Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.330
Filtrar
1.
Braz. j. biol ; 84: e248656, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345542

RESUMO

Abstract Several species of Cichla successfully colonized lakes and reservoirs of Brazil, since the 1960's, causing serious damage to local wildlife. In this study, 135 peacock bass were collected in a reservoir complex in order to identify if they represented a single dominant species or multiple ones, as several Cichla species have been reported in the basin. Specimens were identified by color pattern, morphometric and meristic data, and using mitochondrial markers COI, 16S rDNA and Control Region (CR). Overlapping morphological data and similar coloration patterns prevented their identification using the taxonomic keys to species identification available in the literature. However, Bayesian and maximum likelihood from sequencing data demonstrated the occurrence of a single species, Cichla kelberi. A single haplotype was observed for the 16S and CR, while three were detected for COI, with a dominant haplotype present in 98.5% of the samples. The extreme low diversity of the transplanted C. kelberi evidenced a limited number of founding maternal lineages. The success of this colonization seems to rely mainly on abiotic factors, such as increased water transparency of lentic environments that favor visual predators that along with the absence of predators, have made C. kelberi a successful invader of these reservoirs.


Resumo Muitas espécies de Cichla colonizaram com sucesso lagos e reservatórios do Brasil desde os anos 1960, causando graves prejuízos à vida selvagem nesses locais. Neste estudo, 135 tucunarés foram coletados em um complexo de reservatórios a fim de identificar se representavam uma espécie dominante ou múltiplas espécies, uma vez que diversas espécies de Cichla foram registradas na bacia. Os espécimes foram identificados com base na coloração, dados morfométricos e merísticos, e por marcadores mitocondriais COI, 16S rDNA e Região Controle (RC). A sobreposição dos dados morfométricos e o padrão similar de coloração impediram a identificação utilizando as chaves de identificação disponíveis na literatura. Entretanto, as análises bayesiana e de máxima verossimilhança de dados moleculares demonstraram a ocorrência de uma única espécie, Cichla kelberi. Um único haplótipo foi observado para o 16S e RC, enquanto três foram detectados para o COI, com um haplótipo dominante presente em 98,5% das amostras. A baixa diversidade nos exemplares introduzidos de C. kelberi evidenciou um número limitado de linhagens maternas fundadoras. O sucesso da invasão parece depender de fatores abióticos, como a maior transparência da água de ambientes lênticos que favorece predadores visuais que, atrelado à ausência de predadores, fez do C. kelberi um invasor bem-sucedido nesses reservatórios.


Assuntos
Animais , Ciclídeos/genética , Filogenia , Variação Genética/genética , Haplótipos/genética , Lagos , Teorema de Bayes
2.
Braz. j. biol ; 84: e253852, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355905

RESUMO

Abstract The aim objective of this study was to determine the trophic ecology of juvenile and adult Acestrorhynchus falcirostris during the rising and flood (high-water) period in six island lakes adjacent to the Solimões River. As such, we investigated: i) the trophic position, through the fractional trophic niche; ii) the niche breadth; iii) niche overlap and iv) the food strategy of the species. The specimens were collected during the years 2014 to 2017, using gillnets with mesh sizes ranging from 30 to 120mm between opposite knots. Through the analysis of stomach contents, the preference in the consumption of items of animal origin was observed. Juveniles consumed insects in greater proportions (IAi% = 50%), while adults consumed fish (IAi%=99,98%). Despite the large supply of food items available in the high-water period, juveniles were the only ones to consume items of allochthonous origin, such as insects. Juveniles presented a different dietary strategy and dietary composition to adults. Juveniles were omnivores with a generalist strategy, while adults were piscivores with a specialist strategy. Thus, the food composition, niche breadth, trophic position and feeding strategy of Acestrorhynchus falcirostris change due to the stage of development.


Resumo O objetivo deste estudo foi determinar a ecologia trófica de juvenis e adultos de Acestrorhynchus falcirostris durante o período de enchente e cheia em seis lagos de ilha adjacentes ao rio Solimões. Assim, investigamos: i) a posição trófica, através do nicho trófico fracional; ii) a largura de nicho; iii) sobreposição de nicho; iv) a estratégia alimentar. Os espécimes foram coletados durante os anos de 2014 a 2017, utilizando redes de emalhar com malha variando de 30 a 120mm entre nós opostos. Por meio da análise do conteúdo estomacal, observamos a preferência no consumo de itens de origem animal. Os juvenis consumiram insetos em maiores proporções (IAi% = 50%), enquanto os adultos consumiram preferencialmente peixes (IAi% = 99,98%). Apesar da grande oferta de alimentos disponíveis no período da cheia, os juvenis eram os únicos a consumir itens de origem alóctone, como por exemplo, os insetos. Os juvenis apresentaram uma estratégia alimentar e composição alimentar diferente para os adultos. Os juvenis foram considerados onívoros com uma estratégia generalista, enquanto os adultos foram considerados piscívoros com uma estratégia alimentar mais especialista. Assim, a composição alimentar, amplitude do nicho, posição trófica e a estratégia alimentar de Acestrorhynchus falcirostris muda em função do estágio de desenvolvimento.


Assuntos
Animais , Rios , Caraciformes , Estações do Ano , Lagos , Ecossistema , Cadeia Alimentar , Peixes , Conteúdo Gastrointestinal
3.
Braz. j. biol ; 83: e244494, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285607

RESUMO

Abstract Since water is one of the essentials for life, the presence and quality of water in the habitat is extremely important. Therefore, water quality change and management of Lake Aygır was investigated in this study. For this, water samples collected from the lake and the irrigation pool between May 2015 and May 2016 were analyzed monthly. Spectrophotometric, titrimetric and microbiological methods were used to determine the water quality. According to some water quality regulations, HCO3, NH4, Cu, Mo, Br, fecal coliform and total suspended solid (TSS) values were found above the limit values. The other 29 parameters comply with Turkish national and international legislations. Lake Aygır was negatively affected by the surrounding settlements and agricultural activities. It is thought that the water resource should be monitored periodically and remedial studies should be done to prevent parameters exceeding the limits. However, Lake Aygır was generally suitable for drinking, use, fishing and irrigation.


Resumo Como a água é um dos elementos essenciais para a vida, a presença e a qualidade da água no habitat são extremamente importantes. Portanto, a mudança da qualidade da água e a gestão do lago Aygır foram investigadas neste estudo. Para isso, amostras de água coletadas no lago e na piscina de irrigação entre maio de 2015 e maio de 2016 foram analisadas mensalmente. Métodos espectrofotométricos, titulométricos e microbiológicos foram usados para determinar a qualidade da água. De acordo com alguns regulamentos de qualidade da água, os valores de HCO3, NH4, Cu, Mo, Br, coliformes fecais e total sólido suspenso (TSS) foram encontrados acima dos valores limite. Os outros 29 parâmetros estão em conformidade com as legislações nacionais e internacionais turcas. O lago Aygır foi afetado negativamente pelos assentamentos e atividades agrícolas ao redor. Pensa-se que o recurso hídrico deve ser monitorado periodicamente e estudos corretivos devem ser feitos para evitar que os parâmetros ultrapassem os limites. No entanto, o lago Aygır era geralmente adequado para beber, usar, pescar e irrigar.


Assuntos
Poluentes Químicos da Água/análise , Lagos , Turquia , Qualidade da Água , Monitoramento Ambiental , Pesqueiros
4.
Artigo em Inglês | MEDLINE | ID: mdl-36069784

RESUMO

We present two strains affiliated with the GKS98 cluster. This phylogenetically defined cluster is representing abundant, mainly uncultured freshwater bacteria, which were observed by many cultivation-independent studies on the diversity of bacteria in various freshwater lakes and streams. Bacteria affiliated with the GKS98 cluster were detected by cultivation-independent methods in freshwater systems located in Europe, Asia, Africa and the Americas. The two strains, LF4-65T (=CCUG 56422T=DSM 107630T) and MWH-P2sevCIIIbT (=CCUG 56420T=DSM 107629T), are aerobic chemoorganotrophs, both with genome sizes of 3.2 Mbp and G+C values of 52.4 and 51.0 mol%, respectively. Phylogenomic analyses based on concatenated amino acid sequences of 120 proteins suggest an affiliation of the two strains with the family Alcaligenaceae and revealed Orrella amnicola and Orrella marina (= Algicoccus marinus) as being the closest related, previously described species. However, the calculated phylogenomic trees clearly suggest that the current genus Orrella represents a polyphyletic taxon. Based on the branching order in the phylogenomic trees, as well as the revealed phylogenetic distances and chemotaxonomic traits, we propose to establish the new genus Zwartia gen. nov. and the new species Z. hollandica sp. nov. to harbour strain LF4-65T and the new genus Jezberella gen. nov. and the new species J. montanilacus sp. nov. to harbour strain MWH-P2sevCIIIbT. Furthermore, we propose the reclassification of the species Orrella amnicola in the new genus Sheuella gen. nov. The new genera Zwartia, Jezberella and Sheuella together represent taxonomically the GKS98 cluster.


Assuntos
Alcaligenaceae , Gastrópodes , Alcaligenaceae/genética , Animais , Bactérias/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Lagos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
5.
Environ Monit Assess ; 194(10): 749, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36070025

RESUMO

The study focuses on the comprehensive research of geochemical and environmental roles of humic acids isolated from sediments of the urbanized lakes of Kola Peninsula, the Arctic. The sediments were collected from 5 water bodies located in the different parts of Murmansk city. The elemental analysis (C, H, N, and O percentage) of the samples was conducted. The molecular structure of the acids was investigated using solid-state CP/MAS 13C-NMR and FTIR spectroscopy methods. The findings revealed the specific geochemical and environmental features of the sediment humic acids in the urbanized aquatic ecosystems of the Arctic region. The process of humification in the studied lakes is slowed down due to cold climatic conditions and the high level of the pollution of the water bodies. The molecules of the humic acids are immature and high-oxygen. Therefore, on the one hand, they can actively leach the toxic metals from the components of the sediments. On the other hand, despite the relatively low content of chelate-forming groups in the structure of the humic acids, the stable organometallic compounds form due to high percentage of dispersed organic matter in the sediments and structural flexibility of the molecules of the acids. Furthermore, the geochemical composition of the sediments and their enrichment by the trace elements and hydrocarbons significantly influence on the character of the interaction between metals and humic acids.


Assuntos
Substâncias Húmicas , Lagos , Ecossistema , Monitoramento Ambiental , Substâncias Húmicas/análise , Lagos/análise , Água/análise
6.
Arch Microbiol ; 204(10): 605, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36070100

RESUMO

A novel sulfur-oxidizing bacterium, strain Am19T, was isolated from sediment of a brackish lake. Strain Am19T grew chemolithoautotrophically on inorganic sulfur compounds, and heterotrophic growth was not observed. Cells were rod-shaped with length of 1.1-3.0 µm and diameter of 0.5-0.8 µm. Growth was observed at 5-37 °C with an optimum growth temperature of 30 °C. The pH range for growth was 5.6-8.5 with an optimum pH of 6.6-7.0. Major fatty acids were summed feature 3 (C16: 1ω7c and/or C16: 1ω6c), summed feature 8 (C18: 1ω7c and/or C18: 1ω6c) and C16: 0. The sole respiratory quinone was ubiquinone-8. The complete genome of strain Am19T is composed of a circular chromosome with length of 2.5 Mbp and G + C content of 42.7 mol%. Phylogenetic analysis based on genomic data indicated that strain Am19T belongs to the genus Thiomicrorhabdus but is distinct from any existing species. Analysis of the 16S rRNA gene supported creation of a new species to accommodate strain Am19T. On the basis of genomic and phenotypic characteristics, strain Am19T (= NBRC 114602 T = BCRC 81336 T) is proposed as the type strain of a new species, with name of Thiomicrorhabdus immobilis sp. nov.


Assuntos
Lagos , Piscirickettsiaceae , Bactérias/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Japão , Lagos/microbiologia , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Enxofre
7.
Nat Commun ; 13(1): 5156, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056046

RESUMO

How lake temperatures across large geographic regions are responding to widespread alterations in ice phenology (i.e., the timing of seasonal ice formation and loss) remains unclear. Here, we analyse satellite data and global-scale simulations to investigate the contribution of long-term variations in the seasonality of lake ice to surface water temperature trends across the Northern Hemisphere. Our analysis suggests a widespread excess lake surface warming during the months of ice-off which is, on average, 1.4 times that calculated during the open-water season. This excess warming is influenced predominantly by an 8-day advancement in the average timing of ice break-up from 1979 to 2020. Until the permanent loss of lake ice in the future, excess lake warming may be further amplified due to projected future alterations in lake ice phenology. Excess lake warming will likely alter within-lake physical and biogeochemical processes with numerous implications for lake ecosystems.


Assuntos
Gelo , Lagos , Ecossistema , Estações do Ano , Temperatura , Água
8.
Sci Rep ; 12(1): 15006, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056130

RESUMO

This paper presents the state and spatial distribution of surface sediment contamination of 77 lakes in Poland by Cr, Ni, Cd, Pb, Zn, and Cu. The analyzed lakes were located within a network of nature protection areas in the territory of the European Union (EU). Spatial distribution of the heavy metals (HMs), factors favoring the delivery/accumulation of HMs in surface sediments, and pollution sources were analyzed. The results indicate the contamination of lake sediments by HMs, but the potentially toxic effects of HMs are only found in single lakes. The spatial distribution of Cr indicates predominant impacts of point sources, while for Pb, Ni, and Zn, the impact of non-point sources. The analysis showed the presence of areas with very high values of particular HMs (hot spots) in the western part of Poland, while a group of 5 lakes with very low values of Ni, Pb, and Zn (cold spots) was identified in the central part of Poland. Principal component analysis showed that presence of wetlands is a factor limiting HMs inflow to lakes. Also, lower HMs concentrations were found in lake surface sediments located in catchments with a higher proportion of national parks and nature reserves. Higher HMs concentrations were found in lakes with a high proportion of Special Protection Areas designated under the EU Birds Directive. The positive matrix factorization analysis identified four sources of HMs. High values of HMs concentrations indicate their delivery from industrial, urbanized, and agricultural areas. However, these impacts overlap, which disturbs the characteristic quantitative profiles assigned to these pollution sources.


Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos/análise , Lagos , Chumbo/análise , Metais Pesados/análise , Polônia , Medição de Risco , Poluentes Químicos da Água/análise
9.
J Environ Manage ; 320: 115858, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056487

RESUMO

Intensifying human activity coupled with climate change increase the transport of excess riverine nitrogen (N) and phosphorus (P) loading from catchment to lake, leading to eutrophication and harmful algal blooms worldwide. To improve understanding of multi-temporal patterns of riverine N and P export and their hydro-biogeochemical controls over both episodic events and long-term trend, we analyzed and interpreted high-frequency data of total nitrogen (TN), ammonia-nitrogen (NH4-N), and total phosphorus (TP) provided by an automatic water quality monitoring station in a typical agricultural catchment draining to Lake Chaohu, China. Mann-Kendall test revealed a significant decreasing trend of riverine N and P concentration most of the time during 2018-2020. At the sub-daily scale, intraday TN concentrations varied by more than 1 mg/L in 31.8% of the period. Monthly TN and TP concentrations were particularly high in December 2019, indicating combined effect of hydrologic (long dry antecedent period and subsequent intensive rainfall events) and anthropogenic controls (fertilization and agricultural drainage). Significantly higher TN concentrations in winter and TP concentrations in summer reflected coupled dominances of precipitation and temperature on hydrologic and biogeochemical processes. Rainfall events with very heavy intensity drove disproportionate N and P loads (more than 20% of the total export) in only 3.2% of the period. Moderate and very heavy events registered the highest TN and TP concentrations, respectively. Our results highlighted the importance of automatic water quality monitoring station to reveal dynamics of riverine N and P export, which may imply future nutrient loading abatement plans for lake-connected catchment.


Assuntos
Fósforo , Poluentes Químicos da Água , China , Monitoramento Ambiental , Eutrofização , Proliferação Nociva de Algas , Humanos , Lagos , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise
10.
J Environ Manage ; 320: 115885, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056492

RESUMO

Lateral hydrological connectivity (LHC) is a key process in maintaining aquatic biodiversity in river floodplain ecosystems. However, the effects of LHC loss on aquatic biodiversity are rarely studied. Here, we evaluated, for the first time, the responses of multiple facets (i.e., taxonomic, functional and phylogenetic) of alpha and beta diversity of freshwater molluscs to the LHC loss in 23 floodplain lakes in the Yangtze River Basin in China. Our results showed that taxonomic and functional alpha diversities were all significantly higher in connected lakes (CLs) than in disconnected lakes (DLs), whereas phylogenetic alpha diversity (Δ+) was lower in CLs than in DLs. For beta diversity facets, taxonomic (Tßsor) and phylogenetic (Pßsor) dissimilarities were slightly more contributed by the turnover component or equally contributed by the turnover and nestedness-resultant components both in CLs and DLs. Instead, functional beta diversity (Fßsor), generally showing much lower values than Tßsor and Pßsor, was mainly contributed by the nestedness-resultant component (76.6-84.0%), especially in DLs. We found that only functional dissimilarities were significantly higher in DLs than CLs, indicating a high level of functional diversity loss without replacement of species possessing traits sensitive to hydrological disconnection (i.e., large body size, lamellibranch body form, filter feeding, ovoviviparity and burrowing habits). In general, lake area, hydrological connectivity, aquatic vegetation coverage and nutrient levels (TN and TP) played important roles in structuring variation in molluscan alpha and beta diversities, although the three diversity facets responded to different environmental factors. Our results suggest that loss of connectivity to the mainstem river has negative impacts on molluscan assemblages in floodplain lakes. More importantly, as taxonomic, functional and phylogenetic diversities responded somewhat differently to the loss of hydrological connectivity, all of these biodiversity facets should be better incorporated into aquatic biodiversity assessment and conservation programs in large river floodplains.


Assuntos
Biodiversidade , Ecossistema , Hidrologia , Lagos , Filogenia , Rios
11.
J Environ Manage ; 320: 115871, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056490

RESUMO

In this study, we i) assessed the occurrence of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in sediments, pore water, and bulk water from three different areas in Lake Neusiedl, Austria, and ii) investigated mechanisms regulating adsorption and remobilization of these substances under different conditions via multiple lab-scale experiments. The adsorption capacity was mainly influenced by sediments' organic matter content, oxide composition, and pre-loading. Results suggest that a further increase of PFAS-concentrations in the open lake can be partly buffered by sediment transport to the littoral zone and adsorption to sediments in the extended reed belt. But, under current conditions, the conducted experiments revealed a real risk for mobilization of PFOS and PFOA from reed belt sediments that may lead to their transport back into the lake. The amount of desorbed PFAS is primarily dependent on water/sediment- or pore water/water-ratios and the concentration gradient. In contrast, water matrix characteristics and oxygen levels played a minor role in partitioning. The highest risk for remobilizing PFOS and PFOA was observed in experiments with sediments taken near the only major tributary to the lake (river Wulka), which had the highest pre-loading. The following management advice for water transport between high and low polluted areas can be derived based on the results. First, to reduce emissions into Lake waters from polluted tributaries like the Wulka river, we recommend diffuse pathways through the reed belt in the lake's littoral to reduce pollutant transport into the Lake and avoid high local sediment loadings. Second, water exchange with dried-up areas with probable higher loadings should be carefully handled and monitored to avoid critical back transport in the open lake. And third, general work in the reed belt or generally in the reed should be accompanied by monitoring to prevent uncontrolled remobilization in the future.


Assuntos
Ácidos Alcanossulfônicos , Poluentes Ambientais , Fluorcarbonetos , Poluentes Químicos da Água , Adsorção , Caprilatos , Monitoramento Ambiental/métodos , Fluorcarbonetos/análise , Sedimentos Geológicos , Lagos , Água , Poluentes Químicos da Água/análise
12.
J Environ Manage ; 320: 115905, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056496

RESUMO

Vertical radiocesium concentration profiles and inventories in sediments were measured in Lake Kasumigaura following the 2011 Fukushima Dai-ichi Nuclear Power Plant accident. Further measurements of radiocesium concentrations in suspended solids (SS) have been conducted since September 2012 in the Koise and Sakura rivers inflowing into the lake. Cesium-137 (137Cs) accumulated intensively near the inflow outlets in the lake. At the lake center, the 137Cs inventory in sediments increased during 2011-2014; however, few changes were observed during 2014-2016. The 137Cs surface concentration and inventory decreased considerably in Tsuchiura-iri Bay until 3 years after the accident, indicating 137Cs migration. However, the rate of decrease subsequently slowed due to the 137Cs supply from the river. The 137Cs concentration in river SS declined during 2012-2015; however, it remained 1-2 orders of magnitude above its pre-accident level. The entrainment coefficient of particulate 137Cs in the inflows was initially higher in the Koise River but decreased exponentially more rapidly in the Koise River than in the Sakura River until 2015. Therefore, in the future, the difference in 137Cs concentrations will be smaller. The 137Cs concentration in the Koise River will continue to decrease; thus, the difference in the 137Cs inventory between the northern and southern parts of the lake will decrease. Total estimated amounts of 137Cs in the entire lake were 3.72 × 1012 Bq in December 2012 and 4.18 × 1012 Bq in August 2016. The accumulated amount of 137Cs in the entire lake based on sediment analysis was similar to the riverine input of particulate 137Cs based on riverine SS analysis from December 2012‒;August 2016, confirming the high trapping performance of the lake for particulate matter provided by the basin. Moreover, the amount of 137Cs accumulated in the lake in 2016 may have originated from comparable rates of atmospheric deposition and riverine input. These findings provide useful insights for future prediction and management of radiocesium contamination and the effects of riverine inputs in general shallow lakes.


Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Poluentes Radioativos da Água , Radioisótopos de Césio/análise , Japão , Lagos , Centrais Nucleares , Poluentes Radioativos da Água/análise
13.
J Environ Manage ; 320: 115906, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36056497

RESUMO

Phosphorus (P) cycling by microbial activity is highly relevant in the eutrophication of lakes. In this context, the contents of organic (Po) and inorganic (Pi) phosphorus, the activity of acid (ACP) and alkaline (ALP) phosphomonoesterase (Pase), and the abundances of bacterial Pase genes (phoD, phoC, and phoX) were studied in sediments from Budi Lake, a eutrophic coastal brackish water lake in Chile. Our results showed spatiotemporal variations in P fractions, Pase activities, and Pase gene abundances. In general, our results showed higher contents of Pi (110-144 mg kg-1), Po (512-576 mg kg-1), and total P (647-721 mg kg-1) in sediments from the more anthropogenized sampling sites in summer compared with those values of Pi (86-127 mg kg-1), Po (363-491 mg kg-1) and total P (449-618 mg kg-1) in less anthropogenized sampling sites in winter. In concordance, sediments showed higher Pase activities (µg nitrophenyl phosphate g-1 h-1) in sediments from the more anthropogenized sampling sites (9.7-22.7 for ACP and 5.9 to 9.6 for ALP) compared with those observed in less anthropogenized sampling sites in winter (4.2-12.9 for ACP and 0.3 to 6.7 for ALP). Higher abundances (gene copy g-1 sediment) of phoC (8.5-19 × 108), phoD (9.2-47 × 106), and phoX (8.5-26 × 106) genes were also found in sediments from the more anthropogenized sampling sites in summer compared with those values of phoC (0.1-1.1 × 108), phoD (1.4-2.4 × 106) and phoX (0.7-1.2 × 106) genes in the less anthropogenized sites in winter. Our results also showed a positive correlation between P contents, Pase activities, and abundances of bacterial Pase genes, independent of seasonality. The present study provided information on the microbial activity involved in P cycling in sediments of Budi Lake, which may be used in further research as indicators for the monitoring of eutrophication of lakes.


Assuntos
Lagos , Poluentes Químicos da Água , Chile , China , Monitoramento Ambiental/métodos , Eutrofização , Sedimentos Geológicos , Monoéster Fosfórico Hidrolases , Fósforo/análise , Águas Salinas , Poluentes Químicos da Água/análise
14.
Ecotoxicol Environ Saf ; 241: 113817, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36068746

RESUMO

In this study, the effects of traditional copper (CuSO4.5H2O) and novel copper algaecides (Captain XTR, SeClear and Lake Guard Blue) were tested on Daphnia magna under acute (48 h) and chronic (21 d) exposure scenarios. The EC50 values calculated in the acute tests were between 0.5 and 0.6 mg Cu L-1 for all four compounds. Lake Guard Blue and CuSO4.5 H2O were more toxic than SeClear and Captain XTR. During the chronic test, the effects of SeClear (EC50: 0.274 mg Cu L-1) on reproduction and body length were larger than the effects of the other three copper-based algaecides (EC50: 0.436 mg Cu L-1 for CuSO4.5 H2O, 0.498 mg Cu L-1 for Captain XTR, and 0.295 mg Cu L-1 for Lake Guard Blue). Captain XTR had the strongest negative effect on body weight, whereas body weight was affected the least by CuSO4.5 H2O. The four copper compounds affected the age at first brood significantly, which was delayed by 1.8, 2.0, 2.3 and 3.2 days for Captain XTR, CuSO4.5H2O, Lake Guard Blue and SeClear, respectively. Intrinsic rate of population increase was lowest (0.145 d-1) at the highest dosage in the SeClear treatments. Chemical equilibrium modelling revealed that most copper was chelated with EDTA present in the artificial medium used. These combined results indicate that the toxicity of the novel copper algaecide SeClear to D. magna is greater than that of traditional copper algaecide. Prior to each Cu application, tests on the effects of Cu compounds on the organisms being targeted should be done, taking into consideration the water chemistry.


Assuntos
Herbicidas , Poluentes Químicos da Água , Animais , Peso Corporal , Cobre/análise , Daphnia , Herbicidas/toxicidade , Lagos , Poluentes Químicos da Água/análise
15.
Ecotoxicol Environ Saf ; 241: 113832, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36068758

RESUMO

Rapid development of aquaculture industry and increasing demand of various inputs (especially antibiotics), are suspected to promote the occurrence and spread of ARGs in aquaculture related environments. However, the occurrences of ARGs under different freshwater aquaculture practices are rarely known. Here, we investigated the seasonal profiles of the main ARGs, intI1 and bacteria in waters from three kinds of predominant freshwater aquaculture practices around the Honghu Lake (China), as well as their co-occurrences and interrelationships with antibiotics, heavy metals and general water quality. The results indicate that quinolone resistance genes (qnrB), tetracycline resistance genes (tetB and tetX) and sulfonamide resistance genes (sul1 and sul2) were the top five predominant ARGs with seasonal variations of abundance. Fish ponds were of the highest absolute abundances of tested ARGs than the other two modes. Crayfish ponds and their adjacent ditches shared similar ARGs profile. Different subtypes of ARGs belonging to the same class of resistance were varied in abundances. Some bacteria were predicted to carry different ARGs, which indicating multi-antibiotic resistances. Moreover, the combined environmental factors (antibiotics, heavy metals and water quality) partially shaped the profiles of ARGs and bacteria composition. Overall, this study provides new comprehensive understanding on the characterization of ARGs contamination in different freshwater aquaculture practices from the perspectives of environmental chemistry, microbiology and ecology. The results would benefit the optimization of aquaculture practices toward environmental integrity and sustainability.


Assuntos
Antibacterianos , Metais Pesados , Animais , Antibacterianos/farmacologia , Aquicultura , Bactérias/genética , China , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Lagos
16.
Sensors (Basel) ; 22(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36080846

RESUMO

This work aimed to detect the vegetation coverage and evaluate the benefits of afforestation and ecological protection. Unmanned aerial vehicle (UAV) aerial survey was adopted to obtain the images of tailings area at Ma'anshan near the Dianchi Lake estuary, so as to construct a high-resolution Digital Orthophoto Map (DOM) and high-density Dense Image Matching (DIM) point cloud. Firstly, the optimal scale was selected for segmentation by considering the terrain. Secondly, the visible-band difference vegetation index (VDVI) of the classified vegetation information of the tail mining area was determined from the index gray histogram, ground class error analysis, and the qualitative and quantitative analysis of the bimodal index. Then, the vegetation information was extracted by combining the random forest (RF) classification algorithm. Finally, the extracted two-dimensional (2D) vegetation information was mapped to the three-dimensional (3D) point cloud, and the redundant data was eliminated. Fractional vegetation cover (FVC) was counted in the way of surface to point and human-machine combination. The experimental results showed that the vegetation information extracted from the 2D image was mapped to the 3D point cloud in the form of surface to point, and the redundant bare ground information was eliminated. The statistical FVC was 36.06%. The field survey suggested that the vegetation information in the turf dam area adjacent to the open phosphate deposit accumulation area research area was sparse. Relevant measures should be taken in the subsequent mining to avoid ecological damage caused by expanded phosphate mining. In general, applying UAV measurement technology and related 2D and 3D products to detect the vegetation coverage in an open phosphate mine area was of practical significance and unique technical advantages.


Assuntos
Lagos , Tecnologia de Sensoriamento Remoto , Humanos , Mineração , Fosfatos
17.
Sensors (Basel) ; 22(17)2022 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-36081143

RESUMO

In some sectors of the water resources management, the digital revolution process is slowed by some blocking factors such as costs, lack of digital expertise, resistance to change, etc. In addition, in the era of Big Data, many are the sources of information available in this field, but they are often not fully integrated. The adoption of different proprietary solutions to sense, collect and manage data is one of the main problems that hampers the availability of a fully integrated system. In this context, the aim of the project is to verify if a fully open, cost-effective and replicable digital ecosystem for lake monitoring can fill this gap and help the digitalization process using cloud based technology and an Automatic High-Frequency Monitoring System (AHFM) built using open hardware and software components. Once developed, the system is tested and validated in a real case scenario by integrating the historical databases and by checking the performance of the AHFM system. The solution applied the edge computing paradigm in order to move some computational work from server to the edge and fully exploiting the potential offered by low power consuming devices.


Assuntos
Ecossistema , Lagos , Análise Custo-Benefício , Software , Qualidade da Água
18.
Zootaxa ; 5133(4): 451-485, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-36101088

RESUMO

The Oxynoemacheilus angorae species group is revised and 10 species are recognised, two of which are described herein as new. Oxynoemacheilus anatolicus, O. angorae, O. eregliensis, O. germencicus, O. isauricus, O. nasreddini, O. mediterraneus, and O. theophilii are endemic to west and Central Anatolia. Oxynoemacheilus cinicus and O. mesudae, both from Byk Menderes River drainage, are synonyms of O. germencicus. As First Revisers, we give priority to Oxynoemacheilus germencicus over O. cinicus. Oxynoemacheilus atili described from Lake Beyehir basin is a synonym of O. eregliensis. Oxynoemacheilus axylos, new species, from endorheic Lake Tuz basin (Cihanbeyli, Glyaz, Melendiz, and Samsam) is distinguished by possessing an almost truncate caudal-fin, a stout caudal peduncle, and elevated dorsal and ventral adipose crests. The new species is also distinguished by a minimum K2P sequence divergence of 1.6% in the mtDNA-COI barcode region from O. eregliensis, its closest relative. Oxynoemacheilus eliasi, new species, from the Kk Menderes and Gediz River drainages, is distinguished by having small, embedded scales on the belly, a narrow suborbital groove in male, an emarginate caudal fin, the caudal peduncle depth 1.31.5 times in its length, and the body depth decreasing between the dorsal and caudal-fin bases. The new species is also distinguished by a minimum K2P sequence divergence of 2.7% in the mtDNA-COI barcode region from O. theophilii, its closest relative.


Assuntos
Cipriniformes , Animais , Cipriniformes/genética , DNA Mitocondrial , Lagos , Masculino , Rios
19.
Zootaxa ; 5128(1): 44-60, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-36101187

RESUMO

Lacustricola margaritatus, a new species inhabiting small streams and swamps in the Lake Victoria basin in north-western Tanzania and southern Uganda, and the Lake Kyoga basin in central Uganda, is described. Lacustricola margaritatus is a small species with a moderately deep body, moderate dimorphism and pronounced dichromatism. It is distinguished from all other Procatopodidae by the following unique combination of characters: live male body colour pattern with vertically-elongated iridescent light blue patches at scale centres, forming a striped appearance of dotted longitudinal lines on the flanks, particularly evident in the two or three series below the mid-longitudinal line; male having deeply coloured unpaired fins with orange-brown in the proximal and median parts and a narrow black distal band; male with a yellow base along the pectoral fin; female with dark grey scale margins and dark grey patches on scales along mid-longitudinal series creating a narrow dark grey stripe; both sexes showing inconspicuous postopercular blotch; and in both sexes, the cephalic sensory system is entirely situated in open grooves at all levels. The new species has previously often been misidentified as L. pumilus, originally described as inhabiting the Lake Tanganyika basin in north-eastern Zambia, or 'L.' centralis, from the Lake Rukwa basin in south-western Tanzania. Lacustricola margaritatus differs from the above two species by morphometric and meristic characters, body and fin colouration, and in arrangement of the cephalic sensory system.


Assuntos
Ciprinodontiformes , Lagos , Nadadeiras de Animais , Animais , Feminino , Masculino , Rios
20.
Zootaxa ; 5168(2): 222-236, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-36101288

RESUMO

This study seeks to clarify the taxonomic identity of three adult frogs and two tadpoles from Rara Lake situated in Rara National Park, Mugu district, Western Nepal, using both phenotypic and mitochondrial sequence data (16S rRNA gene). Based on the molecular data, we determined our specimens belonged to two species; Paa cf. ercepeae (Dubois, 1974) and Paa rarica (Dubois, Matsui, and Ohler, 2001), and this assignment is also supported by morphology. Principal component analysis of phenotypic data clustered species into large-bodied (SVL > 55 mm) and small-bodied (SVL < 55 mm) groups. The molecular data suggest that Paa rarica belonged to a group that contains several undescribed lineages and that Paa liebigii (Gnther, 1860) hosts extensive cryptic diversity. Our study also documents that Paa species in the Himalayan region are more widely distributed than previously believed.


Assuntos
Lagos , Parques Recreativos , Animais , Anuros , Nepal , Filogenia , RNA Ribossômico 16S/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...