Pub Date : 2022-07-01DOI: 10.1080/02705060.2022.2092562
Yang Xu, Haihua Cheng, Z. Gu, Xilian Li, P. Shen, Qiang Gao
Abstract 16S rRNA gene sequencing was used to analyze the changes in the microbial community structure of Macrobrachium rosenbergii (M. rosenbergii) larvae and environmental water at different stages (0, 7, 14 and 21 days). The PICRUSt was used to precalculated the predicted genes and their functions. The Alpha and Beta diversity analysis showed that the abundance and uniformity of the flora of larvae and water samples were significantly different at four stages. At the phylum level, Proteobacteria, Planctomycetes, Firmicutes and Bacteroidetes were the dominant flora of larvae, while Proteobacteria, Bacteroidetes and Actinobacteria were the dominant flora of environmental water. But at the genus level, Raoultella and Blastopirellula were the main changes in larvae, and Dyadobacter, Flavobacterium and Pseudomonas were the main changes in environmental water. The gene function prediction analysis indicated that the amino acid metabolism, immune system, immune system disease, nervous system, sensory system and other pathways enriched in the different stages of larvae and environmental water were closely related to the breeding of M. rosenbergii. This research might provide theoretical basis and guidance for the high-quality breeding of M. rosenbergii. HIGHLIGHTS The abundance and uniformity of the flora of larvae and environmental water were significantly different at different stages. Several flora were found that related to the growth and development of larval. KEGG pathways enriched at different stages of larvae and environmental water were closely related to the breeding of larvae.
摘要采用16S rRNA基因测序技术，分析了罗氏沼虾(Macrobrachium rosenbergii, M. rosenbergii)不同生长阶段(0、7、14和21 d)幼虫和环境水体的微生物群落结构变化。PICRUSt用于预计算预测基因及其功能。α和β多样性分析表明，4个阶段幼虫和水样菌群的丰度和均匀性存在显著差异。在门水平上，幼虫的优势菌群为变形菌门、植物菌门、厚壁菌门和拟杆菌门，环境水体的优势菌群为变形菌门、拟杆菌门和放线菌门。但在属水平上，幼虫的变化以Raoultella和Blastopirellula为主，环境水体的变化以Dyadobacter、Flavobacterium和Pseudomonas为主。基因功能预测分析表明，不同阶段幼虫和环境水体中丰富的氨基酸代谢、免疫系统、免疫系统疾病、神经系统、感觉系统等途径与罗氏微孢子虫的繁殖密切相关。本研究可为罗氏沼虾的优质育种提供理论依据和指导。不同时期幼虫区系和环境水体的丰度和均匀性存在显著差异。发现了几种与幼虫生长发育有关的菌群。不同阶段的幼虫和环境水富集的KEGG通路与幼虫的繁殖密切相关。
{"title":"Study on microflora structure of Macrobrachium rosenbergii larvae and environmental water at different developmental stages","authors":"Yang Xu, Haihua Cheng, Z. Gu, Xilian Li, P. Shen, Qiang Gao","doi":"10.1080/02705060.2022.2092562","DOIUrl":"https://doi.org/10.1080/02705060.2022.2092562","url":null,"abstract":"Abstract 16S rRNA gene sequencing was used to analyze the changes in the microbial community structure of Macrobrachium rosenbergii (M. rosenbergii) larvae and environmental water at different stages (0, 7, 14 and 21 days). The PICRUSt was used to precalculated the predicted genes and their functions. The Alpha and Beta diversity analysis showed that the abundance and uniformity of the flora of larvae and water samples were significantly different at four stages. At the phylum level, Proteobacteria, Planctomycetes, Firmicutes and Bacteroidetes were the dominant flora of larvae, while Proteobacteria, Bacteroidetes and Actinobacteria were the dominant flora of environmental water. But at the genus level, Raoultella and Blastopirellula were the main changes in larvae, and Dyadobacter, Flavobacterium and Pseudomonas were the main changes in environmental water. The gene function prediction analysis indicated that the amino acid metabolism, immune system, immune system disease, nervous system, sensory system and other pathways enriched in the different stages of larvae and environmental water were closely related to the breeding of M. rosenbergii. This research might provide theoretical basis and guidance for the high-quality breeding of M. rosenbergii. HIGHLIGHTS The abundance and uniformity of the flora of larvae and environmental water were significantly different at different stages. Several flora were found that related to the growth and development of larval. KEGG pathways enriched at different stages of larvae and environmental water were closely related to the breeding of larvae.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"363 - 372"},"PeriodicalIF":1.3,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48669983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-06-17DOI: 10.1080/02705060.2022.2086181
Hai Li, Fan Yang, Ran Zhang, Shigang Liu, Zhijin Yang, Longshan Lin, S. Ye
Abstract Environmental DNA methods have emerged as a promising tool in fish diversity studies and fishery management in various aquatic ecosystems. However, eDNA metabarcoding of fish communities in small hydropower dam reservoirs has received limited attention. In this study, we tested whether eDNA metabarcoding was an appropriate approach for the characterization of fish communities and fishery stock assessment by comparing its results with combined capture-based fishing methods and hydroacoustic surveys, which involved species detection and abundance/biomass evaluation. Our results indicated that the species detection performance of eDNA metabarcoding was basically similar to that of traditional capture-based fishing gear. However, it was also noteworthy that the eDNA method failed to cover all species detected by capture-based method, although some additional species were found. Besides, although we observed a significant correlation between site occurrence and sequence abundance for fishes, an effort to quantitatively establish a correlation between eDNA sequence counts and fish abundance/biomass was unsuccessful. Therefore, our study suggested that eDNA metabarcoding was an important supplementary tool to traditional capture-based fishing methods for the investigation and biomonitoring of fish diversity in small hydropower dam reservoirs. Further studies on the mechanisms of eDNA production, persistence, transportation and degradation in reservoirs might facilitate the interpretation of fish abundance and biomass from eDNA data.
{"title":"Environmental DNA metabarcoding of fish communities in a small hydropower dam reservoir: a comparison between the eDNA approach and established fishing methods","authors":"Hai Li, Fan Yang, Ran Zhang, Shigang Liu, Zhijin Yang, Longshan Lin, S. Ye","doi":"10.1080/02705060.2022.2086181","DOIUrl":"https://doi.org/10.1080/02705060.2022.2086181","url":null,"abstract":"Abstract Environmental DNA methods have emerged as a promising tool in fish diversity studies and fishery management in various aquatic ecosystems. However, eDNA metabarcoding of fish communities in small hydropower dam reservoirs has received limited attention. In this study, we tested whether eDNA metabarcoding was an appropriate approach for the characterization of fish communities and fishery stock assessment by comparing its results with combined capture-based fishing methods and hydroacoustic surveys, which involved species detection and abundance/biomass evaluation. Our results indicated that the species detection performance of eDNA metabarcoding was basically similar to that of traditional capture-based fishing gear. However, it was also noteworthy that the eDNA method failed to cover all species detected by capture-based method, although some additional species were found. Besides, although we observed a significant correlation between site occurrence and sequence abundance for fishes, an effort to quantitatively establish a correlation between eDNA sequence counts and fish abundance/biomass was unsuccessful. Therefore, our study suggested that eDNA metabarcoding was an important supplementary tool to traditional capture-based fishing methods for the investigation and biomonitoring of fish diversity in small hydropower dam reservoirs. Further studies on the mechanisms of eDNA production, persistence, transportation and degradation in reservoirs might facilitate the interpretation of fish abundance and biomass from eDNA data.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"341 - 362"},"PeriodicalIF":1.3,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47673597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-06-10DOI: 10.1080/02705060.2022.2085199
J. Tiemann, Sarah A. Douglass, J. Sherwood, Andrew J. Stites, M. Dreslik
Abstract The Bigeye Chub (Hybopsis amblops) once inhabited streams and rivers in eastern and southeastern Illinois and was thought to be extirpated in the state by the 1970s. However, it was rediscovered in the 1990s from the Little Vermilion River. Today, H. amblops has become widespread and locally abundant in streams of the Wabash River drainage. Currently, little is known about the spawning and reproductive ecology of H. amblops. We conducted a study in the Salt Fork Vermilion River to determine the spawning schedule and microhabitats of H. amblops. Based upon near-weekly samples in May and June in 2019 and 2021, we determined H. amblops spawns in moderate water velocity over sandy gravel substrates when water temperatures are between 18–22 °C. Understanding such ecological traits is necessary for the continued success of H. amblops throughout its range.
{"title":"Spawning schedule of the imperiled Bigeye Chub (Hybopsis amblops) in Illinois","authors":"J. Tiemann, Sarah A. Douglass, J. Sherwood, Andrew J. Stites, M. Dreslik","doi":"10.1080/02705060.2022.2085199","DOIUrl":"https://doi.org/10.1080/02705060.2022.2085199","url":null,"abstract":"Abstract The Bigeye Chub (Hybopsis amblops) once inhabited streams and rivers in eastern and southeastern Illinois and was thought to be extirpated in the state by the 1970s. However, it was rediscovered in the 1990s from the Little Vermilion River. Today, H. amblops has become widespread and locally abundant in streams of the Wabash River drainage. Currently, little is known about the spawning and reproductive ecology of H. amblops. We conducted a study in the Salt Fork Vermilion River to determine the spawning schedule and microhabitats of H. amblops. Based upon near-weekly samples in May and June in 2019 and 2021, we determined H. amblops spawns in moderate water velocity over sandy gravel substrates when water temperatures are between 18–22 °C. Understanding such ecological traits is necessary for the continued success of H. amblops throughout its range.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"329 - 340"},"PeriodicalIF":1.3,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47603701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-05-27DOI: 10.1080/02705060.2022.2079740
Sophie C. Koster, Angelica J. Pytel, D. Houghton
Abstract While there is substantial support for the river continuum concept (RCC) using aquatic macroinvertebrates, nearly all of this support has come from studies using benthic specimen counts or relative biomass as the basis for comparing sites. We instead assessed the RCC using the ash-free dry mass (AFDM) of winged adult Ephemeroptera, Plecoptera, and Trichoptera (EPT) specimens. Insects were sampled at 13 sites along a 100 km 2nd–4th order reach of the Pine River in northern Lower Michigan using ultraviolet lights. Specimens were identified to the genus level and the AFDM of each functional feeding group (FFG) was calculated. Forty-two environmental and river morphological variables were tested for their ability to predict differences in EPT FFG biomass. A determined environmental gradient relating to increasing river size predicted over 80% of FFG biomass differences. Biomass of each individual FFG increased along the determined gradient, except for scrapers which decreased at the most downstream sites. The number of EPT genera also increased along the gradient. Our results were similar to those of previous studies, except that shredders nearly doubled in importance compared to RCC predictions, suggesting a greater ecological impact of shredders on forested streams than is typically reported.
{"title":"Testing continuity in a Michigan (USA) river using the organic biomass of adult Ephemeroptera, Plecoptera, and Trichoptera","authors":"Sophie C. Koster, Angelica J. Pytel, D. Houghton","doi":"10.1080/02705060.2022.2079740","DOIUrl":"https://doi.org/10.1080/02705060.2022.2079740","url":null,"abstract":"Abstract While there is substantial support for the river continuum concept (RCC) using aquatic macroinvertebrates, nearly all of this support has come from studies using benthic specimen counts or relative biomass as the basis for comparing sites. We instead assessed the RCC using the ash-free dry mass (AFDM) of winged adult Ephemeroptera, Plecoptera, and Trichoptera (EPT) specimens. Insects were sampled at 13 sites along a 100 km 2nd–4th order reach of the Pine River in northern Lower Michigan using ultraviolet lights. Specimens were identified to the genus level and the AFDM of each functional feeding group (FFG) was calculated. Forty-two environmental and river morphological variables were tested for their ability to predict differences in EPT FFG biomass. A determined environmental gradient relating to increasing river size predicted over 80% of FFG biomass differences. Biomass of each individual FFG increased along the determined gradient, except for scrapers which decreased at the most downstream sites. The number of EPT genera also increased along the gradient. Our results were similar to those of previous studies, except that shredders nearly doubled in importance compared to RCC predictions, suggesting a greater ecological impact of shredders on forested streams than is typically reported.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"299 - 311"},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48026716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-05-27DOI: 10.1080/02705060.2022.2083709
Deshou Cun, Yanran Dai, Yaocheng Fan, Fei-Hua Wang, W. Liang
Abstract To investigate the effect of submerged macrophytes on heterotrophic bacterioplankton communities in response to nutrient enrichment, we simulated mesocosms to test two factors, namely, the presence of Ceratophyllum demersum (L.) and the level of nutrients (slight and medium nutrient enrichment) under four possible system combinations for a duration of more than 3 months. The results show that C. demersum can affect the temporal dynamics of heterotrophic bacterioplankton density (HBD) and cause it to decrease. However, the effect of C. demersum on HBD was more pronounced under medium nutrient enrichment. The mean values of HBD in the treatment and control systems under slight nutrient enrichment were 1.30 × 105 cells mL−1 and 1.34 × 105 cells mL−1, respectively; whereas for medium nutrient enrichment, they were 1.78 × 105 cells mL−1 and 2.65 × 105 cells mL−1, respectively. The total nitrogen (TN) and total phosphorus (TP) concentrations were maintained throughout the experiment, and no significant differences were observed in the pH value, chlorophyll a (Chl. a) concentrations or dissolved organic carbon (DOC) levels between the systems with and without macrophytes, regardless of the nutrient level. Furthermore, linear mixed models revealed that environmental variables had a limited impact on HBD and that C. demersum had no significant direct effect on the environmental variables in the systems. A likely explanation is higher predation on bacterioplankton in the mesocosms, although allelopathic effects exerted by C. demersum cannot be excluded.
{"title":"Testing the effect of the submerged macrophyte Ceratophyllum demersum (L.) on heterotrophic bacterioplankton densities under different levels of nitrogen and phosphorus concentrations in shallow lake mesocosms","authors":"Deshou Cun, Yanran Dai, Yaocheng Fan, Fei-Hua Wang, W. Liang","doi":"10.1080/02705060.2022.2083709","DOIUrl":"https://doi.org/10.1080/02705060.2022.2083709","url":null,"abstract":"Abstract To investigate the effect of submerged macrophytes on heterotrophic bacterioplankton communities in response to nutrient enrichment, we simulated mesocosms to test two factors, namely, the presence of Ceratophyllum demersum (L.) and the level of nutrients (slight and medium nutrient enrichment) under four possible system combinations for a duration of more than 3 months. The results show that C. demersum can affect the temporal dynamics of heterotrophic bacterioplankton density (HBD) and cause it to decrease. However, the effect of C. demersum on HBD was more pronounced under medium nutrient enrichment. The mean values of HBD in the treatment and control systems under slight nutrient enrichment were 1.30 × 105 cells mL−1 and 1.34 × 105 cells mL−1, respectively; whereas for medium nutrient enrichment, they were 1.78 × 105 cells mL−1 and 2.65 × 105 cells mL−1, respectively. The total nitrogen (TN) and total phosphorus (TP) concentrations were maintained throughout the experiment, and no significant differences were observed in the pH value, chlorophyll a (Chl. a) concentrations or dissolved organic carbon (DOC) levels between the systems with and without macrophytes, regardless of the nutrient level. Furthermore, linear mixed models revealed that environmental variables had a limited impact on HBD and that C. demersum had no significant direct effect on the environmental variables in the systems. A likely explanation is higher predation on bacterioplankton in the mesocosms, although allelopathic effects exerted by C. demersum cannot be excluded.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"313 - 328"},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45457410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-05-27DOI: 10.1080/02705060.2022.2077463
Caixia Kang, Yurun Liu, Zhengong Tong
Abstract Water regime plays a determinant role in plant community development and patterns of plant zonation in wetlands. The waters located in the middle reach of the Yangtze River (China) have experienced a large decrease in wetland area from human activities for a long time, especially after the hydrological drought events in recent years. This outdoor study was conducted to clarify the morphological responses and reproductive strategy of Vallisneria spinulosa to water depth gradients (0.6 m, 1.0 m, 1.5 m) and to drawdown (down to 0.3 m). In static water, water depth of 1.0 m was the best condition for V. spinulosa to grow, manifested as high biomass of vegetative parts, tubers and sexual structures. However, V. spinulosa growing in water depth of 1.5 m was able to adapt to the decline in water depth in autumn, expressed as increased ramet number, stolon weight and belowground biomass. The low water depth of 0.6 m produced small plants with slight vegetative biomass and drawdown produced more tuber biomass. The drawdown caused a decline in vegetative ratio of V. spinulosa. Moreover, it caused an increase in clonal ratio at water levels of 1.5 m and 0.6 m, and a decline in sexual ratio at water levels of 1.5 m and 1.0 m. The results show that under the condition of relatively large fluctuations in water level, V. spinulosa will reduce the allocation of sexual biomass and increase the allocation of clonal biomass in order to cope with environmental changes so that it can proliferate better. Thus, water level changes have a great influence on the growth and reproduction of V. spinulosa.
{"title":"Effects of drawdown on growth and reproduction of submerged macrophyte Vallisneria spinulosa","authors":"Caixia Kang, Yurun Liu, Zhengong Tong","doi":"10.1080/02705060.2022.2077463","DOIUrl":"https://doi.org/10.1080/02705060.2022.2077463","url":null,"abstract":"Abstract Water regime plays a determinant role in plant community development and patterns of plant zonation in wetlands. The waters located in the middle reach of the Yangtze River (China) have experienced a large decrease in wetland area from human activities for a long time, especially after the hydrological drought events in recent years. This outdoor study was conducted to clarify the morphological responses and reproductive strategy of Vallisneria spinulosa to water depth gradients (0.6 m, 1.0 m, 1.5 m) and to drawdown (down to 0.3 m). In static water, water depth of 1.0 m was the best condition for V. spinulosa to grow, manifested as high biomass of vegetative parts, tubers and sexual structures. However, V. spinulosa growing in water depth of 1.5 m was able to adapt to the decline in water depth in autumn, expressed as increased ramet number, stolon weight and belowground biomass. The low water depth of 0.6 m produced small plants with slight vegetative biomass and drawdown produced more tuber biomass. The drawdown caused a decline in vegetative ratio of V. spinulosa. Moreover, it caused an increase in clonal ratio at water levels of 1.5 m and 0.6 m, and a decline in sexual ratio at water levels of 1.5 m and 1.0 m. The results show that under the condition of relatively large fluctuations in water level, V. spinulosa will reduce the allocation of sexual biomass and increase the allocation of clonal biomass in order to cope with environmental changes so that it can proliferate better. Thus, water level changes have a great influence on the growth and reproduction of V. spinulosa.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"287 - 297"},"PeriodicalIF":1.3,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49438924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-05-05DOI: 10.1080/02705060.2022.2060358
X. Bai, Zhongbao Zhao
Abstract Investigating the response of alien invasive plants to water level gradient in wetlands is important for developing strategies to prevent invasions by alien plants in these ecosystems. Controlled experiments were conducted to investigate the response of root morphology in the alien invasive plant Amaranthus retroflexus to water level gradient. The plants were planted in three water levels from low to high that resulted in drought, wet and flooded conditions. The results showed that biomass and allocation of A. retroflexus under flooded conditions were significantly lower than the other two treatments (p < .05). Root morphological parameters (root mean diameter, root length, root surface area and root volume) were maximum under wet condition, followed by dry and flooded conditions, and the differences were significant among the treatments (p < .05). Special root length and special root surface area were also significantly greater under wet condition than under dry condition (p < .05). The results indicate that water level gradient in wetlands affects root biomass and morphology of A. retroflexus, which has the highest growth potential under wet condition. The roots of the plant also exhibited plasticity to water level gradient. Therefore, maintaining a high water level in wetlands could restrict the growth of A. retroflexus and prevent its successful invasion. Moreover, a high water level is beneficial to the growth of wetland plants and further decreases the invasibility of wetland ecosystems.
{"title":"Short-time response in root morphology of alien invasive plant Amaranthus retroflexus to water level gradient","authors":"X. Bai, Zhongbao Zhao","doi":"10.1080/02705060.2022.2060358","DOIUrl":"https://doi.org/10.1080/02705060.2022.2060358","url":null,"abstract":"Abstract Investigating the response of alien invasive plants to water level gradient in wetlands is important for developing strategies to prevent invasions by alien plants in these ecosystems. Controlled experiments were conducted to investigate the response of root morphology in the alien invasive plant Amaranthus retroflexus to water level gradient. The plants were planted in three water levels from low to high that resulted in drought, wet and flooded conditions. The results showed that biomass and allocation of A. retroflexus under flooded conditions were significantly lower than the other two treatments (p < .05). Root morphological parameters (root mean diameter, root length, root surface area and root volume) were maximum under wet condition, followed by dry and flooded conditions, and the differences were significant among the treatments (p < .05). Special root length and special root surface area were also significantly greater under wet condition than under dry condition (p < .05). The results indicate that water level gradient in wetlands affects root biomass and morphology of A. retroflexus, which has the highest growth potential under wet condition. The roots of the plant also exhibited plasticity to water level gradient. Therefore, maintaining a high water level in wetlands could restrict the growth of A. retroflexus and prevent its successful invasion. Moreover, a high water level is beneficial to the growth of wetland plants and further decreases the invasibility of wetland ecosystems.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"259 - 268"},"PeriodicalIF":1.3,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44059098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-04-30DOI: 10.1080/02705060.2022.2072008
Andrya L Whitten, Jason A. DeBoer, Sabina Berry, Cassi J. Moody‐Carpenter, Benjamin J. Lubinski, N. Rude, J. Chick, Robert E. Colombo, G. Whitledge, J. Lamer
Abstract Channel catfish (Ictalurus puncatus) and freshwater drum (Aplodinotus grunniens) are two commercially and recreationally important species in large rivers of the Midwestern United States. Understanding their population demographics is essential to managing sustainable populations. In this study, we determined and compared the size structure, individual growth, and mortality estimates of channel catfish and freshwater drum among the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers to provide a current baseline for managing these populations. Results suggest that both fishes differed in size structure among rivers. Compared to all other rivers, the Mississippi River freshwater drum growth rate was the highest and the theoretical maximum length was the lowest, and the Ohio River annual mortality was lowest. Channel catfish growth did not differ among rivers, but annual mortality was significantly higher in the Mississippi River compared to the Wabash River. Given the importance of these two fishes, better understanding of their population demographics in these systems is essential to improving current and future fisheries management programs.
{"title":"Channel catfish and freshwater drum population demographics across four large Midwestern rivers","authors":"Andrya L Whitten, Jason A. DeBoer, Sabina Berry, Cassi J. Moody‐Carpenter, Benjamin J. Lubinski, N. Rude, J. Chick, Robert E. Colombo, G. Whitledge, J. Lamer","doi":"10.1080/02705060.2022.2072008","DOIUrl":"https://doi.org/10.1080/02705060.2022.2072008","url":null,"abstract":"Abstract Channel catfish (Ictalurus puncatus) and freshwater drum (Aplodinotus grunniens) are two commercially and recreationally important species in large rivers of the Midwestern United States. Understanding their population demographics is essential to managing sustainable populations. In this study, we determined and compared the size structure, individual growth, and mortality estimates of channel catfish and freshwater drum among the Illinois River and sections of the Mississippi, Ohio, and Wabash rivers to provide a current baseline for managing these populations. Results suggest that both fishes differed in size structure among rivers. Compared to all other rivers, the Mississippi River freshwater drum growth rate was the highest and the theoretical maximum length was the lowest, and the Ohio River annual mortality was lowest. Channel catfish growth did not differ among rivers, but annual mortality was significantly higher in the Mississippi River compared to the Wabash River. Given the importance of these two fishes, better understanding of their population demographics in these systems is essential to improving current and future fisheries management programs.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"269 - 285"},"PeriodicalIF":1.3,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48723002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-03-07DOI: 10.1080/02705060.2022.2034673
Jinghong Feng, Defu Liu, Y. Liu, Yi Li, Han Li, Lihui Chen, Jingwen Xiao, Jixin Liu, Jiawei Dong
Abstract In-stream structures, such as channel spanning logs and weirs, can enhance hyporheic exchange in streams. Hyporheic exchange is important for stream ecosystem function, and restoring this function is a goal of many stream restoration projects. However, studies on the connection between in-stream structure size, hydrogeologic setting, and hyporheic exchange remain inadequately characterized. In this study, we combined flume experiments and numerical simulations to systematically evaluate how in-stream structure and its hydrogeologic setting impacted the hyporheic vertical exchange flux, Q, the solute penetration depth, Dp, and the solute flux, QS, in the hyporheic zone. The results showed that stream water downwells into the riverbed upstream of the weir and upwells downstream. Exchange rates were greatest near the weir and decay with distance upstream and downstream. Model results indicated Q, Dp and QS had a positive exponential relationship with the weir height, h, the flow velocity, u, and the sediment intrinsic permeability, k. While model results indicated that u was the most important factor determining Q, Dp and QS, followed by h, while only h reached a certain value, the hyporheic exchange would increase with the height and vice versa. Hyporheic exchange generally was sensitive to changes in k, only the magnitude of k varied from 10−8–10−10m2. This finding suggests that a rethinking of the currently applied restoration techniques is required to better consider in-stream structure size, hydrological conditions and natural substratum dynamics in river restoration.
{"title":"Hyporheic exchange due to in-stream geomorphic structures","authors":"Jinghong Feng, Defu Liu, Y. Liu, Yi Li, Han Li, Lihui Chen, Jingwen Xiao, Jixin Liu, Jiawei Dong","doi":"10.1080/02705060.2022.2034673","DOIUrl":"https://doi.org/10.1080/02705060.2022.2034673","url":null,"abstract":"Abstract In-stream structures, such as channel spanning logs and weirs, can enhance hyporheic exchange in streams. Hyporheic exchange is important for stream ecosystem function, and restoring this function is a goal of many stream restoration projects. However, studies on the connection between in-stream structure size, hydrogeologic setting, and hyporheic exchange remain inadequately characterized. In this study, we combined flume experiments and numerical simulations to systematically evaluate how in-stream structure and its hydrogeologic setting impacted the hyporheic vertical exchange flux, Q, the solute penetration depth, Dp, and the solute flux, QS, in the hyporheic zone. The results showed that stream water downwells into the riverbed upstream of the weir and upwells downstream. Exchange rates were greatest near the weir and decay with distance upstream and downstream. Model results indicated Q, Dp and QS had a positive exponential relationship with the weir height, h, the flow velocity, u, and the sediment intrinsic permeability, k. While model results indicated that u was the most important factor determining Q, Dp and QS, followed by h, while only h reached a certain value, the hyporheic exchange would increase with the height and vice versa. Hyporheic exchange generally was sensitive to changes in k, only the magnitude of k varied from 10−8–10−10m2. This finding suggests that a rethinking of the currently applied restoration techniques is required to better consider in-stream structure size, hydrological conditions and natural substratum dynamics in river restoration.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"221 - 241"},"PeriodicalIF":1.3,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45489368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2022-02-28DOI: 10.1080/02705060.2022.2034674
G. Vagenas, M. Stoumboudi, O. Petriki, A. Andriopoulou, Ioanna Tsionki, P. Karachle
Abstract The diet of five freshwater fish species of Lake Trichonis, the largest natural lake of Greece, was studied. Specifically, the studied species were Atherina boyeri, Luciobarbus albanicus, Leucos panosi, Scardinius acarnanicus and Tropidophoxinellus hellenicus. The diet analysis was based on stomach content analysis of seasonal samples collected during 2019 by experimental Nordic multimesh gillnets. Additionally, trophic indices were estimated (Shannon-Wiener, Levins’, Schoener, Trophic level) so as to investigate each species’ feeding diversity, trophic niche breadth, trophic level as well as their trophic competition and overlap. Moreover, the annual and the seasonal relative condition factor was estimated. The diet analysis indicated a tendency of the studied species to omnivorous feeding strategy and a seasonal fluctuation in their diet composition. In addition, the estimated trophic indices revealed similar feeding behavior and significant diet overlap between species, suggesting narrow partitioning of the food resources. However, the relative condition factor ranged between 0.973 and 1.041, indicating a state of wellbeing for the fish species and possibly sufficient food availability.
{"title":"Dietary patterns of five freshwater fish species in a large Mediterranean lake","authors":"G. Vagenas, M. Stoumboudi, O. Petriki, A. Andriopoulou, Ioanna Tsionki, P. Karachle","doi":"10.1080/02705060.2022.2034674","DOIUrl":"https://doi.org/10.1080/02705060.2022.2034674","url":null,"abstract":"Abstract The diet of five freshwater fish species of Lake Trichonis, the largest natural lake of Greece, was studied. Specifically, the studied species were Atherina boyeri, Luciobarbus albanicus, Leucos panosi, Scardinius acarnanicus and Tropidophoxinellus hellenicus. The diet analysis was based on stomach content analysis of seasonal samples collected during 2019 by experimental Nordic multimesh gillnets. Additionally, trophic indices were estimated (Shannon-Wiener, Levins’, Schoener, Trophic level) so as to investigate each species’ feeding diversity, trophic niche breadth, trophic level as well as their trophic competition and overlap. Moreover, the annual and the seasonal relative condition factor was estimated. The diet analysis indicated a tendency of the studied species to omnivorous feeding strategy and a seasonal fluctuation in their diet composition. In addition, the estimated trophic indices revealed similar feeding behavior and significant diet overlap between species, suggesting narrow partitioning of the food resources. However, the relative condition factor ranged between 0.973 and 1.041, indicating a state of wellbeing for the fish species and possibly sufficient food availability.","PeriodicalId":54830,"journal":{"name":"Journal of Freshwater Ecology","volume":"37 1","pages":"203 - 220"},"PeriodicalIF":1.3,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49375013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
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