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1.
Artigo em Inglês | MEDLINE | ID: mdl-36078537

RESUMO

Aljustrel, Lousal and S. Domingos mines are located in the Iberian Pyrite Belt (IPB), one of the greatest massive sulfide ore deposits worldwide. These mines' surrounding streams are affected by Acid Mine Drainage (AMD). The main purpose of this study was to understand AMD influence in the water quality and diatom behavior. Thus, waters and diatoms were sampled in 6 sites from the 3 selected mines on winter and summer of 2016. The highest concentrations were found in acidic sites: A3 (Aljustrel-Al, Cd, Cu, Fe and Zn (and lowest pH)) and L1 (Lousal-As, Mn, Ca, Mg, SO42- and conductivity). The most abundant diatom species was Pinnularia aljustrelica with 100% of dominance in A3 and S1 acidic sites, which puts in evidence this species adaptation to AMD harsh conditions. Multivariate cluster analysis allowed us to reinforce results from previous studies, where spatial differences were more relevant than seasonal ones. In 12 years (2004-2016), and with many transformations undertaken (re-opening and rehabilitation), there is a conservative behavior in the biological species (diatoms) and physicochemical concentrations (metals, pH and sulfates) from these three mining sites. This type of biogeochemical diagnosis is necessary for the sustainable use of these waters and the prevention of the polluting process, aimed to protect the water ecosystem and its biodiversity.


Assuntos
Diatomáceas , Poluentes Químicos da Água , Ácidos/análise , Ecossistema , Monitoramento Ambiental/métodos , Água Doce , Hidrobiologia , Portugal , Rios , Poluentes Químicos da Água/análise
2.
Artigo em Inglês | MEDLINE | ID: mdl-35805409

RESUMO

Studying the spatial management scope of the river ecological corridor is a crucial step in effectively managing river health problems. For various purposes and needs, human beings intervene excessively in the river, resulting in the problems of unclear spatial scope, unclear ownership, and unreasonable functional utilization of the river ecological corridor. However, there is scarce research on the management scope of the river ecological corridor at present, and on the coordination relationship with territorial spatial protection planning. Therefore, in order to solve this key problem, this paper reviews and summarizes the current research status and development trends in terms of the concept, components, and other basic theories of the river ecological corridor, as well as relevant policy regulations. The relationship between the spatial scope of the river ecological corridor and the territorial spatial control line is analyzed, including the relationship with the river shoreline, aquatic ecological redline, "three control lines" and other control lines. Accordingly, this study reviewed the spatial management and control scope of the river ecological corridor. It also determined that the boundary line of the river shoreline management is the minimum line, the aquatic ecological redline, and the "three control lines" are the outermost boundary lines, in which the aquatic ecological redline has priority over other control lines. It also points out the thinking of determining the management scope in the protection and restoration of the river ecological corridor in the future. Our findings can provide a decision-making basis for the management of river ecological space.


Assuntos
Hidrobiologia , Rios , China , Conservação dos Recursos Naturais , Ecossistema , Humanos
3.
Environ Sci Pollut Res Int ; 29(43): 65128-65143, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35482240

RESUMO

The aquatic ecological health status was focused on the Huai River Basin (HRB) from the aspects of water quantity, water quality, water ecology, river connectivity, and riparian habitat environment. Ten monitoring sections were set up in the middle and upper reaches of HRB, and 5 experiments of each section were conducted in July and December from 2012 to 2014. Thus, relevant data on the species, the density of phytoplankton, zooplankton and benthic animals, the concentration of water physicochemical variables, and riparian habitat quality were obtained. Eleven key impact factors were chosen using frequency statistics, theoretical analysis, and correlation analysis methods, forming the evaluation index system of aquatic ecological health. Then, the indicator weight value was determined by the combined weight method, and the health degree was evaluated by the comprehensive index method. On the whole, the aquatic ecological health degree of the upper sections (D1 ~ D3) of the Shaying River ranges from 0.334 to 0.927, which is generally in a "sub-healthy" state. The aquatic ecological health degree of the main section of the Huai River (D8 ~ D10) ranges from 0.362 to 0.777, which is in the "critical" or "sub-healthy" state. The Huaidian Sluice (D5) and Fuyang Sluice (D6) in the middle and lower reaches of the Shaying River had the worst aquatic ecological health. Its water ecological health range is 0.283-0.523, and most of them are under "sub-pathologic." The research results have important theoretical and practical significance. They can enrich the evaluation theories and methods of river aquatic ecological health, help to grasp the aquatic ecological health status in HRB, and provide basic support for aquatic ecological protection and water pollution control in sluice-controlled rivers.


Assuntos
Monitoramento Ambiental , Rios , Animais , China , Monitoramento Ambiental/métodos , Hidrobiologia , Qualidade da Água
4.
Yakugaku Zasshi ; 142(1): 39-64, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-34980750

RESUMO

Lakes Sagami and Tsukui are reservoirs constructed by connecting to the Sagami River. Because of eutrophication of the lakes, cyanobacteria have appeared every year. This review deals with phenomena related to occurrence of cyanobacteria that have been observed for 40 years since 1974 at the lakes. These 40 years of observations raised three interesting issues including the retention of cyanobacteria on their surfaces. These phenomena have been attributed to the usual factors, such as illuminance, nutrition and water temperature, but our research results suggested that they cannot be resolved without the introduction of another factor. We have attempted to elucidate various phenomena involving cyanobacteria in lake ecosystems by chemical ecological methods using volatile organic compounds (VOCs) produced by the cyanobacteria as indicators. One of the VOCs, ß-cyclocitral, was significantly involved in the above phenomena, which was considered to be produced by the carotenoid cleavage dioxygenase (CCD) of the cyanobacteria. ß-Cyclocitral was not produced in the two known CCDs, but two additional CCDs to Microcystis aeruginosa participated to produce the ß-cyclocitral. These CCDs did not directly produce ß-cyclocitral, but it was accumulated in cells as their precursors. The released ß-cyclocitral underwent a Baeyer-Villiger-like oxidation. It was speculated that Microcystis activated the CCD genes through density stress and produced ß-cyclocitral, which acted as an allelopathic substance. As a result, the number of cells of cyanobacteria decreased, and the resulting nitrogen and phosphorus were fed to the living cyanobacteria. It is postulated that this "quorum sensing" was functioning in the above-mentioned issues.


Assuntos
Cianobactérias/fisiologia , Ecossistema , Água Doce/microbiologia , Hidrobiologia/métodos , Percepção de Quorum , Aldeídos/metabolismo , Cianobactérias/enzimologia , Cianobactérias/metabolismo , Dioxigenases/metabolismo , Diterpenos/metabolismo , Microcystis/metabolismo , Nitrogênio/metabolismo , Oxirredução , Fósforo/metabolismo , Compostos Orgânicos Voláteis/metabolismo
5.
Conserv Biol ; 36(1): e13762, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34057237

RESUMO

In some cases, wildlife management objectives directed at multiple species can conflict with one another, creating species trade-offs. For managers to effectively identify trade-offs and avoid their undesirable outcomes, they must understand the agents involved and their corresponding interactions. A literature review of interspecific trade-offs within freshwater and marine ecosystems was conducted to illustrate the scope of potential interspecific trade-offs that may occur. We identified common pitfalls that lead to failed recognition of interspecific trade-offs, including, single-species management and limited consideration of the spatial and temporal scale of ecosystems and their management regimes. We devised a classification framework of common interspecific trade-offs within aquatic systems. The classification can help managers determine whether the conflict is species based through direct relationships (i.e., predator-prey, competition, other antagonistic relationships) or indirect relationships involving intermediate species (i.e., conflict-generating species) or whether the conflict is driven by opposing management objectives for species that would otherwise not interact (i.e., nontarget management effects). Once the nature and scope of trade-offs are understood, existing decision-making tools, such as structured decision-making and real-options analysis, can be incorporated to improve the management of aquatic ecosystems. Article Impact Statement: A synthesis of interspecific trade-offs in aquatic ecosystems supports their identification and resolution.


Un Marco de Clasificación para Compensaciones Interespecíficas en Ecología Acuática Resumen En algunos casos, los objetivos del manejo de fauna dirigidos a muchas especies pueden entrar en conflicto entre sí creando compensaciones entre las especies. Para que los manejadores identifiquen efectivamente estas compensaciones y eviten sus resultados no deseados, deben entender a los agentes involucrados y sus interacciones correspondientes. Se realizó una revisión literaria de las compensaciones interespecíficas dentro de los ecosistemas marinos y de agua dulce para ilustrar el alcance de las compensaciones interespecíficas que pueden ocurrir. Identificamos dificultades comunes que llevan al reconocimiento fallido de las compensaciones interespecíficas, incluyendo el manejo de una sola especie y sus regímenes de manejo. Diseñamos un marco de clasificación de compensaciones interespecíficas comunes dentro de los ecosistemas acuáticos. La clasificación puede ayudar a los manejadores a determinar si el conflicto está basado en las especies por sus relaciones directas (es decir, depredador-presa, competencia, otras relaciones antagonistas) o por relaciones indirectas que involucran a otras especies (es decir, efectos del manejo de especies que no son el objetivo). Una vez que se entiende la naturaleza y el alcance de las compensaciones, las herramientas de toma de decisión existentes, como la toma estructurada de decisiones y el análisis de opciones reales, pueden incorporarse para mejorar el manejo de los ecosistemas acuáticos.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Hidrobiologia
6.
Sci Total Environ ; 815: 152365, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34963591

RESUMO

The analysis of community structure in studies of freshwater ecology often requires the application of dimensionality reduction to process multivariate data. A high number of dimensions (number of taxa/environmental parameters × number of samples), nonlinear relationships, outliers, and high variability usually hinder the visualization and interpretation of multivariate datasets. Here, we proposed a new statistical design using Uniform Manifold Approximation and Projection (UMAP), and community partitioning using Louvain algorithms, to ordinate and classify the structure of aquatic biota in two-dimensional space. We present this approach with a demonstration of five previously published datasets for diatoms, macrophytes, chironomids (larval and subfossil), and fish. Principal Component Analysis (PCA) and Ward's clustering were also used to assess the comparability of the UMAP approach compared to traditional approaches for ordination and classification. The ordination of sampling sites in 2-dimensional space showed a much denser, and easier to interpret, grouping using the UMAP approach in comparison to PCA. The classification of community structure using the Louvain algorithm in UMAP ordinal space showed a high classification strength for data with a high number of dimensions than the cluster patterns obtained with the use of a Ward's algorithm in PCA. Environmental gradients, presented via heat maps, were overlayed with the ordination patterns of aquatic communities, confirming that the ordinations obtained by UMAP were ecologically meaningful. This is the first study that has applied a UMAP approach with classification using Louvain algorithms on ecological datasets. We show that the performance of local and global structures, as well as the number of clusters determined by the algorithm, make this approach more powerful than traditional approaches.


Assuntos
Algoritmos , Biomarcadores Ambientais , Animais , Análise por Conglomerados , Hidrobiologia , Análise de Componente Principal
7.
Sci Rep ; 11(1): 19201, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34725464

RESUMO

A variety of mammals suppress reproduction when they experience poor physical condition or environmental harshness. In many marine mammal species, reproductive impairment has been correlated to polychlorinated biphenyls (PCBs), the most frequently measured chemical pollutants, while the relative importance of other factors remains understudied. We investigate whether reproductively active females abandon investment in their foetus when conditions are poor, exemplified using an extensively studied cetacean species; the harbour porpoise (Phocoena phocoena). Data on disease, fat and muscle mass and diet obtained from necropsies in The Netherlands were used as proxies of health and nutritional status and related to pregnancy and foetal growth. This was combined with published life history parameters for 16 other areas to correlate to parameters reflecting environmental condition: mean energy density of prey constituting diets (MEDD), cumulative human impact and PCB contamination. Maternal nutritional status had significant effects on foetal size and females in poor health had lower probabilities of being pregnant and generally did not sustain pregnancy throughout gestation. Pregnancy rates across the Northern Hemisphere were best explained by MEDD. We demonstrate the importance of having undisturbed access to prey with high energy densities in determining reproductive success and ultimately population size for small cetaceans.


Assuntos
Estado Nutricional/fisiologia , Phocoena/metabolismo , Reprodução/fisiologia , Animais , Cetáceos/metabolismo , Conservação dos Recursos Naturais/métodos , Metabolismo Energético/fisiologia , Feminino , Hidrobiologia/métodos , Países Baixos , Bifenilos Policlorados/efeitos adversos , Bifenilos Policlorados/análise , Gravidez , Reprodução/efeitos dos fármacos , Comportamento Sexual Animal/efeitos dos fármacos , Poluentes Químicos da Água/efeitos adversos , Poluentes Químicos da Água/análise
8.
J Gen Virol ; 102(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34356002

RESUMO

The family Marnaviridae comprises small non-enveloped viruses with positive-sense RNA genomes of 8.6-9.6 kb. Isolates infect marine single-celled eukaryotes (protists) that come from diverse lineages. Some members are known from metagenomic studies of ocean virioplankton, with additional unclassified viruses described from metagenomic datasets derived from marine and freshwater environments. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Marnaviridae, which is available at ictv.global/report/marnaviridae.


Assuntos
Genoma Viral , Filogenia , Vírus de RNA/classificação , Vírus de RNA/genética , Animais , Proteínas do Capsídeo , Eucariotos , Especificidade de Hospedeiro , Hidrobiologia , Metagenômica , Infecções por Vírus de RNA/virologia , Vírus de RNA/ultraestrutura , RNA Viral , Vírion/classificação , Vírion/genética , Vírion/ultraestrutura , Replicação Viral
9.
Am J Trop Med Hyg ; 104(4): 1394-1403, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432900

RESUMO

Onchocerciasis, caused by infection with Onchocerca volvulus, has been targeted for elimination by 2030. Currently, onchocerciasis elimination programs rely primarily on mass distribution of ivermectin. However, ivermectin alone may not be sufficient to achieve elimination in some circumstances, and additional tools may be needed. Vector control has been used as a tool to control onchocerciasis, but vector control using insecticides is expensive and ecologically detrimental. Community-directed removal of the trailing vegetation black fly larval attachment sites (slash and clear) has been shown to dramatically reduce vector biting densities. Here, we report studies to optimize the slash and clear process. Conducting slash and clear interventions at Simulium damnosum sensu stricto breeding sites located within 2 km of afflicted communities resulted in a 95% reduction in vector biting. Extending slash and clear further than 2 km resulted in no further decrease. A single intervention conducted at the first half of the rainy season resulted in a 97% reduction in biting rate, whereas an intervention conducted at the end of the rainy season resulted in a 94% reduction. Vector numbers in any of the intervention villages did not fully recover by the start of the following rainy season. These results suggest that slash and clear may offer an inexpensive and effective way to augment ivermectin distribution in the effort to eliminate onchocerciasis in Africa.


Assuntos
Participação da Comunidade/métodos , Controle de Insetos/métodos , Insetos Vetores/parasitologia , Onchocerca volvulus/patogenicidade , Oncocercose/prevenção & controle , Oncocercose/transmissão , Simuliidae/parasitologia , Animais , Humanos , Hidrobiologia/métodos , Mordeduras e Picadas de Insetos/prevenção & controle , Oncocercose/epidemiologia , Plantas , Chuva , Estações do Ano , Simuliidae/fisiologia , Uganda
10.
IEEE Trans Cybern ; 51(8): 4286-4297, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31449042

RESUMO

Lots of evidence has indicated that many kinds of animals can achieve goal-oriented navigation by spatial cognition and dead reckoning. The geomagnetic field (GF) is a ubiquitous cue for navigation by these animals. Inspired by the goal-oriented navigation of animals, a novel long-distance underwater geomagnetic navigation (LDUGN) method is presented in this article, which only utilizes the declination component ( D ) and inclination component ( I ) of GF for underwater navigation without any prior knowledge of the geographical location or geomagnetic map. The D and I measured by high-precision geomagnetic sensors are compared periodically with that of the destination to determine the velocity and direction in the next step. A model predictive control (MPC) algorithm with control and state constraints is proposed to achieve the control and optimization of navigation trajectory. Because the optimal control is recalculated at each sampling instant, the MPC algorithm can overcome interferences of geomagnetic daily fluctuation, geomagnetic storms, ocean current, and geomagnetic local anomaly. The simulation results validate the feasibility and accuracy of the proposed algorithm.


Assuntos
Algoritmos , Hidrobiologia , Modelos Biológicos , Navegação Espacial/fisiologia , Animais , Organismos Aquáticos/fisiologia , Simulação por Computador , Magnetismo , Movimentos da Água
11.
Rapid Commun Mass Spectrom ; 35(2): e8992, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33125783

RESUMO

RATIONALE: Dried blood spots (DBSs) are gaining popularity for biomarker analyses in ecological research due to their advantages for use in field-based research and in remote settings; however, many DBS biomarkers remain unvalidated. We validated the application of compound-specific stable nitrogen isotope analyses of amino acids (CSIA-AAs) to field-prepared DBSs for determining trophic positions of wild-caught Arctic char (Salvelinus alpinus). METHODS: Whole blood and muscle from Arctic char were collected, and DBSs were created in the field. We measured the stable nitrogen isotope ratios (expressed as δ15 N values) of the amino acids glutamic acid (Glu) and phenylalanine (Phe) isolated from Arctic char samples using CSIA-AAs. We then compared amino acid δ15 N values from DBSs and the other sample types (whole blood and muscle) from the same specimens. We calculated and compared trophic position estimates generated from whole blood, DBSs, and muscle. RESULTS: The δ15 N values of Glu and Phe, as well as trophic position estimates from DBSs, were highly correlated with δ15 N values and estimates from both whole blood and muscle. The DBS amino acid δ15 N values and trophic position estimates agreed well with those from whole blood. Although mean differences between amino acid δ15 N values from DBSs and muscle were noted, the offsets were small and resulted in a 0.2 mean difference between trophic position estimates for DBSs and muscle. CONCLUSIONS: We demonstrate that the application of CSIA-AAs to field-prepared DBSs of Arctic char generates similar trophic position estimates to those from whole blood and muscle. We suggest that DBSs could be developed as a minimally invasive sampling technique to study feeding ecology of wild fish and perhaps other organisms of interest.


Assuntos
Aminoácidos , Teste em Amostras de Sangue Seco/métodos , Teste em Amostras de Sangue Seco/normas , Isótopos de Nitrogênio/sangue , Truta/sangue , Aminoácidos/sangue , Aminoácidos/química , Animais , Cromatografia Gasosa-Espectrometria de Massas , Hidrobiologia
12.
Int J Mol Sci ; 22(17)2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34502500

RESUMO

In this paper, we review the effects of large-scale neonicotinoid contaminations in the aquatic environment on non-target aquatic invertebrate and vertebrate species. These aquatic species are the fauna widely exposed to environmental changes and chemical accumulation in bodies of water. Neonicotinoids are insecticides that target the nicotinic type acetylcholine receptors (nAChRs) in the central nervous systems (CNS) and are considered selective neurotoxins for insects. However, studies on their physiologic impacts and interactions with non-target species are limited. In researches dedicated to exploring physiologic and toxic outcomes of neonicotinoids, studies relating to the effects on vertebrate species represent a minority case compared to invertebrate species. For aquatic species, the known effects of neonicotinoids are described in the level of organismal, behavioral, genetic and physiologic toxicities. Toxicological studies were reported based on the environment of bodies of water, temperature, salinity and several other factors. There exists a knowledge gap on the relationship between toxicity outcomes to regulatory risk valuation. It has been a general observation among studies that neonicotinoid insecticides demonstrate significant toxicity to an extensive variety of invertebrates. Comprehensive analysis of data points to a generalization that field-realistic and laboratory exposures could result in different or non-comparable results in some cases. Aquatic invertebrates perform important roles in balancing a healthy ecosystem, thus rapid screening strategies are necessary to verify physiologic and toxicological impacts. So far, much of the studies describing field tests on non-target species are inadequate and in many cases, obsolete. Considering the current literature, this review addresses important information gaps relating to the impacts of neonicotinoids on the environment and spring forward policies, avoiding adverse biological and ecological effects on a range of non-target aquatic species which might further impair the whole of the aquatic ecological web.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Inseticidas/efeitos adversos , Neonicotinoides/efeitos adversos , Animais , Ecossistema , Hidrobiologia , Inseticidas/farmacologia , Invertebrados/efeitos dos fármacos , Neonicotinoides/farmacologia , Neurotoxinas/farmacologia , Receptores Nicotínicos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade
13.
Sci Rep ; 10(1): 21531, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33298993

RESUMO

Environmental DNA (eDNA) is increasingly popular as a useful non-invasive method to monitor and study biodiversity and community structure in freshwater and marine environments. To effectively extract eDNA from the filter surface is a fundamental factor determining the representativeness of the samples. We improved the eDNA extraction efficiency of an established Sterivex method by 12- to 16-fold using a larger volume of lysis buffer mix coupled with backflushing the cartridges. The DNeasy extraction column could be overloaded when the environmental sample input is high, possibly due to a higher nonspecific binding present in environmental samples, thus resulting in a relatively lower quantity measured. Therefore, we included an internal control DNA in the extraction to monitor the extraction and purification efficiencies in field samples, which is crucial for quantification of original eDNA concentration. The use of Takara Probe qPCR Mix supplemented with protein-based additives improved the robustness of the real time PCR assay on inhibitor-rich environmental samples, but prior purification by Qiagen PowerClean Pro Cleanup kit could be essential for inhibitor-rich water samples, even though the recovery rate was unexpectedly low (average 33.0%). The improved extraction and quantification complement the qualitative analyses including metabarcoding and metagenomics in field application.


Assuntos
DNA Ambiental/isolamento & purificação , DNA/isolamento & purificação , Hidrobiologia/métodos , Animais , Biodiversidade , DNA/genética , DNA Ambiental/genética , Ecossistema , Monitoramento Ambiental/métodos , Filtração/métodos , Metagenômica/métodos , Água/análise
14.
Sci Rep ; 10(1): 22348, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339890

RESUMO

Many environmental flow (e-flow) studies and applications have predominantly used state-(i.e., at a single time point) and rate-(i.e., temporal change) based demographic characteristics of species representing lower trophic levels (e.g., fish communities) to build flow-ecology relationships, rather than using a process that incorporates population dynamics. Recent studies have revealed the importance of incorporating data on species traits when building flow-ecology relationships. The effects of flow on keystone megafauna species (i.e., body mass ≥ 30 kg) reverberate through entire food webs; however, the relationships between flow and these species are not well understood, limiting the scope of the relationships used in flow management. Here, we fill this gap by incorporating the habitat selection traits at different flows of a freshwater apex predator, Ganges River dolphin (GRD, Platanista gangetica gangetica), which plays a significant role in maintaining the structure, functions and integrity of the aquatic ecosystem. Using temporally and spatially measured GRD habitat selection traits, we quantified flow-ecology responses in the Karnali River of Nepal during the low-flow season when habitat was heavily reduced and water demand was highest. We define ecological responses as suitable habitat templates with enough usable surface area to support GRD fitness by improving reproduction and survival. We measured the available and occupied habitats to develop flow-ecology responses. Variation in flow resulted in substantial differences in the ecological response across time and space, suggesting that aquatic species adjusted in a variety of habitats to support their life histories and maintain viable populations. The limited availability of suitable habitats combined with uninformed water regulations by humans likely places GRDs under severe physiological stress during low-water seasons (i.e., January-April), suggesting that  reduced flows contribute to the process of endangering and extirpating highly sensitive endemic aquatic biodiversity. Our study reveals that ad hoc or experience-based flow management is no longer tenable to maintain the integrity and functionality of aquatic ecosystems. We stress that quantifying the flow-ecology relationships of foundational species, particularly megafauna, in response to flow variation is crucial for monitoring the effects of water alterations and determining the minimum flows needed for maintaining healthy and functional freshwater ecosystems in the Anthropocene.


Assuntos
Conservação dos Recursos Naturais , Golfinhos/fisiologia , Ecossistema , Hidrobiologia , Animais , Peixes , Cadeia Alimentar , Água Doce , Humanos , Nepal , Dinâmica Populacional , Rios , Estações do Ano
15.
Sci Rep ; 10(1): 18798, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33139770

RESUMO

Here we quantify the effects of artisanal fisheries on the ecology of a small cetacean, the Ganges River dolphin (Platanista gangetica gangetica, GRD), in a large river system of Nepal. We examine the size-classes of fisheries' catches, behavioural changes in GRD in response to fishing activities, and diel overlap between GRD and fishing activity. We observed high human exploitation rates (> 60% of the total catch per effort) of GRD-preferred prey sizes, indicating risks of high resource competition and dietary overlap, especially during the low water season when resource availability is reduced. Competitive interactions in the feeding niches during the low water season, plus temporal overlap between the peak exploitation and critical life-history events (e.g., reproduction), likely have ecological consequences. Furthermore, we detected 48% (95% CI 43-52%) increase in the chance of behavioural changes among dolphins exposed to anthropopressure (fishing activity), risking social behaviour impairment in exposed dolphins. The higher diel overlap and increased diel coefficient as the surveys progressed towards the monsoon season suggest temporal shifts in GRD socio-behavioural states and seasonal effects on resource partitioning, respectively. This work identifies drivers of small cetaceans-fisheries interactions and their consequences, and can be used to help reduce biologically significant fishing impacts on small cetaceans. Mitigation strategies, together with river sanctuary and distanced-based approaches, should be urgently included in a framework of ecosystem-based management.


Assuntos
Comportamento Animal/fisiologia , Conservação dos Recursos Naturais , Golfinhos/fisiologia , Golfinhos/psicologia , Comportamento Alimentar/fisiologia , Pesqueiros , Hidrobiologia , Rios , Estações do Ano , Animais , Humanos , Nepal , Reprodução , Comportamento Social
16.
Plant J ; 104(6): 1504-1519, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33037691

RESUMO

Eutrophication leads to epiphyte blooms on seagrass leaves that strongly affect plant health, yet the actual mechanisms of such epiphyte-induced plant stress remain poorly understood. We used magnetic optical sensor nanoparticles in combination with luminescence lifetime imaging to map the O2 concentration and dynamics in the heterogeneous seagrass phyllosphere under changing light conditions. By incorporating magnetite into the sensor nanoparticles, it was possible to image the spatial O2 distribution under flow over seagrass leaf segments in the presence of a strong magnetic field. Local microniches with low leaf surface O2 concentrations were found under thick epiphytic biofilms, often leading to anoxic microhabitats in darkness. High irradiance led to O2 supersaturation across most of the seagrass phyllosphere, whereas leaf microenvironments with reduced O2 conditions were found under epiphytic biofilms at low irradiance, probably driven by self-shading. Horizontal micro-profiles extracted from the O2 images revealed pronounced heterogeneities in local O2 concentration over the base of the epiphytic biofilm, with up to 52% reduction in O2 concentrations in areas with relatively thick (>2 mm), compared with thin (≤1 mm), epiphyte layers in darkness. We also present evidence of enhanced relative internal O2 transport within leaves with epiphyte overgrowth, compared with bare seagrass leaves, in light as a result of limited mass transfer across thick outward diffusion pathways. The local availability of O2 was still markedly reduced in the epiphyte-covered leaves, however. The leaf phyllosphere is thus characterized by a complex microlandscape of O2 availability that strongly affects microbial processes occurring within the epiphytic biofilm, which may have implications for seagrass health, as anoxic microhabitats have been shown to promote the microbiological production of reduced toxic compounds, such as nitric oxide.


Assuntos
Organismos Aquáticos/metabolismo , Hidrobiologia , Nanopartículas de Magnetita , Dispositivos Ópticos , Oxigênio/metabolismo , Folhas de Planta/metabolismo , Eutrofização , Alga Marinha/metabolismo , Zosteraceae/metabolismo
17.
J Biomol Tech ; 31(4): 125-150, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33100918

RESUMO

Unfiltered and filtered water samples can be used to collect environmental DNA (eDNA). We developed the novel "Preserve, Precipitate, Lyse, Precipitate, Purify" (PPLPP) workflow to efficiently extract eDNA from Longmire's preserved unfiltered and filtered water samples (44-100% recovery). The PPLPP workflow includes initial glycogen-aided isopropanol precipitation, guanidium hypochlorite and Triton X-100-based lysis, terminal glycogen-aided polyethylene glycol precipitation, and inhibitor purification. Three novel eDNA assays that exclusively target species invasive to Australia were also developed: Tilapia_v2_16S concurrently targets Oreochromis mossambicus (Mozambique tilapia) and Tilapia mariae (spotted tilapia) while R.marina_16S and C.caroliniana_matK discretely target Rhinella marina (cane toad) and Cabomba caroliniana (fanwort), respectively. All 3 assays were validated in silico before in vitro and in situ validations using PPLPP workflow extracted samples. PPLPP workflow was concurrently validated in vitro and in situ using all 3 assays. In vitro validations demonstrated that 1) glycogen inclusion increased extracellular DNA recovery by ∼48-fold compared with glycogen exclusion, 2) swinging-bucket centrifugation for 90 min at 3270 g is equivalent to fixed-angle centrifugation for 5-20 min at 6750 g, and 3) Zymo OneStep Inhibitor Removal Kit, Qiagen DNeasy PowerClean Pro Cleanup Kit, and silica-Zymo double purification provide effective inhibitor removal. In situ validation demonstrated 95.8 ± 2.8% (mean ± SEM) detectability across all 3 target species in Longmire's preserved unfiltered and filtered water samples extracted using the PPLPP workflow (without phenol:chloroform:isoamyl alcohol purification) after 39 d of incubation at room temperature and 50°C. PPLPP workflow is recommended for future temperate and tropical eDNA studies that use Longmire's to preserve unfiltered or filtered water samples.


Assuntos
Bufo marinus/genética , DNA Ambiental/isolamento & purificação , Monitoramento Ambiental/métodos , Hidrobiologia/métodos , Plantas Daninhas/genética , Preservação Biológica/métodos , Tilápia/genética , Água/análise , Animais , Austrália , Simulação por Computador , Ecossistema , Glicogênio , Espécies Introduzidas , Reação em Cadeia da Polimerase em Tempo Real , Fluxo de Trabalho
18.
Sci Rep ; 10(1): 16536, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024224

RESUMO

Traditional morphological diagnoses of taxonomic status remain widely used while an increasing number of studies show that one morphospecies might hide cryptic diversity, i.e. lineages with unexpectedly high molecular divergence. This hidden diversity can reach even tens of lineages, i.e. hyper cryptic diversity. Even well-studied model-organisms may exhibit overlooked cryptic diversity. Such is the case of the freshwater crustacean amphipod model taxon Gammarus fossarum. It is extensively used in both applied and basic types of research, including biodiversity assessments, ecotoxicology and evolutionary ecology. Based on COI barcodes of 4926 individuals from 498 sampling sites in 19 European countries, the present paper shows (1) hyper cryptic diversity, ranging from 84 to 152 Molecular Operational Taxonomic Units, (2) ancient diversification starting already 26 Mya in the Oligocene, and (3) high level of lineage syntopy. Even if hyper cryptic diversity was already documented in G. fossarum, the present study increases its extent fourfold, providing a first continental-scale insight into its geographical distribution and establishes several diversification hotspots, notably south-eastern and central Europe. The challenges of recording hyper cryptic diversity in the future are also discussed.


Assuntos
Anfípodes/classificação , Anfípodes/genética , Água Doce , Variação Genética , Hidrobiologia , Animais , Código de Barras de DNA Taxonômico , Ecotoxicologia , Europa (Continente) , Evolução Molecular , Ligação Genética , Filogenia
19.
ILAR J ; 60(2): 141-149, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33094818

RESUMO

The use of aquatic animals in ecotoxicology, genetic, and biomedical research has grown immensely in recent years, especially due to the increased use of zebrafish in the laboratory setting. Because water is the primary environment of most aquatic species, the composition and management of this water is paramount to ensuring their health and welfare. In this publication, we will describe the important variables in water quality that can influence animal health and research results, using the zebrafish model for detailed specifics of optimal conditions. Wherever possible, recommendations are provided to reduce the potential impact of poor or highly variable water quality, and standards are given which can be used as institutional goals to maximize animal health and welfare and reduce research variability. It is increasingly important that authors of publications describing work done using aquatic models characterize water quality and other environmental conditions of the animal environment so that the work can be repeated and understood in context of these important factors. It is clear that there are a great many extrinsic factors which may influence research outcomes in the aquatics model laboratory setting, and consequently, an increased level of funding will be essential to support continued research exploring these and other important husbandry conditions. References from a large body of literature on this subject are provided.


Assuntos
Criação de Animais Domésticos/métodos , Animais , Ecossistema , Hidrobiologia , Qualidade da Água , Peixe-Zebra
20.
Sci Rep ; 10(1): 9380, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32523129

RESUMO

Citizen science data (CSD) have the potential to be a powerful scientific approach to assess, monitor and predict biodiversity. Here, we ask whether CSD could be used to predict biodiversity of recently constructed man-made habitats. Biodiversity data on adult dragonfly abundance from all kinds of aquatic habitats collected by citizen scientists (volunteers) were retrieved from the Swedish Species Observation System and were compared with dragonfly abundance in man-made stormwater ponds. The abundance data of dragonflies in the stormwater ponds were collected with a scientific, standardized design. Our results showed that the citizen science datasets differed significantly from datasets collected scientifically in stormwater ponds. Hence, we could not predict biodiversity in stormwater ponds from the data collected by citizen scientists. Using CSD from past versus recent years or from small versus large areas surrounding the stormwater ponds did not change the outcome of our tests. However, we found that biodiversity patterns obtained with CSD were similar to those from stormwater ponds when we restricted our analyses to rare species. We also found a higher beta diversity for the CSD compared to the stormwater dataset. Our results suggest that if CSD are to be used for estimating or predicting biodiversity, we need to develop methods that take into account or correct for the under-reporting of common species in CSD.


Assuntos
Biodiversidade , Ciência do Cidadão/métodos , Odonatos/fisiologia , Animais , Ecossistema , Hidrobiologia/métodos , Lagoas , Prognóstico , Suécia
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