Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.796
Filtrar
1.
Aquat Toxicol ; 227: 105595, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32911330

RESUMO

In order to understand the potential impacts of nickel nanowires (Ni NWs) after reaching the aquatic environment, this research evaluated the toxicity of Ni NWs with different lengths (≤ 1.1, ≤11 and ≤ 80 µm) for several floating, planktonic and nektonic freshwater organisms. In this work, Ni NWs were synthesized by electrodeposition using anodized aluminum oxide (AAO) membranes. The toxicity of the NWs was assessed using a battery of aquatic species representative of key functions at the ecosystem level: the bacterium Aliivibrio fischeri, the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the crustacean Daphnia magna and the zebrafish Danio rerio. Results indicated that for the concentrations tested (up to 2.5 mg L-1) the synthesized Ni NWs showed low toxicity. And although no lethal toxicity was observed for D. magna, at a sublethal level the feeding activity of the freshwater cladoceran was severely affected after exposure to Ni NWs. These findings showed that NWs can be accumulated in the gut of D. magna, even during a short exposure (24 h) directly impairing Daphnia nutrition and eventually populations growth. Consequently, this can also contribute to trophic transfer of NWs along the food chain. According to our results the toxicity of Ni NW may be mainly attributed to physical effects rather than chemical effects of Ni ions, considering that the concentrations of Ni NWs tested in this study were well below the toxicity thresholds reported in the literature for Ni ions and for Ni NMs.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanofios/toxicidade , Níquel/toxicidade , Purificação da Água/métodos , Aliivibrio fischeri , Animais , Clorofíceas , Daphnia/efeitos dos fármacos , Ecossistema , Cadeia Alimentar , Água Doce , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
2.
Aquat Toxicol ; 227: 105620, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32932042

RESUMO

The 20th Pollutant Responses in Marine Organisms (PRIMO 20) conference provided a forum for scientists from around the world to communicate novel toxicological research findings specifically focused on aquatic organisms, by combining applied and basic research at the intersection of environmental and mechanistic toxicology. The work highlighted in this special issue of Aquatic Toxicology, a special issue of Marine Environmental Research, and presented through posters and presentations, encompass important and emerging topics in freshwater and marine toxicology. This includes multiple types of emerging contaminants including microplastics and UV filtering chemicals. Other studies aimed to further our understanding of the effects of endocrine disrupting chemicals, pharmaceuticals, and personal care products. Further research presented in this virtual issue examined the interactive effects of chemicals and pathogens, while the final set of manuscripts demonstrates continuing efforts to combine traditional biomonitoring, data from -omic technologies, and modeling for use in risk assessment and management. An additional goal of PRIMO meetings is to address the link between environmental and human health. Several articles in this issue of Aquatic Toxicology describe the appropriateness of using aquatic organisms as models for human health, while the keynote speakers, as described in the editorial below, presented research that highlighted bioaccumulation of contaminants such as PFOS and mercury from fish to marine mammals and coastal human populations such as the Gullah/GeeChee near Charleston, South Carolina, USA.


Assuntos
Organismos Aquáticos/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Disruptores Endócrinos , Monitoramento Ambiental , Poluentes Ambientais/farmacologia , Peixes , Água Doce , Humanos , Plásticos
3.
Bull Environ Contam Toxicol ; 105(4): 530-537, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32940716

RESUMO

An increase in the production and usage of gold nanoparticles (AuNPs) triggers the necessity to focus on their impact on ecosystems. Therefore, the purpose of this study was to investigate the acute toxicity of AuNPs and ionic gold (Au (III)) to organisms representing all trophic levels of the aquatic ecosystem, namely producers (duckweed Lemna minor), consumers (crustacean Daphnia magna, embryos of Danio rerio) and decomposers (bacteria Vibrio fischeri). The organisms were exposed according to a standardized protocol for each species and endpoints. The AuNPs (1.16 and 11.6 d.nm) were synthesized using citrate (CIT) and polyvinylpyrrolidone (PVP) as capping agents, respectively. It was found, that Au (III) was significantly more toxic than AuNPs PVP and AuNPs CIT. AuNPs showed significant toxicity only at high concentrations (mg/L), which are not environmentally relevant in the present time, but a cautious approach is advised, due to the possibility of interactions with other contaminants.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Araceae/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Ouro/toxicidade , Íons/toxicidade , Nanopartículas Metálicas/toxicidade , Peixe-Zebra , Animais , Organismos Aquáticos , Daphnia/embriologia , Relação Dose-Resposta a Droga , Embrião não Mamífero/efeitos dos fármacos , Testes de Toxicidade Aguda
4.
Mar Environ Res ; 160: 105019, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32907733

RESUMO

Polycyclic musk compounds have been identified in environmental matrices (water, sediment and air) and in biological tissues in the last decade, yet only minimal attention has been paid to their chronic toxicity in the marine environment. In the present research, the clams Ruditapes philippinarum were exposed to 0.005, 0.05, 0.5, 5 and 50 µg/L of the fragrances Galaxolide® (HHCB) and Tonalide® (AHTN) for 21 days. A battery of biomarkers related with xenobiotics biotransformation (EROD and GST), oxidative stress (GPx, GR and LPO) and genotoxicity (DNA damage) were measured in digestive gland tissues. HHCB and AHTN significantly (p < 0.05) induced EROD and GST enzymatic activities at environmental concentrations. Both fragrances also induced GPx activity. All concentrations of both compounds induced an increase of LPO and DNA damage on day 21. Although these substances have been reported as not acutely toxic, this study shows that they might induce oxidative stress and genotoxicity in marine organisms.


Assuntos
Benzopiranos , Dano ao DNA , Ácidos Graxos Monoinsaturados , Estresse Oxidativo , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Benzopiranos/toxicidade , Ácidos Graxos Monoinsaturados/toxicidade , Tetra-Hidronaftalenos , Poluentes Químicos da Água/toxicidade
5.
Chemosphere ; 258: 127435, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947671

RESUMO

Isotopic composition of mercury (Hg) in marine organisms and sediment cores was used to identify sources and reconstruct historical trends of contamination in the coastal-marine area of Rosignano Solvay (Italy), affected by Hg pollution from a chlor-alkali plant on the near land. Sediments show a wide range of Hg concentration and Hg isotope signatures. Particularly, coupled Hg concentration and δ202Hg values trace inputs from different sources. The two depth-profiles clearly indicate three distinct periods: "pre-industrial" (before 1941), "industrial" (between 1941 and 2007) and "post-industrial" (after 2007) ages. This is also corroborated by sediment chronology, using 210Pb dating method, validated through 137Cs. Marine organisms are characterized by Hg isotope signatures comparable to "post-industrial" surface sediments. Notably, specimens of Mullus spp. evidence isotope composition comparable to the "industrial" sediments, thus suggesting a still active role of those sediments as source of Hg for the benthic fish compartment. The small amount of MIF and the Δ199Hg/Δ201Hg ratio recorded in organisms are reasonably consistent with limited processes of MMHg demethylation in the water column.


Assuntos
Mercúrio/análise , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos , Monitoramento Ambiental , Poluição Ambiental , Peixes , Sedimentos Geológicos , Indústrias , Isótopos , Itália , Isótopos de Mercúrio/análise
6.
SAR QSAR Environ Res ; 31(10): 785-801, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32878491

RESUMO

Reviewing the toxicological literature for over the past decades, the key elements of QSAR modelling have been the mechanisms of toxic action and chemical classes. As a result, it is often hard to design an acceptable single model for a particular endpoint without clustering compounds. The main aim here was to develop a Pass-Pass Quantitative Structure-Activity-Activity Relationship (PP QSAAR) model for direct prediction of the toxicity of a larger set of compounds, combing the application of an already predicted model for another species, and molecular descriptors. We investigated a large acute toxicity data set of five aquatic organisms, fish, Daphnia magna, and algae from the VEGA-Hub, as well as Tetrahymena pyriformis and Vibrio fischeri. The statistical quality of the models encouraged us to consider this alternative for the prediction of toxicity using interspecies extrapolation QSAAR models without regard to the toxicity mechanism or chemical class. In the case of algae, the use of activity values from a second species did not improve the models. This can be attributed to the weak interspecies relationships, due to different aquatic toxicity mechanisms in species.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Animais , Daphnia/efeitos dos fármacos , Peixes , Regulamentação Governamental , Microalgas/efeitos dos fármacos , Modelos Químicos , Medição de Risco , Tetrahymena pyriformis/efeitos dos fármacos
7.
Aquat Toxicol ; 227: 105569, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32916319

RESUMO

Pharmaceuticals are widespread contaminants across the aquatic systems and despite the role that these compounds play in society today, little is known about their effects in aquatic organisms once they are released into the environment. This study aims to provide quantitative insight on the effects of antidepressants on the reproduction of fish and crustaceans with a multilevel meta-analysis. A systematic literature search identified 19 studies investigating effects of antidepressant exposure in fish or crustaceans' reproduction, according to specific selection criteria. Heterogeneity analysis was performed and the moderating effect of the range of exposure concentrations, exposure time, organism group and toxicant was tested. Additionally, publication bias was also addressed. The results showed that, overall, there is no significant association between antidepressant exposure and the reproduction of fish and crustaceans, however, moderator analysis revealed that the range of concentrations is a significant moderator for fish and crustacean fecundity, showing contrary results between the two groups. Antidepressant concentration had a small, yet positive effect on fish fecundity, meaning that increased concentrations resulted in increased fish fecundity, whilst a negative effect on crustaceans' fecundity was apparent with increasing concentrations. This difference could be related to data artifacts, or, more likely, evidencing a hormetic dose-response curve, with different ranges of exposure concentrations considered in studies on fish and crustaceans. Antidepressants have shown effects on reproductive outcomes in aquatic organisms, based on individual studies and narrative reviews. However, our results show that other factors can have an important role. Additionally, data available for a quantitative assessment is scarce, focusing mainly on a few freshwater species, low concentration ranges and one SSRI compound, fluoxetine. Thus, more research on the subject is needed since meta-analysis are only as statistically powerful as the number of, good quality, studies they include.


Assuntos
Antidepressivos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Fluoxetina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/fisiologia , Crustáceos/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Água Doce/química , Reprodução/efeitos dos fármacos
8.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(4): 426-427, 2020 Apr 07.
Artigo em Chinês | MEDLINE | ID: mdl-32935523

RESUMO

OBJECTIVE: To understand the situation of Anisakis infection of in market-available marine fish in Dongtai City, so as to provide the evidence for the assessment of the risk of human Anisakis infections. METHODS: Raw and fresh marine fish caught in the sea of Dongtai City for sale were collected in 2018. The fish were weighted and dissected for the identification of Anisakis, and the prevalence and intensity of Anisakis infections were calculated. In addition, the correlation between the weight of Anisakis-infected marine fish and the infection intensity of Anisakis was examined. RESULTS: There were four species of marine fish infected with Anisakis, including Trichiurus haumela, Scomberomorus niphonius, Pneumatophorus japonicus and Larimichthys polyactis. Among the 149 fish samples, there were 78 with Anisakis infections, with a prevalence rate of 52.35%. The prevalence of Anisakis infection was 100.00% (28/28), 30.00% (9/30), 0 (0/30), 53.33% (16/30) and 80.65% (25/31) in T. haumela, S. niphonius, cuttle fish, P. japonicus and L. polyactis, respectively. A total of 1 049 Anisakis worms were collected, and the overall intensity of infection was 13.45 worms per fish. Spearman correlation analysis showed a positive correlation between the weight of T. haumela and the intensity of Anisakis infection (rs = 0.38, P = 0.047), and no correlation was found in other fish species. CONCLUSIONS: There is a high rate of Anisakis infection in marine fish along the offshore areas of Dongtai City. Intensification of health education is required and healthy and safe dietary habits are encouranged.


Assuntos
Anisaquíase , Anisakis , Doenças dos Peixes , Peixes , Parasitologia de Alimentos , Animais , Anisaquíase/epidemiologia , Anisakis/fisiologia , Organismos Aquáticos/parasitologia , Peso Corporal , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Parasitologia de Alimentos/estatística & dados numéricos , Carga Parasitária/estatística & dados numéricos
9.
Sci Total Environ ; 739: 140261, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758962

RESUMO

The accumulation of anthropogenic chemical substances in aquatic organisms is an immensely important issue from the point of view of environmental protection. In the context of the increasing number and variety of compounds that may potentially enter the environment, there is a need for efficient and reliable solutions to assess the risks. However, the classic approach of testing with fish or other animals is not sufficient. Due to very high costs, significant time and labour intensity, as well as ethical concerns, in vivo methods need to be replaced by new laboratory-based tools. So far, many models have been developed to estimate the bioconcentration potential of chemicals. However, most of them are not sufficiently reliable and their predictions are based on limited input data, often obtained with doubtful quality. The octanol-water partition coefficient is still often used as the main laboratory tool for estimating bioconcentration. However, according to current knowledge, this method can lead to very unreliable results, both for neutral species and, above all, for ionic compounds. It is therefore essential to start using new, more advanced and credible solutions on a large scale. Over the last years, many in vitro methods have been newly developed or improved, allowing for a much more adequate estimation of the bioconcentration potential. Therefore, the aim of this work was to review the most recent laboratory methods for assessing the bioconcentration potential and to evaluate their applicability in further research.


Assuntos
Organismos Aquáticos , Poluentes Químicos da Água/análise , Animais , Bioacumulação , Peixes , Xenobióticos
10.
PLoS One ; 15(8): e0236077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780731

RESUMO

As aquatic invasive species (AIS) proliferate worldwide, a better understanding of their roles in invaded habitats is needed to inform management and introduction prevention strategies and priorities. Metabarcoding of stomach content DNA (scDNA) shows considerable promise in such regard. We thus metabarcoded scDNA from two non-native fish species (alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax)), and three native ones (bloater (Coregonus hoyi), ninespine stickleback (Pungitius pungitius), and slimy sculpin (Cottus cognatus)). Fishes (N = 376) were sampled in spring 2009 and 2010 from 73-128 m depths at three Lake Michigan sites. Four mitochondrial cytochrome oxidase 1 (CO1) primer sets designed to target five potential AIS prey, and a universal aquatic invertebrate CO1 primer set targeting both native and AIS prey were used. Quality controlled prey amplicons were matched to three AIS prey: Bythotrephes longimanus (mean percent frequency occurrence, all samples = 7%), Cercopagis pengoi (5%), and Dreissena rostriformis bugensis (11%). Neither invasive prey Dreissena polymorpha nor Hemimysis anomala were detected. Native prey Leptodiaptomus sicilis, Limnocalanus macrurus, and Mysis diluviana were relatively common in scDNA (respective mean percent occurrences, all samples: 48%, 25%, 42%). Analysis of variation in prey occurrences for sample site, predator species, sample year, sample depth, and predator total length (TL) indicated site and predator species were most important. However, B. longimanus occurrence in scDNA depended upon predator TL, perhaps indicative of its unique defensive spine limiting susceptibility to predation until fishes exceed species-specific gape-based limitations. Our analysis of native and invasive prey species indicated possible indirect AIS impacts such as native predators switching their diet due to AIS-driven losses of preferred native prey. Metabarcoding demonstrated that AIS are integrated components of the offshore Lake Michigan food web, with both native and non-native predators, and both invasive and native prey are affecting species interactions across multiple trophic levels.


Assuntos
Organismos Aquáticos/genética , Peixes/fisiologia , Preferências Alimentares , Espécies Introduzidas , Invertebrados/genética , Animais , Organismos Aquáticos/isolamento & purificação , Código de Barras de DNA Taxonômico , Cadeia Alimentar , Conteúdo Gastrointestinal , Lagos , Michigan , Comportamento Predatório , Wisconsin
11.
PLoS One ; 15(8): e0236246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804956

RESUMO

K+ is an essential nutrient for plant growth and is responsible for many important physiological processes. K+ deficiency leads to crop yield losses, and overexpression of K+ transporter genes has been proven to be an effective way to resolve this problem. However, current research on the overexpression of K+ transporter genes is limited to plant sources. TrkH is a bacterial K+ transporter whose function generally depends on the regulation of TrkA. To date, whether TrkH can improve K+ uptake in eukaryotic organisms is still unknown. In this study, a novel MbtrkH gene was cloned from marine microbial metagenomic DNA. Functional complementation and K+-depletion analyses revealed that MbTrkH functions in K+ uptake in the K+-deficient yeast strain CY162. Moreover, K+-depletion assays revealed that MbtrkH overexpression improves plant K+ uptake. K+ hydroponic culture experiments showed that, compared with WT tobacco lines, MbtrkH transgenic tobacco lines had significantly greater fresh weights, dry weights and K+ contents. These results indicate that MbTrkH promotes K+ uptake independently of TrkA in eukaryotes and provide a new strategy for improving K+-use efficiency in plants.


Assuntos
Organismos Aquáticos/genética , Potássio/metabolismo , Saccharomyces cerevisiae/metabolismo , Água do Mar/microbiologia , Tabaco/metabolismo , Clonagem Molecular , Metagenoma , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Canais de Potássio/genética , Canais de Potássio/metabolismo , Saccharomyces cerevisiae/genética , Tabaco/genética
12.
PLoS One ; 15(7): e0220353, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735579

RESUMO

The introduction and establishment of nonindigenous species (NIS) through global ship movements poses a significant threat to marine ecosystems and economies. While ballast-vectored invasions have been partly addressed by some national policies and an international agreement regulating the concentrations of organisms in ballast water, biofouling-vectored invasions remain largely unaddressed. Development of additional efficient and cost-effective ship-borne NIS policies requires an accurate estimation of NIS spread risk from both ballast water and biofouling. We demonstrate that the first-order Markovian assumption limits accurate modeling of NIS spread risks through the global shipping network. In contrast, we show that higher-order patterns provide more accurate NIS spread risk estimates by revealing indirect pathways of NIS transfer using Species Flow Higher-Order Networks (SF-HON). Using the largest available datasets of non-indigenous species for Europe and the United States, we then compare SF-HON model predictions against those from networks that consider only first-order connections and those that consider all possible indirect connections without consideration of their significance. We show that not only SF-HONs yield more accurate NIS spread risk predictions, but there are important differences in NIS spread via the ballast and biofouling vectors. Our work provides information that policymakers can use to develop more efficient and targeted prevention strategies for ship-borne NIS spread management, especially as management of biofouling is of increasing concern.


Assuntos
Organismos Aquáticos/fisiologia , Espécies Introduzidas , Incrustação Biológica , Análise por Conglomerados , Medição de Risco , Navios
13.
Nature ; 584(7819): 82-86, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760046

RESUMO

Marine heatwaves (MHWs)-discrete but prolonged periods of anomalously warm ocean temperatures-can drastically alter ocean ecosystems, with profound ecological and socioeconomic impacts1-8. Considerable effort has been directed at understanding the patterns, drivers and trends of MHWs globally9-11. Typically, MHWs are characterized on the basis of their intensity and persistence at a given location-an approach that is particularly relevant for corals and other sessile organisms that must endure increased temperatures. However, many ecologically and commercially important marine species respond to environmental disruptions by relocating to favourable habitats, and dramatic range shifts of mobile marine species are among the conspicuous impacts of MHWs1,4,12,13. Whereas spatial temperature shifts have been studied extensively in the context of long-term warming trends14-18, they are unaccounted for in existing global MHW analyses. Here we introduce thermal displacement as a metric that characterizes MHWs by the spatial shifts of surface temperature contours, instead of by local temperature anomalies, and use an observation-based global sea surface temperature dataset to calculate thermal displacements for all MHWs from 1982 to 2019. We show that thermal displacements during MHWs vary from tens to thousands of kilometres across the world's oceans and do not correlate spatially with MHW intensity. Furthermore, short-term thermal displacements during MHWs are of comparable magnitude to century-scale shifts inferred from warming trends18, although their global spatial patterns are very different. These results expand our understanding of MHWs and their potential impacts on marine species, revealing which regions are most susceptible to thermal displacement, and how such shifts may change under projected ocean warming. The findings also highlight the need for marine resource management to account for MHW-driven spatial shifts, which are of comparable scale to those associated with long-term climate change and are already happening.


Assuntos
Migração Animal , Organismos Aquáticos , Ecossistema , Calor Extremo , Aquecimento Global , Água do Mar/análise , Animais , Calor Extremo/efeitos adversos , Aquecimento Global/estatística & dados numéricos , História do Século XX , História do Século XXI , Modelos Teóricos , Oceanos e Mares
14.
Mar Pollut Bull ; 159: 111505, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32768674

RESUMO

This paper analyzed the spatiotemporal distribution of heavy metals in 6746 samples of aquatic organisms (fishes, shrimp and crabs), to make health risk assessments of six heavy metals (As, Cd, Cr, Cu, Hg and Pb). The results indicated that there were significant differences of heavy metal concentrations between different groups of aquatic organisms, months and provinces. The concentrations of Cd, Cr, Hg and Pb varied greatly within one year, with levels higher in summer and autumn, and lower in spring and winter. Crabs in Shandong, Shanxi, Zhejiang and Shanghai posed a high risk of Cd exposure, with the average Cd level exceeding the limit set by China (0.5 mg/kg, w.w.). In addition, the average TRCd value in sea crab was greater than 10-4, indicating a high cancer risk. However, the average THQ values of the six metals were all below 1 in China, and there was no overall non-carcinogenic risk.


Assuntos
Braquiúros , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos , China , Monitoramento Ambiental , Peixes , Medição de Risco
15.
Proc Biol Sci ; 287(1933): 20200889, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811304

RESUMO

Overexploitation is recognized as one of the main threats to global biodiversity. Here, we report a widespread change in the functional diversity of fisheries catches from the large marine ecosystems (LMEs) of the world over the past 65 years (1950 to 2014). The spatial and temporal trends of functional diversity exploited from the LMEs were calculated using global reconstructed marine fisheries catch data provided by the Sea Around Us initiative (including subsistence, artisanal, recreational, industrial fisheries, and discards) and functional trait data available in FishBase. Our analyses uncovered a substantial increase in the functional richness of both ray-finned fishes (80% of LMEs) and cartilaginous species (sharks and rays) (75% of LMESs), in line with an increase in the taxonomic richness, extracted from these ecosystems. The functional evenness and functional divergence of these catches have also altered substantially over the time span of this study, with considerable geographic variation in the patterns detected. These trends show that global fisheries are increasingly targeting species that play diverse roles within the marine ecosystem and underline the importance of incorporating functional diversity in ecosystem management.


Assuntos
Biodiversidade , Pesqueiros/estatística & dados numéricos , Animais , Organismos Aquáticos , Biomassa , Conservação dos Recursos Naturais , Ecossistema , Peixes , Tubarões
16.
Toxicon ; 186: 151-159, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32798503

RESUMO

Heavy metals and microcystins commonly co-exist in water bodies with cyanobacteria, and have been shown to affect aquatic plants. However, their combined effects remain largely unknown. In this study, the toxic effects of copper (Cu) and cadmium (Cd) on Ceratophyllum demersum L. were characterized in the presence of microcystin-LR (MC-LR). The results showed that the bioaccumulation of MC-LR and Cu/Cd in C. demersum was significantly increased by the interaction between MC-LR and Cu/Cd. The combined toxicity assessment results suggested that the toxicities of Cu or Cd to C. demersum would be largely exacerbated by MC-LR, which could be the results of increased bioaccumulation of the pollutants. Cu, Cd and MC-LR, as well as their mixture, significantly decreased plant fresh weight and total chlorophyll content of C. demersum, especially at their high concentrations. The antioxidative system was activated to cope with the adverse effects of oxidative stress. Antioxidant enzyme activities were significantly stimulated by Cu, Cd and MC-LR, as well as their mixture. However, the decreased superoxide dismutase (SOD) and glutathione reductase (GR) activities were observed when exposed to relative high concentrations of Cu or Cd together with MC-LR of 5 µg L-1. MC-LR brought more stress to the antioxidative system, which is another possible explanation for the synergistic effect. Our findings highlight increased ecological risks of the co-contamination of heavy metals and harmful cyanobacteria.


Assuntos
Cádmio/toxicidade , Cobre/toxicidade , Microcistinas/toxicidade , Traqueófitas/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Traqueófitas/fisiologia
17.
Environ Pollut ; 266(Pt 2): 115269, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32836046

RESUMO

ß-blockers are a class of medications widely used to treat cardiovascular disorders, including abnormal heart rhythms, high blood pressure, and angina pectoris. The prevalence of ß-blockers has generated a widespread concern on their potential chronic toxicity on aquatic organisms, highlighting the necessity of comprehensive studies on their environmental distribution, fate, and toxicity. This review summarizes the up-to-date knowledge on the source, global distribution, analytical methods, transformation, and toxicity of ß-blockers. Twelve ß-blockers have been detected in various environmental matrices, displaying significant temporal and spatial variations. ß-blockers can be reduced by 0-99% at wastewater treatment plants, where secondary processes contribute to the majority of removal. Advanced oxidation processes, e.g., photocatalysis and combined UV/persulfate can transform ß-blockers more rapidly and completely than conventional wastewater treatment processes, but the transformation products could be more toxic than the parent compounds. Propranolol, especially its (S)-enantiomer, exhibits the highest toxicity among all ß-blockers. Future research towards improved detection methods, more efficient and cost-effective removal techniques, and more accurate toxicity assessment is needed to prioritize ß-blockers for environmental monitoring and control worldwide.


Assuntos
Poluentes Químicos da Água/análise , Antagonistas Adrenérgicos beta/análise , Organismos Aquáticos , Monitoramento Ambiental , Águas Residuárias
18.
J Environ Radioact ; 222: 106360, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32791373

RESUMO

A radiological box model of the Aegean Sea has been developed simulating the dispersion and fate of radionuclides in the marine environment. The model incorporates all transfer processes within abiotic and biotic compartments in combination with appropriate site-specific information. The model was calibrated using empirical radiological data, with the simulation of 137Cs dispersion after the Chernobyl. Environmental sensitivity analysis has been carried out based on Chernobyl 137Cs fallout, in terms of doses to representative marine organisms (fish, crustacean and molluscs) and human population. Comparison of the results with doses from natural sources and sensitivity estimations for shallow marine environments has been performed in order to reveal the vulnerability of each sub-region. The main characteristics and parameters controlling the radioecological processes are also discussed.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos da Água , Animais , Organismos Aquáticos , Radioisótopos de Césio , Peixes , Humanos , Alimentos Marinhos
19.
Ecotoxicol Environ Saf ; 203: 110992, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32771767

RESUMO

In 2011, the U.S. EPA Office of Research and Development released a field-based method for deriving aquatic life benchmarks for conductivity. Since its release, it has been verified, validated, and corroborated by the authors, reviewers, and independent researchers. However, the method and published results have been recently challenged as being artifacts of small sample sizes, prompting this re-evaluation. This paper supplements prior causal analyses by weighing evidence that specifically addresses the hypothesis that the benchmark is a statistical artifact. Four types of evidence are presented: (1) Permutation analyses show that the data sets are able to reliably estimate the extirpation of 5% of genera. (2) Analyses show that 25 occurrences of a genus are sufficient to estimate extirpation. (3) Coherent ecological explanations show that the claimed influence of sample size is actually a result of community ecology. (4) A review of relevant independent studies supports the benchmark. The permutation test is a useful test of the adequacy of field data sets. Furthermore, this weight-of-evidence approach and the individual types of evidence can be a model for analysis of other field-based benchmark values.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Monitoramento Ambiental/métodos , Benchmarking , Tamanho da Amostra , West Virginia
20.
Ecotoxicol Environ Saf ; 202: 110955, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800229

RESUMO

The effects of cadmium (Cd) have been investigated in an aquatic plant Ottelia alismoides grown under low CO2. Under low CO2, no Cd treated O. alismoides operated three carbon dioxide-concentrating mechanisms (CCMs) efficiently, including HCO3- acquisition, C4 and CAM photosynthesis. After 4 days of treatment with 200 µM and 2000 µM Cd, O. alismoides exhibited an elevated Cd accumulation along with the increasing Cd concentration. Both Cd treatments induced appreciable phytotoxicities in O. alismoides. The leaves showed chlorosis symptoms and the anatomy as well as chloroplast ultrastructure were obviously damaged. Significant decreases in the content of pigments, chlorophyll fluorescence (Fv/Fm and Yield of PS II) and carbon isotope ratio (δ13C) were measured in leaf extracts of O. alismoides grown with both concentrations of Cd. In addition, the pH-drift technique showed that both Cd-treated O. alismoides plants could not uptake HCO3-. The maximum and minimum acidity in Cd-exposed O. alismoides were greatly decreased and the diurnal change of acidity was absent in both Cd treated plants. Furthermore, significant decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), pyruvate phosphate dikinase (PPDK) and phosphoenolpyruvate carboxylase (PEPC) activities were also found at Cd treated O. alismoides plants, indicating the disturbance within C4 cycle. The alterations in the functionality of CCMs in O. alismoides induced by Cd might be related with the inhibition of the enzymes such as carbonic anhydrase (CA) and PEPC involved in inorganic carbon fixation, and the destruction of chloroplasts, as well as the re-allocation of energy and nutrients involved in CCMs and Cd detoxification.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cádmio/toxicidade , Dióxido de Carbono/metabolismo , Hydrocharitaceae/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Organismos Aquáticos/metabolismo , Anidrases Carbônicas/metabolismo , Cloroplastos/metabolismo , Hydrocharitaceae/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA