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1.
Parasitology ; 150(9): 769-780, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37246558

RESUMO

Giardiasis, caused by Giardia duodenalis, is a leading cause of diarrhoea in resource-poor countries. To gain a better insight into the epidemiology of Giardia in Africa, we undertook a robust study to comprehend the distribution and prevalence of Giardia infection in humans, animals and their dispersal in the environment. Our protocol was registered with PROSPERO (registration number CRD42022317653). Deep literature search from 5 electronic databases, namely, AJOL, Google scholar, PubMed, ScienceDirect and Springer Link was performed using relevant keywords. Meta-analysis was performed using a random-effects model and heterogeneity among studies was evaluated using Cochran's Q and the I2-statistic. More than 500 eligible studies published from 1 January 1980 until 22 March 2022 were retrieved. In humans, exactly 48 124 Giardia spp. infection cases were registered from the 494 014 stool samples examined resulting in a pooled prevalence estimate (PPE) of 8.8% using microscopy. Whereas copro-antigen tests and molecular diagnostic methods generated PPE of 14.3 and 19.5%, respectively, with HIV+ subjects and those with diarrhoeatic stool having infection rates of 5.0 and 12.3%, respectively. The PPE of Giardia spp. infection in animals using molecular methods was 15.6%, which was most prevalent in pigs (25.2%) with Nigeria registering the highest prevalence at 20.1%. The PPE of Giardia spp. contamination from waterbodies was 11.9% from a total of 7950 samples which were detected using microscopy, with Tunisia documenting the highest infection rate of 37.3%. This meta-analysis highlights the necessity of 'One Health' approach for consolidated epidemiological studies and control of giardiasis in the African continent.


Assuntos
Giardia lamblia , Giardíase , Humanos , Animais , Suínos , Giardíase/epidemiologia , Giardíase/veterinária , Giardíase/diagnóstico , Giardia , Prevalência , Nigéria/epidemiologia , Fezes
2.
Environ Res ; 237(Pt 2): 116936, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37648185

RESUMO

Subsidence waterbodies play an important role in carbon cycle in coal mining area. However, little effort has been made to explore the carbon dioxide (CO2) release characteristics and influencing factors in subsidence waterbodies, especially under different restoration modes. Here, we measured CO2 release fluxes (F(CO2)) across Anguo wetland (AW), louts pond (LP), fishpond (FP), fishery-floating photovoltaic wetland (FFPV), floating photovoltaic wetland (FPV) in coal mining subsidence area, with unrestored subsidence waterbodies (SW) and unaffected normal Dasha river (DR) as the control area. We sampled each waterbody and tested which physical, chemical, and biological characteristics of water and sediment related to variability in CO2. The results indicated that F(CO2) exhibited the following patterns: FFPV > FPV > FP > SW > DR > LP > AW. Trophic lake index (TLI) and microbial biomass carbon content (MBC) in sediment had a positive impact on F(CO2). The dominant archaea Euryarchaeota and Thaumarchaeota, and dominant bacteria Proteobacteria promoted F(CO2). This study can help more accurately quantify CO2 emissions and guide CO2 future emission reduction and subsidence waterbodies estoration.

3.
Mar Drugs ; 21(12)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38132959

RESUMO

Many compounds produced by cyanobacteria act as serine protease inhibitors, such as the tetrapeptides aeruginosins (Aer), which are found widely distributed. The structural diversity of Aer is intriguingly high. However, the genetic basis of this remains elusive. In this study, we explored the genetic basis of Aer synthesis among the filamentous cyanobacteria Planktothrix spp. In total, 124 strains, isolated from diverse freshwater waterbodies, have been compared regarding variability within Aer biosynthesis genes and the consequences for structural diversity. The high structural variability could be explained by various recombination processes affecting Aer synthesis, above all, the acquisition of accessory enzymes involved in post synthesis modification of the Aer peptide (e.g., halogenases, glycosyltransferases, sulfotransferases) as well as a large-range recombination of Aer biosynthesis genes, probably transferred from the bloom-forming cyanobacterium Microcystis. The Aer structural composition differed between evolutionary Planktothrix lineages, adapted to either shallow or deep waterbodies of the temperate climatic zone. Thus, for the first time among bloom-forming cyanobacteria, chemical diversification of a peptide family related to eco-evolutionary diversification has been described. It is concluded that various Aer peptides resulting from the recombination event act in chemical defense, possibly as a replacement for microcystins.


Assuntos
Cianobactérias , Microcystis , Planktothrix , Cianobactérias/genética , Microcistinas/genética , Água Doce , Recombinação Genética
4.
J Environ Manage ; 307: 114503, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35078064

RESUMO

Conserving aquatic resources in the West African Sahel requires water management tools to assess the ecological status of surface water bodies threatened by mounting pressures from agricultural intensification and urbanization. Macroinvertebrate communities of Sahelian rivers were examined to test if a multi-metric index approach could be developed to assess the ecological quality of rivers. A total of 40 sample sites falling within a continuum ranging from "unimpaired reference sites" to "impaired sites" were assessed during this study. Macroinvertebrates were sampled with a hand net following a multi-habitat sampling approach. Key environmental parameters, both physico-chemical and hydro-morphologic, were recorded. More than 20 candidate metrics were evaluated in four categories: composition, functional feeding, diversity, and tolerance. We used detailed analysis procedures to exclude unsuitable metrics from the data set. After excluding redundant metrics, six-core metrics were selected to compose the Sahel River Multimetric Index (SRMI): Total-taxa, Shannon & Weiner index, EPT-taxa, ASPT-NEPBIOS and ASPT-SASS and Collector-filterers. The final index derived from these metrics was divided into five ecological quality classes (high, good, moderate, poor, and bad). The results showed that the SRMI responded to a set of environmental parameters associated with a gradient of human pressures affecting the ecological integrity of water bodies (R2≥|0.50|; p < 0.05; p < 0.001). This work produced a data base and analysis that confirms the usefulness of an unprecedented and promising tool for biological monitoring and decision-making in Sahelian regions' water management.


Assuntos
Monitoramento Ambiental , Rios , Animais , Burkina Faso , Ecossistema , Humanos , Invertebrados
5.
J Environ Manage ; 324: 116263, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36166866

RESUMO

As most cities are located around or near waterbodies, it is essential to assess the thermal effect of these waterbodies. This research focuses on 34 Chinese megacities as case studies to examine the spatial relationship between city-water layout and the thermal effect of waterbodies. Landsat-8 remote-sensing images acquired around noontime in summer were used to retrieve land surface temperatures (LST) and classify land cover. The results show that there are three types of city-water layout. For most cities, waterbodies have a cooling effect, and their mean cooling distance (ΔLmax) ranges from 431 m to 1350 m, with the maximum temperature difference (ΔTmax) ranging from - 2.21 °C to 7.83 °C. The cooling effect of waterbodies is also influenced by their spatial distribution, size, location, and background climate regions. The larger the percentage or area of waterbodies in a city, the shorter ΔLmax and the bigger ΔTmax. Waterbodies have the longest ΔLmax and the smallest ΔTmax when they are dispersed within the city, whereas they have the shortest ΔLmax and the largest ΔTmax when they are flowing through the city. The results suggest that the thermal effects of waterbodies should be seriously considered by urban planners to improve the urban microclimate.


Assuntos
Temperatura Alta , Água , Cidades , Clima , Temperatura , China , Monitoramento Ambiental/métodos
6.
J Helminthol ; 95: e48, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34429177

RESUMO

Helminth infracommunities were studied at 174 sites of Latvia in seven hosts from six amphibian taxa of different taxonomical, ontogenic and ecological groups. They were described using a standard set of parasitological parameters, compared by ecological indices and linear discriminant analysis. Their species associations were identified by Kendall's rank correlation, but relationships with host size and waterbody area were analysed by zero-inflated Poisson and zero-inflated negative binomial regressions. The richest communities (25 species) were found in post-metamorphic semi-aquatic Pelophylax spp. frogs, which were dominated by trematode species of both adult and larval stages. Both larval and terrestrial hosts yielded depauperate trematode communities with accession of aquatic and soil-transmitted nematode species, respectively. Nematode loads peaked in terrestrial Bufo bufo. Helminth infracommunities suggested some differences in host microhabitat or food object selection not detected by their ecology studies. Associations were present in 96% of helminth species (on average, 7.3 associations per species) and dominated positive ones. Species richness and abundances, in most cases, were positively correlated with host size, which could be explained by increasing parasite intake rates over host ontogeny (trematode adult stages) or parasite accumulation (larval Alaria alata). Two larval diplostomid species (Strigea strigis, Tylodelphys excavata) had a negative relationship with host size, which could be caused by parasite-induced host mortality. The adult trematode abundances were higher in larger waterbodies, most likely due to their ecosystem richness, while higher larval abundances in smaller waterbodies could be caused by elevated infection rates under high host densities.


Assuntos
Helmintos , Trematódeos , Animais , Anuros , Ecossistema , Interações Hospedeiro-Parasita , Letônia/epidemiologia
7.
Microb Ecol ; 79(3): 576-587, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31463663

RESUMO

Anthropogenic extreme environments are emphasized as interesting sites for the study of evolutionary pathways, biodiversity, and extremophile bioprospection. Organisms that grow under these conditions are usually regarded as extremophiles; however, the extreme novelty of these environments may have favor adaptive radiations of facultative extremophiles. At the Iberian Peninsula, uranium mining operations have rendered highly polluted extreme environments in multiple locations. In this study, we examined the phytoplankton diversity, community structure, and possible determining factors in separate uranium mining-impacted waters. Some of these human-induced extreme environments may be able to sustain indigenous facultative extremophile phytoplankton species, as well as alleged obligate extremophiles. Therefore, we investigated the adaptation capacity of three laboratory strains, two Chlamydomonas reinhardtii and a Dictyosphaerium chlorelloides, to uranium-polluted waters. The biodiversity among the sampled waters was very low, and despite presenting unique taxonomic records, ecological patterns can be identified. The microalgae adaptation experiments indicated a gradient of ecological novelty and different phenomena of adaptation, from acclimation in some waters to non-adaptation in the harshest anthropogenic environment. Certainly, phytoplankton extremophiles might have been often overlooked, and the ability to flourish in extreme environments might be a functional feature in some neutrophilic species. Evolutionary biology and microbial biodiversity can benefit the study of recently evolved systems such as uranium-polluted waters. Moreover, anthropogenic extremophiles can be harnessed for industrial applications.


Assuntos
Clorófitas/fisiologia , Extremófilos/fisiologia , Fitoplâncton/fisiologia , Urânio/análise , Poluentes Radioativos da Água/análise , Biodiversidade , Chlamydomonas reinhardtii/fisiologia , Chlamydomonas reinhardtii/efeitos da radiação , Clorófitas/efeitos da radiação , Extremófilos/efeitos da radiação , Mineração , Fitoplâncton/efeitos da radiação , Portugal , Espanha
8.
Environ Res ; 189: 109918, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32678742

RESUMO

The cycling of phosphorus (P), iron (Fe) and sulfur (S) in sediments has been previously investigated, but its impacts on the formation of black-odorous waterbodies remains unclear. Here, high-resolution (i.e., 2 mm for P and Fe, and 0.042 mm for S of 2D presentation) simultaneous measurements of P, Fe, and S profiles in river sediments based on the diffusive gradients in thin-films (DGT) technique were conducted in the Pearl River Delta region, South China. Similar distribution trends and significant positive correlations (R = 0.67-0.93, p < 0.01) were observed between Fe and P. Considering the high diffusion fluxes of Fe and P together, it revealed that P release was promoted by the Fe reduction. The two-dimensional labile S profiles showed that their concentrations in sediments were higher by factors of 1.6-20 than those in overlying water. The minor diffusion fluxes of S and the accumulation of acid volatile sulfide indicated that S2- combining with Fe2+ occurred prior to diffusion. Furthermore, the formation mechanisms of black-odorous waterbodies were explored: (i) oxygen depletion by COD and NH4+‒N and large amounts of sulfate input were the main exogenous driving factors. (ii) Reduction of Fe and S to form ferrous sulfide accompanied with P release in sediments were the dominant endogenous causes. These observations together with mechanism analysis can provide a basis for the governance of black-odorous rivers.


Assuntos
Fósforo , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Ferro/análise , Fósforo/análise , Enxofre , Poluentes Químicos da Água/análise
9.
Ecol Lett ; 19(10): 1237-46, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27501082

RESUMO

Combined effects of cumulative nutrient inputs and biogeochemical processes that occur in freshwater under anthropogenic eutrophication could lead to myriad shifts in nitrogen (N):phosphorus (P) stoichiometry in global freshwater ecosystems, but this is not yet well-assessed. Here we evaluated the characteristics of N and P stoichiometries in bodies of freshwater and their herbaceous macrophytes across human-impact levels, regions and periods. Freshwater and its macrophytes had higher N and P concentrations and lower N : P ratios in heavily than lightly human-impacted environments, further evidenced by spatiotemporal comparisons across eutrophication gradients. N and P concentrations in freshwater ecosystems were positively correlated and N : P was negatively correlated with population density in China. These results indicate a faster accumulation of P than N in human-impacted freshwater ecosystems, which could have large effects on the trophic webs and biogeochemical cycles of estuaries and coastal areas by freshwater loadings, and reinforce the importance of rehabilitating these ecosystems.


Assuntos
Ecossistema , Água Doce , Atividades Humanas , Nitrogênio/química , Fósforo/química , China , Poluentes Químicos da Água , Poluição da Água
10.
Sci Total Environ ; 942: 173467, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38802007

RESUMO

Stormwater ponds are increasingly becoming a dominant pond type in cities experiencing urban sprawl. These human-made ponds are designed primarily to control flooding issues associated with increased impervious surface in cities and serve to retain sediment and contaminants before flowing to urban downstream waterways. Along with these important functions, constructed ponds including stormwater ponds may be critical in urban freshwater conservation because they often represent some of the few remaining lentic environments (still water; e.g. ponds, wetlands, lakes) in many cities. We currently lack a clear understanding of the role that stormwater ponds play in serving as habitat for freshwater biodiversity. Here, we examined whether stormwater ponds support freshwater biodiversity in cities by reviewing the empirical literature on biotic community responses in urban stormwater ponds across a range of taxonomic groups. We conducted a meta-analysis on empirical papers that quantitatively examined differences in taxonomic richness between stormwater ponds and reference ponds (n = 11 papers, 22 effects). We also examined a broader set of 58 papers to qualitatively synthesize studies on stormwater pond communities and assess various indicators of habitat quality in stormwater ponds. In the studies examined, heterogeneity exists in the habitat quality of stormwater ponds and increased pollutant loads are often reported. However, the results highlight that stormwater ponds tend to contain alpha diversity comparable to reference ponds, and that overall, a range of ecologically important wildlife make use of and inhabit urban stormwater ponds. We find that stormwater ponds can often support communities with broad compositions of taxa, including those that are sensitive or vulnerable to environmental change. We compile recommendations provided within the studies in order to improve our understanding of the management of urban stormwater ponds for biodiversity conservation.


Assuntos
Biodiversidade , Ecossistema , Água Doce , Lagoas , Conservação dos Recursos Naturais/métodos , Áreas Alagadas , Animais , Cidades
11.
Top Cogn Sci ; 15(3): 560-583, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37078233

RESUMO

Landscapes are essential to human life: they provide a multitude of material (food, water, pollination) and nonmaterial (beauty, tranquility, recreation) values. Their importance is enshrined in international conventions and treaties, committing signatories to protecting, monitoring, and managing all landscapes. Yet, relatively little is known about how people conceptualize "landscape" and its constituents. There is emerging evidence that conceptualizations of landscape entities may influence landscape management. This in turn raises the question as to how people speaking different languages, and with differing levels of expertise, may differ in conceptualizing landscape domains as a whole. In this paper, we investigated how people conceptualize landscape-related terms in a specific domain-waterbodies-by comparing German and English-speaking experts and nonexperts. We identified commonly used waterbody terms in sustainability discourses in both languages, and used those terms to collect sensory, motor, and affective ratings from participants. Speakers of all groups appear to conceptualize the domain of waterbody terms in comparable ways. Nevertheless, we uncovered subtle differences across languages for nonexperts. For example, there were differences in which waterbodies were associated with calm happiness in each language. In addition, olfaction seemingly plays a role in English speakers' conceptualization of waterbodies, but not German speakers. Taken together, this suggests the ways in which people relate to landscape although shared in many respects may also be shaped in part by their specific language and culture.


Assuntos
Formação de Conceito , Idioma , Humanos , Emoções
12.
Sci Total Environ ; 888: 164300, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37211111

RESUMO

Small waterbodies such as ponds are widely represented in cities, contributing to the blue-green infrastructure, improving human well-being. Ornamental ponds are particularly abundant in the densest urbanized areas, especially in parks, in private grounds such as gardens and also imbedded in the green infrastructure. However, their multifunctionality remains infrequent, as generally aesthetic enjoyment is the main ecosystem service targeted. The promotion of native biodiversity is rarely a priority, as are other ecosystem services (e.g. flood mitigation or water purification). It is nevertheless questionable if such mono-functional ponds could also be able to provide other services. Indeed, an innovative approach would be to increase the multifunctionality of ornamental ponds, especially for biodiversity. This was investigated in 41 ornamental ponds designed for providing aesthetic enjoyment in the city of Geneva (Switzerland). The biodiversity was assessed, as well as selected ecosystem services (water retention, phytopurification, cooling effect, carbon sequestration). A survey among the population was also conducted. This survey underlined a recognized contribution of ornamental ponds to well-being. However, the assessment of the ecosystem services evidenced a lack of multifunctionality for most of these ponds. They presented a low biodiversity, compared to more natural ponds and to unimpaired ponds. Furthermore, they performed poorly for most other ecosystem services investigated. There were nevertheless exceptions, with selected ponds displaying a multifunctionality, even for ecosystem services for which they were not designed. It was also shown that ornamental ponds could easily be optimized for biodiversity by simple low-cost management measures. Additional ecosystem services could also be promoted. The performance of small ornamental ponds is best when ponds are considered collectively, as pondscapes, with their cumulative benefits. New ornamental pond implementation is therefore encouraged, as their multifunctionality turns them into Nature-based Solutions able to contribute to solving several societal challenges and to improve human well-being.


Assuntos
Ecossistema , Lagoas , Humanos , Cidades , Biodiversidade , Jardins
13.
Eco Environ Health ; 1(1): 46-52, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38078199

RESUMO

Fish consumption is the primary dietary route of human exposure to methylmercury. It has been well documented that elevated mercury concentration in fish in North America and Europe is linked to anthropogenic mercury emissions. China is the world's largest producer, consumer, and emitter of mercury, as well as the world's largest commercial fish producer and consumer. Although mercury pollution in fish in China is currently receiving much attention worldwide, its status remains largely unknown. Here, we conducted a meta-analysis on total mercury concentrations in marine and freshwater fish samples, covering 35,464 samples collected in China over the past 30 years. It is found that, opposite to the increasing emission and documented mercury contamination events, mercury levels in fish have gradually decreased in China over the past 30 years. The results were in sharp contrast to those found in North America and Europe. The mercury concentrations in fish were significantly anticorrelated with the fish catch and fish aquaculture and were inverse to trophic levels. Overfishing and the short lifecycle of aquaculture fish, both reducing the trophic level and the duration of mercury accumulation, were the most likely causes leading to the decline of mercury concentrations found in fish in China.

14.
Microorganisms ; 10(3)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35336075

RESUMO

The Tatun Volcanic Group (TVG), located in northern Taiwan, is characterized by acidic hot springs where the outflow of the hot springs may affect the properties of the associated lotic water bodies. We investigated the bacterial diversity and functional profiles of the Peihuang (PHC), HuangGang (HGC), and Nanhuang Creeks (NHC) located in the TVG basin using 16S rRNA gene sequencing coupled with statistical analyses. Water samples were collected from various streams of the creeks for two months of the year. The NHC showed the highest diversity, richness, and a unique number of phyla, which was followed by the HGC. A reduced number of phyla and a lower diversity was noticed in the PHC. The NHC was found to be abundant in the genera Armatimonas, Prosthecobacter, Pirellula, and Bdellovibrio, whereas the HGC was rich in Thiomonas, Acidiphilium, Prevotella, Acidocella, Acidithiobacillus, and Metallibacterium. The PHC was abundant in Thiomonsa, Legionella, Acidocella, and Sulfuriferula. The samples did not show any strong seasonal variations with the bacterial diversity and abundance; however, the relative abundance of each sampling site varied within the sampling months. The iron transport protein- and the sulfur metabolism-related pathways were predicted to be the key functions in all the creeks, whereas the heavy metal-related functions, such as the cobalt/nickel transport protein and the cobalt-zinc-cadmium efflux system were found to be abundant in the HGC and PHC, respectively. The abundance of Bdellovibrio in the NHC, Diplorickettsia in the HGC, and Legionella in the PHC samples indicated a higher anthropogenic impact over the creek water quality. This study provides the data to understand the distinct bacterial community structure, as well as the functional potentials of the three major watersheds, and helps the knowledge of the impact of the physicochemical properties of the TVG hot springs upon the watersheds.

15.
Ecol Evol ; 12(3): e8636, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35342565

RESUMO

In many farming landscapes, aquatic features, such as wetlands, creeks, and dams, provide water for stock and irrigation, while also acting as habitat for a range of plants and animals. Indeed, some species threatened by land-use change may otherwise be considerably rarer-or even suffer extinction-in the absence of these habitats. Therefore, a critical issue for the maintenance of biodiversity in agricultural landscapes is the extent to which the management of aquatic systems can promote the integration of agricultural production and biodiversity conservation. We completed a cross-sectional study in southern New South Wales (southeastern Australia) to quantify the efficacy of two concurrently implemented management practices-partial revegetation and control of livestock grazing-aimed at enhancing the vegetation structure, biodiversity value, and water quality of farm dams. We found that excluding livestock for even short periods resulted in increased vegetation cover. Relative to unenhanced dams (such as those that remained unfenced), those that had been enhanced for several years were characterized by reduced levels of turbidity, nutrients, and fecal contamination. Enhanced dams also supported increased richness and abundance of macroinvertebrates. In contrast, unenhanced control dams tended to have high abundance of a few macroinvertebrate taxa. Notably, differences remained between the macroinvertebrate assemblages of enhanced dams and nearby "natural" waterbodies that we monitored as reference sites. While the biodiversity value of semilotic, natural waterbodies in the region cannot be replicated by artificial lentic systems, we consider the extensive system of farm dams in the region to represent a novel ecosystem that may nonetheless support some native macroinvertebrates. Our results show that management interventions such as fencing and grazing control can improve water quality in farm dams, improve vegetation structure around farm dams, and support greater abundance and diversity of aquatic macroinvertebrates.

16.
Sci Total Environ ; 851(Pt 1): 158096, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-35987216

RESUMO

Harmful algal blooms (HABs) are an issue of concern for water management worldwide. As such, effective monitoring strategies of HAB spatio-temporal variability in waterbodies are needed. Remote sensing has become an increasingly important tool for HAB detection and monitoring in large lakes. However, accurate HAB detection in small-medium waterbodies via satellite data remains a challenge. Current barriers include the waterbody size, the limited freely available high resolution satellite data, and the lack of field calibration data. To test the applicability of remote sensing for detecting HABs in small-medium waterbodies, three satellites (Planetscope, Sentinel-2 and Landsat-8) were used to understand how spatial resolution, the availability of spectral bands, and the waterbody size itself effect HAB detection skill. Different algorithms and a non-parametric method, Self-Organizing Map (SOM), were tested. Curvature Around Red and NIR minus Red had the best HAB detection skill of the 20 existing algorithms that were tested. Landsat 8 and Sentinel 2 were the best satellites for HAB detection in small to medium waterbodies. The most critical attribute for detecting HABs were the available satellite bands, which determine the detection algorithms that can be used. Importantly, algorithm performance was mostly unrelated to waterbody size. However, there remain some barriers in utilizing satellite data for HAB detection, including algae dynamics, macrophyte cover within the waterbody, weather effects, and the correction models for satellite data. Moreover, it is important to consider the match time between satellite overpass and sampling activities for calibration. Given these challenges, integrating regular sampling activities and remote sensing is recommended for monitoring and managing small-medium waterbodies.


Assuntos
Proliferação Nociva de Algas , Tecnologia de Sensoriamento Remoto , Lagos , Tecnologia de Sensoriamento Remoto/métodos
17.
Ecohealth ; 19(2): 259-272, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35759112

RESUMO

In Côte d'Ivoire, rubber cultivation has more than doubled since 2010. These mass agricultural areas require a large workforce with little information on how this environment might impact risk of mosquito-borne diseases. The objective of this study was to assess the larval ecology of mosquitoes in rubber areas of Dabou, Côte d'Ivoire. From January to June 2017, an entomological survey was conducted of mature (MP) and immature (IP) rubber plantations, as well as in villages surrounded by rubber plantations (SV) and remote from rubber plantations (RV). The number and type of potential and positive breeding sites were recorded, and mosquito larval densities and diversity were estimated. Seven genera divided into 31 species including major vector such as Anopheles gambiae s.l. and Aedes aegypti were identified. A total of 1,660 waterbodies were identified with a larvae positivity rate of 63.1%. A majority of waterbodies were identified in SV (N = 875, 53.4% positivity rate), followed by MP (N = 422, 81.8% positivity rate), IP (N = 194, 72.2% positivity rate) and least in RV (N = 169, 57.4% positivity rate). The most important breeding sites for disease vectors were leaf axils in IP (N = 108, 77.1%), latex collection cups in MP (N = 332, 96.2%) and the containers abandoned in the SV (N = 242, 51.8%) as well as in the RV (N = 59, 60.8%). All these results allow us to affirm that the cultivation of rubber trees has an impact on the larval ecology by increasing the number of available sites and favoring a high larval density and diversity.


Assuntos
Anopheles , Culicidae , Animais , Côte d'Ivoire , Larva , Mosquitos Vetores , Melhoramento Vegetal , Borracha
18.
Sci Total Environ ; 806(Pt 4): 150897, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34653464

RESUMO

With the effects of global warming becoming ever more obvious, biodiversity conservation is facing severe challenges. Currently, a deeper understanding the mechanisms of the effects of warming on sensitive species has become an important topic in aquatic biodiversity and ecological management. Our study first overcame the "challenge" for a sensitive indicator species (Netzelia tuberspinifera, an endemic testate amoeba species in East Asia) of culturing under laboratory conditions, and then explored its molecular response mechanisms to warming using transcriptomic analysis. Our data indicate that temperature mainly drove the geographical and seasonal variation of N. tuberspinifera populations. Transcriptomic results indicate that when the temperature is <25 °C, rising temperature triggers the biosynthesis of ribosomes; while the temperature is >25 °C, it triggers molecular processes related with cell division, test formation and general biomass increase. However, once the temperature exceeds 40 °C, N. tuberspinifera is unable to survive. Following from these results, the distribution of N. tuberspinifera might expand towards higher altitude or latitude regions under global warming. For the first time, our study showed direct evidence for sensitive protozoa species that presents a very narrow adaptation mechanism to local climate. Our work provides fundamental data for regional biodiversity conservation and scientific reference in subtropical and tropical waterbodies.


Assuntos
Amoeba , Biodiversidade , Clima , Ásia Oriental , Aquecimento Global , Temperatura
19.
Data Brief ; 41: 107934, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35242916

RESUMO

This dataset was obtained over repeated field-trips to the Sierra Nevada Massif and contains the physical parameters of its recognised water-bodies. It therefore defines the general cartography of the area, with data on individual features regarding the geographical coordinates (x, y, z), dimensions (length, width, depth), flooded surface area, stored water volume, shoreline length, as well as the area of associated green fringes and the length of their borders. These data were basically obtained using straightforward techniques, such as GPS, tape measurements and photographic interpretation. The data were then previously used to define the role of these water-bodies in the hydrology of the massif: relationships between number of water-bodies and water volumes between 2700 and 3200 m a.s.l. regarding watersheds (Mediterranean, Atlantic and total massif), relationships with green fringes, moment of maximum snowmelt discharge and the estimation of different components of water volumes discharged during the main period of thaw. The formation patterns of each water-body were also identified in their situational context, and the role played by each formation process on the stored water volume: the water-bodies close to the peak line (2918 m mean altitude) are highly dependant on the glacial processes that created the hollows in which they are located. Slope instability created water-bodies mainly located at lower altitudes and are more fragile due intense slope dynamics. In any case, these hydrological data show a paradoxical behaviour because despite its higher xericity, the Mediterranean watershed generally has higher water contents than the Atlantic. The cause of this hydrological imbalance between watersheds seems to be unrelated to the formation processes of the existing water-bodies. Sierra Nevada is considered to be clearly representative of a high mountain Mediterranean environment, where the data collected are a starting point to define the different habitats or for investigation of the hydrological processes of the massif and their evolution. Lack of such data is often a problem that in the present case is solved with this contribution.

20.
PeerJ ; 9: e12103, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34557354

RESUMO

Small waterbodies are a unique aquatic ecosystem with an increasing recognition for their important role in maintaining regional biodiversity and delivering ecosystem services. However, small waterbodies in Northwest Yunnan, one of the most concerned global biodiversity hot-spots, remain largely unknown. Here, we investigated the community structure of crustacean zooplankton and their relationships with limnological, morphometric and spatial variables in the highland small waterbodies in Northwest Yunnan in both the dry (October 2015) and rainy (June 2016) seasons. A total of 38 species of crustacean zooplankton were identified in our study, which is significantly higher than many other reported waterbodies in the Yunnan-Guizhou plateau as well as in the Yangtze River basin. This suggests that the highland small waterbodies are critical in maintaining regional zooplankton diversity in Northwest Yunnan. Meanwhile, we found limnological variables could explain most variation of crustacean zooplankton community, comparing to the morphometric and spatial variables in both the rainy and dry seasons. Our study revealed the diversity and community structure of crustacean zooplankton in the highland small waterbodies in Northwest Yunnan and highlighted the importance of small waterbodies in maintaining regional biodiversity.

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