estimate groundwater availability across the river network, which we linked to stream temperature regimes and conspecific density. We then used Bayesian hierarchical models to quantify the effects of temperature, density and groundwater on spatiotemporal variation in fish growth and production in 52 focal reaches. Finally, we predicted body size trajectories and trends in total production continuously over both space and time to understand the effect of groundwater at the riverscape scale.</li> <li>Groundwater discharged to streams where topography changes abruptly in valley-bottom areas underlain by coarse glacial deposits. Groundwater stabilised temperature regimes and was associated with high trout densities. Temperature and density, in turn, interacted to influence growth rates: growth increased strongly with temperature, but this effect was reduced when density was high. Accordingly, variation in groundwater availability among stream reaches diversified growth and production regimes. In reaches with low groundwater availability, growth and production declined over time from summer maxima. In contrast, in reaches with high groundwater availability, temporal trends in growth and production were hump-shaped—peaking in autumn—and mean production was greater. At the riverscape scale, temporal asynchrony in growth rates generated convergent spatial variation in growth capacity, but—when combined with density—led to the formation of distinct hotspots of production.</li> <li>Our results demonstrate how groundwater, an important driver of aquatic ecosystem heterogeneity, structures trout growth and production across space and time. Importantly, rare, but stable habitats may disproportionately affect ecological processes and serve as key sources of population diversity at larger spatial scales.</li> </ol> </
{"title":"Groundwater Structures Fish Growth and Production Across a Riverscape","authors":"Jeffrey R. Baldock, Robert Al-Chokhachy, Annika Walters","doi":"10.1111/fwb.70112","DOIUrl":"https://doi.org/10.1111/fwb.70112","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>Landscapes are composed of habitat patches and conditions that vary across space and time. While habitat variability and complexity can support important ecological processes and ecosystem services, the dynamic nature of habitats can also constrain organismal growth and production as optimal conditions are fleeting. In riverine ecosystems, groundwater discharge to streams stabilises water temperature and flow regimes, thus mediating how habitat complexity is expressed. Yet, how stable habitats structure growth and production within the broader landscape matrix is not well understood.</li>\u0000 \u0000 \u0000 <li>In this study, we explored the effects of groundwater on spatiotemporal variation in growth and production for juvenile Yellowstone cutthroat trout (<i>Oncorhynchus virginalis bouvieri</i>) across the upper Snake River catchment, Wyoming, USA. We combined machine learning techniques and remotely sensed landscape data to estimate groundwater availability across the river network, which we linked to stream temperature regimes and conspecific density. We then used Bayesian hierarchical models to quantify the effects of temperature, density and groundwater on spatiotemporal variation in fish growth and production in 52 focal reaches. Finally, we predicted body size trajectories and trends in total production continuously over both space and time to understand the effect of groundwater at the riverscape scale.</li>\u0000 \u0000 \u0000 <li>Groundwater discharged to streams where topography changes abruptly in valley-bottom areas underlain by coarse glacial deposits. Groundwater stabilised temperature regimes and was associated with high trout densities. Temperature and density, in turn, interacted to influence growth rates: growth increased strongly with temperature, but this effect was reduced when density was high. Accordingly, variation in groundwater availability among stream reaches diversified growth and production regimes. In reaches with low groundwater availability, growth and production declined over time from summer maxima. In contrast, in reaches with high groundwater availability, temporal trends in growth and production were hump-shaped—peaking in autumn—and mean production was greater. At the riverscape scale, temporal asynchrony in growth rates generated convergent spatial variation in growth capacity, but—when combined with density—led to the formation of distinct hotspots of production.</li>\u0000 \u0000 \u0000 <li>Our results demonstrate how groundwater, an important driver of aquatic ecosystem heterogeneity, structures trout growth and production across space and time. Importantly, rare, but stable habitats may disproportionately affect ecological processes and serve as key sources of population diversity at larger spatial scales.</li>\u0000 </ol>\u0000 \u0000 </","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 11","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145626022","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}
Martin Berggren, Mayra P. D. Rulli, Ann-Kristin Bergström, Ryan A. Sponseller, Geert Hensgens
{"title":"Does Dissolved Organic Matter Composition Help Explain the Concentrations of Bioavailable Macronutrients in Organic Matter-Rich Freshwaters?","authors":"Martin Berggren, Mayra P. D. Rulli, Ann-Kristin Bergström, Ryan A. Sponseller, Geert Hensgens","doi":"10.1111/fwb.70141","DOIUrl":"https://doi.org/10.1111/fwb.70141","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 11","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145619059","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}
{"title":"Cyanobacterial Bloom Development, Nitrogen Fixation and Community Change: Insights on Rapid Change From a Shallow Lake","authors":"Lisa M. Boyer, Scott N. Higgins, Helen M. Baulch","doi":"10.1111/fwb.70131","DOIUrl":"https://doi.org/10.1111/fwb.70131","url":null,"abstract":"<p>\u0000 \u0000 </p>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 11","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.70131","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145572604","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}
Chao Guo, Wei Li, Adam G. Hansen, Shiqi Li, Jie Ke, Erik Jeppesen, Chuansong Liao, Jing Yuan, Tanglin Zhang, Chuanbo Guo, Jiashou Liu
The proliferation of small-bodied fishes and their foraging effects within food webs can limit the growth of submerged macrophytes and degrade water quality in shallow lake ecosystems. The foraging habits of small-bodied fishes vary, and, therefore, ecosystem responses may differ depending on which species or feeding guild that dominates the fish community. Yet, species and feeding guild-specific foraging effects remain poorly understood.
Here, we used an experimental mesocosm to evaluate how water quality and submerged macrophytes respond to different species of small-bodied fishes, including omnivorous bitterling Acheilognathus macropterus (AMA), crucian carp Carassius auratus (CAU), sharpbelly Hemiculter leucisculus (HLE), zooplanktivorous thin sharpbelly Toxabramis swinhonis (TSW) and their mixes (1:1:1:1) (MIX).
Our results showed that the mean weekly total nitrogen, total phosphorus, turbidity, chlorophyll-a and trophic level index values were significantly higher in treatments with fish compared to fish-free controls during the experiment. At the end of the experiment, mean values for the number of submerged macrophyte shoots, leaf number, dry mass and the relative growth rate of shoots were significantly lower in the treatments with than without fish. In addition, mean values for leaf height, leaf width and the dry mass of submerged macrophytes in the TSW treatment were significantly greater than in the CAU, HLE and AMA treatments. Structural equation modelling revealed that small-bodied omnivorous fishes (i.e., crucian carp, sharpbelly and bitterling) affected submerged macrophyte growth more than zooplanktivorous fishes (i.e., thin sharpbelly), driven by their different foraging habits.
Our findings indicated that high abundances of small-bodied fishes have negative effects on water quality and the growth of submerged macrophytes in subtropical shallow lake ecosystems, but the effects differed with fish foraging guild. Control of overabundant small-bodied fishes (especially omnivorous fishes) may facilitate maintenance or effective restoration of submerged macrophytes and subtropical shallow lake ecosystem structure and function.
{"title":"Diverse Foraging in Small-Bodied Fishes: Effects on Water Quality and Submerged Macrophytes in Shallow Subtropical Lake Ecosystems","authors":"Chao Guo, Wei Li, Adam G. Hansen, Shiqi Li, Jie Ke, Erik Jeppesen, Chuansong Liao, Jing Yuan, Tanglin Zhang, Chuanbo Guo, Jiashou Liu","doi":"10.1111/fwb.70136","DOIUrl":"https://doi.org/10.1111/fwb.70136","url":null,"abstract":"<div>\u0000 \u0000 <p>\u0000 \u0000 </p><ol>\u0000 \u0000 \u0000 <li>The proliferation of small-bodied fishes and their foraging effects within food webs can limit the growth of submerged macrophytes and degrade water quality in shallow lake ecosystems. The foraging habits of small-bodied fishes vary, and, therefore, ecosystem responses may differ depending on which species or feeding guild that dominates the fish community. Yet, species and feeding guild-specific foraging effects remain poorly understood.</li>\u0000 \u0000 \u0000 <li>Here, we used an experimental mesocosm to evaluate how water quality and submerged macrophytes respond to different species of small-bodied fishes, including omnivorous bitterling <i>Acheilognathus macropterus</i> (AMA), crucian carp <i>Carassius auratus</i> (CAU), sharpbelly <i>Hemiculter leucisculus</i> (HLE), zooplanktivorous thin sharpbelly <i>Toxabramis swinhonis</i> (TSW) and their mixes (1:1:1:1) (MIX).</li>\u0000 \u0000 \u0000 <li>Our results showed that the mean weekly total nitrogen, total phosphorus, turbidity, chlorophyll-<i>a</i> and trophic level index values were significantly higher in treatments with fish compared to fish-free controls during the experiment. At the end of the experiment, mean values for the number of submerged macrophyte shoots, leaf number, dry mass and the relative growth rate of shoots were significantly lower in the treatments with than without fish. In addition, mean values for leaf height, leaf width and the dry mass of submerged macrophytes in the TSW treatment were significantly greater than in the CAU, HLE and AMA treatments. Structural equation modelling revealed that small-bodied omnivorous fishes (i.e., crucian carp, sharpbelly and bitterling) affected submerged macrophyte growth more than zooplanktivorous fishes (i.e., thin sharpbelly), driven by their different foraging habits.</li>\u0000 \u0000 \u0000 <li>Our findings indicated that high abundances of small-bodied fishes have negative effects on water quality and the growth of submerged macrophytes in subtropical shallow lake ecosystems, but the effects differed with fish foraging guild. Control of overabundant small-bodied fishes (especially omnivorous fishes) may facilitate maintenance or effective restoration of submerged macrophytes and subtropical shallow lake ecosystem structure and function.</li>\u0000 </ol>\u0000 \u0000 </div>","PeriodicalId":12365,"journal":{"name":"Freshwater Biology","volume":"70 11","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145572605","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}
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