Abstract: Aim Our study was carried out to develop a multimetric index suitable for urban wadeable streams in Sorocaba, a large-sized city from the Atlantic rainforest in south-eastern Brazil. Methods Twenty-seven stream stretches were selected for environmental and fish evaluation. Twenty ecological metrics were tested over an environmental gradient between the reference and degraded stretches. Candidate metrics were screened for range, responsiveness, and redundancy. We calculated a multimetric fish index (MFI) subdivided into five quality classes: reference ≥ 0.8, 0.6 ≤ good < 0.8, 0.4 ≤ moderate < 0.6, 0.2 ≤ poor < 0.4, and bad < 0.2. Results Four metrics were adequate for discriminating higher biotic quality from degraded stretches. Five stream stretches (18%) were classified as a reference or good, and 16 (60%) were poor or bad. Three reference stretches could be used for a hydromorphological restoration programme. Conclusion Our results indicated that biological integrity was altered, which was indicative of severe environmental degradation. Our study results may be useful for a management and restoration project of the Sorocaba/Médio Tietê hydrographic basin.
{"title":"A stream multimetric fish index in a large-sized city in south-eastern Brazil","authors":"Guilherme Raphael Camargo Arcanjo Silva, M. Cetra","doi":"10.1590/S2179-975X5020","DOIUrl":"https://doi.org/10.1590/S2179-975X5020","url":null,"abstract":"Abstract: Aim Our study was carried out to develop a multimetric index suitable for urban wadeable streams in Sorocaba, a large-sized city from the Atlantic rainforest in south-eastern Brazil. Methods Twenty-seven stream stretches were selected for environmental and fish evaluation. Twenty ecological metrics were tested over an environmental gradient between the reference and degraded stretches. Candidate metrics were screened for range, responsiveness, and redundancy. We calculated a multimetric fish index (MFI) subdivided into five quality classes: reference ≥ 0.8, 0.6 ≤ good < 0.8, 0.4 ≤ moderate < 0.6, 0.2 ≤ poor < 0.4, and bad < 0.2. Results Four metrics were adequate for discriminating higher biotic quality from degraded stretches. Five stream stretches (18%) were classified as a reference or good, and 16 (60%) were poor or bad. Three reference stretches could be used for a hydromorphological restoration programme. Conclusion Our results indicated that biological integrity was altered, which was indicative of severe environmental degradation. Our study results may be useful for a management and restoration project of the Sorocaba/Médio Tietê hydrographic basin.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67866188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/s2179-975x100200201
{"title":"Erratum: Editorial: Freshwater sustainability and aquatic ecology in a fast-changing world","authors":"","doi":"10.1590/s2179-975x100200201","DOIUrl":"https://doi.org/10.1590/s2179-975x100200201","url":null,"abstract":"","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67822557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fernanda Monicelli, K. P. V. Cunha, F. Araújo, V. Becker
Abstract: Aim The aim of the present study was to evaluate the potential soluble reactive phosphorus (SRP) sorption of three natural P adsorbents (Luvisol, Planosol, and Scheelite tailing) from Brazil’s semiarid region. Methods The adsorption tests were done under pH 8 conditions with the natural adsorbents and Lanthanum-Modified Bentonite (LMB). The effect of humic substances on SRP sorption was also tested. For this, Luvisol and Planosol were incinerated to reduce their humic components, and new adsorption tests were done. The effect of adsorbents on water pH was also evaluated. Results The SRP sorption potential of the natural adsorbents was high at pH 8. Of the natural adsorbents, Luvisol achieved the highest maximum SRP adsorption capacity (Q) of 17.5 mg g-1, followed by Scheelite tailing (8.3 mg g-1) and Planosol (7.7 mg g-1). Scheelite tailing, Planosol and LMB increased the pH of the water. After treatment to reduce humic substances, Planosol showed a Q of 22.3 mg g-1 while Luvisol produced 11.1mg g-1. Reducing the amount of humic substances potentiated the sorption process in the Planosol. However, the isotherms of untreated Luvisol and treated Planosol have not reached equilibrium and therefore may be overestimated. Conclusions The precipitation process was probably the main sorption mechanism, being more expressive than adsorption. Scheelite tailing was the most promising material for eutrophic environments because it is alkaline, calcium-rich, and this capacity will probably remain high under anoxic conditions. It also has a small amount of organic matter and, consequently, contains less humic substances. The quality of the clay present in natural adsorbents was more important than quantity in the sorption process.
{"title":"Phosphorus sorption potential of natural adsorbent materials from a Brazil semiarid region to control eutrophication","authors":"Fernanda Monicelli, K. P. V. Cunha, F. Araújo, V. Becker","doi":"10.1590/s2179-975x2621","DOIUrl":"https://doi.org/10.1590/s2179-975x2621","url":null,"abstract":"Abstract: Aim The aim of the present study was to evaluate the potential soluble reactive phosphorus (SRP) sorption of three natural P adsorbents (Luvisol, Planosol, and Scheelite tailing) from Brazil’s semiarid region. Methods The adsorption tests were done under pH 8 conditions with the natural adsorbents and Lanthanum-Modified Bentonite (LMB). The effect of humic substances on SRP sorption was also tested. For this, Luvisol and Planosol were incinerated to reduce their humic components, and new adsorption tests were done. The effect of adsorbents on water pH was also evaluated. Results The SRP sorption potential of the natural adsorbents was high at pH 8. Of the natural adsorbents, Luvisol achieved the highest maximum SRP adsorption capacity (Q) of 17.5 mg g-1, followed by Scheelite tailing (8.3 mg g-1) and Planosol (7.7 mg g-1). Scheelite tailing, Planosol and LMB increased the pH of the water. After treatment to reduce humic substances, Planosol showed a Q of 22.3 mg g-1 while Luvisol produced 11.1mg g-1. Reducing the amount of humic substances potentiated the sorption process in the Planosol. However, the isotherms of untreated Luvisol and treated Planosol have not reached equilibrium and therefore may be overestimated. Conclusions The precipitation process was probably the main sorption mechanism, being more expressive than adsorption. Scheelite tailing was the most promising material for eutrophic environments because it is alkaline, calcium-rich, and this capacity will probably remain high under anoxic conditions. It also has a small amount of organic matter and, consequently, contains less humic substances. The quality of the clay present in natural adsorbents was more important than quantity in the sorption process.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67853403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafaela Shizuko Yamashita Kimura, E. Brambilla, João Felipe Denys Pereira, M. Nogueira
Abstract: Aim This study verified if the macrophyte banks found in two reservoirs of small hydroelectric plants (SHPs) have a functional ecological role for the initial development of ichthyofauna. Additionally, we compared the differences in the structure of the fish assemblages along each reservoir compartment and between reservoirs. Methods Sampling was performed in March 2018, in lotic, intermediate, and lentic compartments of Palmeiras and Retiro reservoirs, Sapucaí-Mirim River (SP). Three distinct macrophyte banks in each stretch (triplicates), considering the most representative in terms of composition (recurrency/dominance), were sampled, resulting in 18 samples (nine per reservoir). For fish collection we used a sieve of 1 m2 of area, mesh size of 1 mm, which was manually hauled, from the boat, in the marginal aquatic vegetation (three hauls per sample). Simultaneously, we measured basic limnological parameters with a Horiba U-52 water probe, adjacent to the banks. Results The presence of juveniles of all fish orders found in the river, Characiformes, Siluriformes, Synbranchiformes, Gymnotiformes and Cichliformes, demonstrates that, at least in certain moment of their development cycle, the macrophyte banks are used by species with different ecological requirements. It was observed significant statistical differences in the structure of the ichthyofauna along the longitudinal axes of the reservoirs, but not between reservoirs. The same was seen for the limnological data (PCA). Conclusions The macrophyte banks found in the SHPs reservoirs have a potential role as nurseries for the local ichthyofauna, mainly, but not exclusively, for sedentary species and with parental care. This association is ecologically relevant, given the absence of typical lateral habitats for the initial development of the fish fauna. Additionally, despite the reservoirs small size, spatial organization was also important for the assemblage’s structure, with differences in terms of composition, size and development stages along the distinct sampling stretches.
摘要:目的验证两个小型水电站水库中发现的大型植物库是否对鱼系动物的初始发育具有功能性生态作用。此外，我们还比较了每个水库隔室和水库之间鱼类组合结构的差异。方法于2018年3月在Sapucaí-Mirim River (SP) Palmeiras和Retiro水库的水中、中间和水中进行采样。考虑到在组成(复发性/优势性)方面最具代表性，在每个伸展(三复)中对三个不同的大型植物库进行了采样，结果得到18个样本(每个水库9个)。收集鱼类时，我们使用1平方米面积的筛子，网目尺寸为1毫米，在边缘水生植被中手工从船上拖出(每个样本拖三次)。同时，我们在靠近河岸的地方用堀场U-52水探头测量了基本的湖泊参数。结果该河流中所有鱼类目(特征目、志留目、合鳃目、裸子目和鱼形目)幼鱼的存在表明，至少在其发育周期的某个时刻，大型植物滩被不同生态需求的物种所利用。在水库的纵轴上观察到鱼类的结构有显著的统计学差异，但在水库之间没有统计学差异。湖沼学数据(PCA)也是如此。结论SHPs水库中发现的大型植物库具有潜在的哺育作用，主要但不限于定居物种和亲代照顾。考虑到鱼类区系最初发育缺乏典型的横向栖息地，这种关联具有生态学意义。此外，尽管储层规模较小，但空间组织对组合结构也很重要，在不同采样段的组成、大小和发育阶段都存在差异。
{"title":"Macrophytes banks as potential fish nursery areas in small hydropower reservoirs","authors":"Rafaela Shizuko Yamashita Kimura, E. Brambilla, João Felipe Denys Pereira, M. Nogueira","doi":"10.1590/s2179-975x1621","DOIUrl":"https://doi.org/10.1590/s2179-975x1621","url":null,"abstract":"Abstract: Aim This study verified if the macrophyte banks found in two reservoirs of small hydroelectric plants (SHPs) have a functional ecological role for the initial development of ichthyofauna. Additionally, we compared the differences in the structure of the fish assemblages along each reservoir compartment and between reservoirs. Methods Sampling was performed in March 2018, in lotic, intermediate, and lentic compartments of Palmeiras and Retiro reservoirs, Sapucaí-Mirim River (SP). Three distinct macrophyte banks in each stretch (triplicates), considering the most representative in terms of composition (recurrency/dominance), were sampled, resulting in 18 samples (nine per reservoir). For fish collection we used a sieve of 1 m2 of area, mesh size of 1 mm, which was manually hauled, from the boat, in the marginal aquatic vegetation (three hauls per sample). Simultaneously, we measured basic limnological parameters with a Horiba U-52 water probe, adjacent to the banks. Results The presence of juveniles of all fish orders found in the river, Characiformes, Siluriformes, Synbranchiformes, Gymnotiformes and Cichliformes, demonstrates that, at least in certain moment of their development cycle, the macrophyte banks are used by species with different ecological requirements. It was observed significant statistical differences in the structure of the ichthyofauna along the longitudinal axes of the reservoirs, but not between reservoirs. The same was seen for the limnological data (PCA). Conclusions The macrophyte banks found in the SHPs reservoirs have a potential role as nurseries for the local ichthyofauna, mainly, but not exclusively, for sedentary species and with parental care. This association is ecologically relevant, given the absence of typical lateral habitats for the initial development of the fish fauna. Additionally, despite the reservoirs small size, spatial organization was also important for the assemblage’s structure, with differences in terms of composition, size and development stages along the distinct sampling stretches.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67827025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Aim Copper is an essential nutrient for the phytoplankton, but it can also act as a toxic agent, depending on its concentration. Considering the continuous increase of this metal in the natural aquatic ecosystems, understanding its actions in co-cultivation scenarios is of great relevance. Experiments with the combination of different species resemble more accurately the natural conditions, in contrast of results obtained in single-species tests, which cannot be directly used to describe observed effects on the environment. Methods Therefore, growth parameters were investigated and compared on the co-cultivation of Chlorella sorokiniana and Kirchneriella obesa and their separate cultures exposed to three different free copper concentrations (control 6x10-9, intermediate 2x10-7 and high 1.5x10-6 mol.L-1 Cu2+). Results C. sorokiniana registered more cells in the control of the unialgal culture while K. obesa had higher cell density in the control of the co-cultivation. Growth rates decreased with the increment of copper in the unialgal conditions. However, both species maintained a high growth rate in the co-cultivation intermediate copper concentrations. Biovolume varied despite the cultivation method, being strongly related to the metal’s concentration. The maximum photosynthetic efficiency decreased in higher copper. Conclusions According to the results observed, no competitive exclusion occurred and both species were affected by copper in unialgal and co-cultivation conditions, with K. obesa being favored by the co-cultivation, which seems to have an attenuation effect on copper toxicity until intermediate concentrations. Ecologically, the results suggest that communities deal better with the toxic effects caused by intermediate copper concentrations than single-species cultures.
{"title":"Growth dynamic on a co-cultivation of two Chlorophyta microalgae exposed to copper","authors":"R. B. Dextro","doi":"10.1590/s2179-975x0420","DOIUrl":"https://doi.org/10.1590/s2179-975x0420","url":null,"abstract":"Abstract: Aim Copper is an essential nutrient for the phytoplankton, but it can also act as a toxic agent, depending on its concentration. Considering the continuous increase of this metal in the natural aquatic ecosystems, understanding its actions in co-cultivation scenarios is of great relevance. Experiments with the combination of different species resemble more accurately the natural conditions, in contrast of results obtained in single-species tests, which cannot be directly used to describe observed effects on the environment. Methods Therefore, growth parameters were investigated and compared on the co-cultivation of Chlorella sorokiniana and Kirchneriella obesa and their separate cultures exposed to three different free copper concentrations (control 6x10-9, intermediate 2x10-7 and high 1.5x10-6 mol.L-1 Cu2+). Results C. sorokiniana registered more cells in the control of the unialgal culture while K. obesa had higher cell density in the control of the co-cultivation. Growth rates decreased with the increment of copper in the unialgal conditions. However, both species maintained a high growth rate in the co-cultivation intermediate copper concentrations. Biovolume varied despite the cultivation method, being strongly related to the metal’s concentration. The maximum photosynthetic efficiency decreased in higher copper. Conclusions According to the results observed, no competitive exclusion occurred and both species were affected by copper in unialgal and co-cultivation conditions, with K. obesa being favored by the co-cultivation, which seems to have an attenuation effect on copper toxicity until intermediate concentrations. Ecologically, the results suggest that communities deal better with the toxic effects caused by intermediate copper concentrations than single-species cultures.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67821492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Klivia Rilavia Paiva da Silva, J. E. L. Barbosa, L. Santana, L. Barbosa
Abstract: Aim The study analyzed the potential use of the phytoplankton functional groups as an environmental bioindicator in aquatic ecosystems of Brazilian semiarid region. Methods Using data collected over five years of a natural lagoon and two reservoirs, we evaluate the relationship between functional groups and environmental conditions through the multivariate approach. The Q index was applied to assess ecological status in these ecosystems. Results In Panati, the temporary and natural lagoon, the partial habitat desiccation and presence of macrophytes reflected in the less nutrients concentrations and phytoplankton composition, with high biomass of coccoids Chlorophyceae, diatoms and desmids (functional groups J, MP and N, respectively). Taperoá and Soledade reservoirs presented high cyanobacteria contribution, however the biomass and contribution of cyanobacteria in Taperoá (SN, S1) were lower than in Soledade. In this reservoir, cyanobacteria were more abundant, alternating in dominance (LO, M, LM, SN, S1). According to tendencies revealed by Redundancy Analysis (RDA), the main driving abiotic factors on the phytoplankton functional groups were pH, nutrients and light availability. As expected, phytoplankton composition directly influenced the Q index result, showing mostly bad to tolerable conditions in Soledade, medium to good in Taperoá and good to excellent in Panati. Conclusions The Q index was a good tool to assess the water quality and ecological status in aquatic ecosystems from the Brazilian semiarid region, reflecting the influence of natural control mechanisms on the harmful cyanobacteria blooms in temporary ecosystems.
摘要:目的分析浮游植物功能群在巴西半干旱区水生生态系统中作为环境生物指标的潜力。方法利用一个天然泻湖和两个水库5年的数据，通过多变量方法评估功能基团与环境条件的关系。采用Q指数对这些生态系统的生态状况进行了评价。结果Panati临时泻湖和天然泻湖的生境部分干燥和大型植物的存在，反映在营养物质浓度和浮游植物组成上较低，球藻、绿藻、硅藻和浮游植物(官能团分别为J、MP和N)的生物量较高。tapero和Soledade水库蓝藻贡献均较高，但tapero (SN, S1)的生物量和蓝藻贡献均低于Soledade。在该储层中，蓝藻更为丰富，且优势交替(LO, M, LM, SN, S1)。根据冗余分析(RDA)的趋势，浮游植物功能群的主要驱动非生物因子是pH、养分和光有效性。正如预期的那样，浮游植物组成直接影响Q指数结果，在Soledade中表现为差到尚可，在tapero中表现为中等到良好，在Panati中表现为良好到优秀。结论Q指数是评价巴西半干旱区水生生态系统水质和生态状况的良好工具，反映了自然调控机制对临时生态系统中有害蓝藻华的影响。
{"title":"Phytoplankton functional groups in shallow aquatic ecosystems from the semiarid region of Brazil","authors":"Klivia Rilavia Paiva da Silva, J. E. L. Barbosa, L. Santana, L. Barbosa","doi":"10.1590/s2179-975x10320","DOIUrl":"https://doi.org/10.1590/s2179-975x10320","url":null,"abstract":"Abstract: Aim The study analyzed the potential use of the phytoplankton functional groups as an environmental bioindicator in aquatic ecosystems of Brazilian semiarid region. Methods Using data collected over five years of a natural lagoon and two reservoirs, we evaluate the relationship between functional groups and environmental conditions through the multivariate approach. The Q index was applied to assess ecological status in these ecosystems. Results In Panati, the temporary and natural lagoon, the partial habitat desiccation and presence of macrophytes reflected in the less nutrients concentrations and phytoplankton composition, with high biomass of coccoids Chlorophyceae, diatoms and desmids (functional groups J, MP and N, respectively). Taperoá and Soledade reservoirs presented high cyanobacteria contribution, however the biomass and contribution of cyanobacteria in Taperoá (SN, S1) were lower than in Soledade. In this reservoir, cyanobacteria were more abundant, alternating in dominance (LO, M, LM, SN, S1). According to tendencies revealed by Redundancy Analysis (RDA), the main driving abiotic factors on the phytoplankton functional groups were pH, nutrients and light availability. As expected, phytoplankton composition directly influenced the Q index result, showing mostly bad to tolerable conditions in Soledade, medium to good in Taperoá and good to excellent in Panati. Conclusions The Q index was a good tool to assess the water quality and ecological status in aquatic ecosystems from the Brazilian semiarid region, reflecting the influence of natural control mechanisms on the harmful cyanobacteria blooms in temporary ecosystems.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67823894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Santos, E. D. de Castro, V. Duarte, M. P. Pereira, F. F. Corrêa, F. J. Pereira
Abstract Aim The capacity of macrophytes to colonize large areas is often referred to as dependent of the investment in root system and its capacity to uptake nutrients. This work aimed to evaluate the phosphorus (P) effects on the root growth and anatomy as well as its capacity to uptake this nutrient by the aquatic macrophyte Typha domingensis. Methods Plants were grown for 60 days in nutrient solution containing 0, 0.2, 0.4, 0.6 or 0.8 mM of phosphorus. At the end of the experiment, the root length and P root content as well as the root anatomy at the maturation and meristematic zones were evaluated. Results Higher P concentrations increased the uptake of this nutrient and plant dry mass. However, the root length was reduced by higher phosphorus levels. In addition, P increased the proportion of the root cap while reduced the proportion of the procambium at the meristematic zone. Higher phosphorus concentrations reduced the xylem vessel diameter and the proportion of the vascular cylinder at the maturation zone, whereas increased phloem proportion was observed under this condition. Furthermore, higher phosphorus levels reduced the endodermis and exodermis thickness as well as the aerenchyma proportion. Conclusions Therefore, the T. domingensis P requirement is fulfilled at 0.4 mM of this nutrient and hypertrophic conditions promote the development of unfavorable root anatomical traits and reduction of the root growth.
{"title":"Root growth and anatomy of Typha domingensis Pers. related to phosphorus availability","authors":"J. Santos, E. D. de Castro, V. Duarte, M. P. Pereira, F. F. Corrêa, F. J. Pereira","doi":"10.1590/s2179-975x2120","DOIUrl":"https://doi.org/10.1590/s2179-975x2120","url":null,"abstract":"Abstract Aim The capacity of macrophytes to colonize large areas is often referred to as dependent of the investment in root system and its capacity to uptake nutrients. This work aimed to evaluate the phosphorus (P) effects on the root growth and anatomy as well as its capacity to uptake this nutrient by the aquatic macrophyte Typha domingensis. Methods Plants were grown for 60 days in nutrient solution containing 0, 0.2, 0.4, 0.6 or 0.8 mM of phosphorus. At the end of the experiment, the root length and P root content as well as the root anatomy at the maturation and meristematic zones were evaluated. Results Higher P concentrations increased the uptake of this nutrient and plant dry mass. However, the root length was reduced by higher phosphorus levels. In addition, P increased the proportion of the root cap while reduced the proportion of the procambium at the meristematic zone. Higher phosphorus concentrations reduced the xylem vessel diameter and the proportion of the vascular cylinder at the maturation zone, whereas increased phloem proportion was observed under this condition. Furthermore, higher phosphorus levels reduced the endodermis and exodermis thickness as well as the aerenchyma proportion. Conclusions Therefore, the T. domingensis P requirement is fulfilled at 0.4 mM of this nutrient and hypertrophic conditions promote the development of unfavorable root anatomical traits and reduction of the root growth.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67851431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Macêdo, Lorena Pinheiro‐Silva, Adriana Lamanna Puga, Gabriel Klippel, B. Kozlowsky-Suzuki, O. Rocha, C. Branco
Abstract: Aim In this study, the effect of preservation time on total body length and dry weight of adult specimens of the neotropical cladoceran Ceriodaphnia silvestrii preserved with 4% formalin solution were examined. Methods The relationship between these variables was examined under increasing gradual time effects (i.e. 7, 30, and 60 days) after preservation using linear models and analysis of variance. Results Total body length did not statistically differ between fresh and preserved cladocerans at any preservation time, whereas dry weight was drastically reduced with increasing preservation time, with 15, 47 and 57% weight losses. Length-weight relationships were significantly and positively related in all treatments, though higher values of slope were found for fresh and 7 days samples. Conclusions We highlight that, for Ceriodaphnia silvestrii, the use of the formalin solution as a preservation fixative is not adequate when the major interest is biomass estimation. Also, we recommend that dry weight estimations from preserved samples should be done as soon as possible. Finally, considering the preservation losses and intra-specific composition of organisms, the application of correction factors is advised since preserved samples are important in the evaluation of long-term changes of biological communities.
{"title":"Effects of formaldehyde preservation time on the length-weight relationship of the ubiquitous neotropical cladoceran Ceriodaphnia silvestrii","authors":"R. Macêdo, Lorena Pinheiro‐Silva, Adriana Lamanna Puga, Gabriel Klippel, B. Kozlowsky-Suzuki, O. Rocha, C. Branco","doi":"10.1590/s2179-975x3321","DOIUrl":"https://doi.org/10.1590/s2179-975x3321","url":null,"abstract":"Abstract: Aim In this study, the effect of preservation time on total body length and dry weight of adult specimens of the neotropical cladoceran Ceriodaphnia silvestrii preserved with 4% formalin solution were examined. Methods The relationship between these variables was examined under increasing gradual time effects (i.e. 7, 30, and 60 days) after preservation using linear models and analysis of variance. Results Total body length did not statistically differ between fresh and preserved cladocerans at any preservation time, whereas dry weight was drastically reduced with increasing preservation time, with 15, 47 and 57% weight losses. Length-weight relationships were significantly and positively related in all treatments, though higher values of slope were found for fresh and 7 days samples. Conclusions We highlight that, for Ceriodaphnia silvestrii, the use of the formalin solution as a preservation fixative is not adequate when the major interest is biomass estimation. Also, we recommend that dry weight estimations from preserved samples should be done as soon as possible. Finally, considering the preservation losses and intra-specific composition of organisms, the application of correction factors is advised since preserved samples are important in the evaluation of long-term changes of biological communities.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67858659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ignacio Masson, J. G. Castelain, Sabrina Dubny, Natalia Othax, F. Peluso
Abstract: Aim Freshwater communities respond to abiotic and biotic changes in the environment, and are widely used as indicators of environmental integrity. Fish have been one of the most used biological groups for this purpose. The Del Azul stream located in the pampean region of Argentina has been monitored using a physicochemical approach with this monitoring being sporadic due to economic and operational constraints associated with the chemical analyses. In this paper we developed an Index of Biotic Integrity for the Del Azul stream (IBIA) based on Karr´s Index of Biotic Integrity as an alternative. Methods We computed two existent physicochemical indexes for comparison, one of them is the NSF-WQI and the other one is a local index referred to as Water Quality Index for Del Azul Stream and based on the former. Results The three indexes followed similar trends along the examined reaches, showing good conditions in the upper basin, poor conditions just downstream of the urban area and a recovery state further downstream in the basin. Conclusions Since the IBIA followed the same patterns as the physicochemical indexes, has a lower implementation cost and it is simpler to apply, we promote it as an alternative to the traditional physicochemical water quality monitoring for pampean streams.
{"title":"Index of Biotic Integrity based on fish assemblages for pampean streams and its implementation along the Del Azul stream (Buenos Aires province, Argentina)","authors":"Ignacio Masson, J. G. Castelain, Sabrina Dubny, Natalia Othax, F. Peluso","doi":"10.1590/S2179-975X8220","DOIUrl":"https://doi.org/10.1590/S2179-975X8220","url":null,"abstract":"Abstract: Aim Freshwater communities respond to abiotic and biotic changes in the environment, and are widely used as indicators of environmental integrity. Fish have been one of the most used biological groups for this purpose. The Del Azul stream located in the pampean region of Argentina has been monitored using a physicochemical approach with this monitoring being sporadic due to economic and operational constraints associated with the chemical analyses. In this paper we developed an Index of Biotic Integrity for the Del Azul stream (IBIA) based on Karr´s Index of Biotic Integrity as an alternative. Methods We computed two existent physicochemical indexes for comparison, one of them is the NSF-WQI and the other one is a local index referred to as Water Quality Index for Del Azul Stream and based on the former. Results The three indexes followed similar trends along the examined reaches, showing good conditions in the upper basin, poor conditions just downstream of the urban area and a recovery state further downstream in the basin. Conclusions Since the IBIA followed the same patterns as the physicochemical indexes, has a lower implementation cost and it is simpler to apply, we promote it as an alternative to the traditional physicochemical water quality monitoring for pampean streams.","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67871546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ERRATUM: Zooplankton trajectory before, during and after a hydropower dam construction","authors":"","doi":"10.1590/s2179-975x95190","DOIUrl":"https://doi.org/10.1590/s2179-975x95190","url":null,"abstract":"","PeriodicalId":38854,"journal":{"name":"Acta Limnologica Brasiliensia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67873025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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