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1.
Ecotoxicol Environ Saf ; 208: 111665, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396175

RESUMO

Microplastics are ubiquitous in aquatic ecosystems, but little information is currently available on the dangers and risks to living organisms. In order to assess the ecotoxicity of environmental microplastics (MPs), samples were collected from the beaches of two islands in the Guadeloupe archipelago, Petit-Bourg (PB) located on the main island of Guadeloupe and Marie-Galante (MG) on the second island of the archipelago. These samples have a similar polymer composition with mainly polyethylene (PE) and polypropylene (PP). However, these two samples are very dissimilar with regard to their contamination profile and their toxicity. MPs from MG contain more lead, cadmium and organochlorine compounds while those from PB have higher levels of copper, zinc and hydrocarbons. The leachates of these two samples of MPs induced sublethal effects on the growth of sea urchins and on the pulsation frequency of jellyfish ephyrae but not on the development of zebrafish embryos. The toxic effects are much more marked for samples from the PB site than those from the MG site. This work demonstrates that MPs can contain high levels of potentially bioavailable toxic substances that may represent a significant ecotoxicological risk, particularly for the early life stages of aquatic animals.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Ecossistema , Ecotoxicologia , Ilhas , Microplásticos/química , Cifozoários/efeitos dos fármacos , Cifozoários/crescimento & desenvolvimento , Ouriços-do-Mar/efeitos dos fármacos , Ouriços-do-Mar/crescimento & desenvolvimento , Poluentes Químicos da Água/química
2.
Aquat Toxicol ; 230: 105694, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33316747

RESUMO

Psychotropics, especially benzodiazepines, are commonly prescribed worldwide. Poorly eliminated at wastewater treatment plants, they belong to a group of emerging contaminants. Due to their interaction with the GABAA receptor, they may affect the function of the nervous system of non-target organisms, such as aquatic organisms. The toxicity of oxazepam, a very frequently detected benzodiazepine in continental freshwater, has been largely studied in aquatic vertebrates over the last decade. However, its effects on freshwater non-vertebrates have received much less attention. We aimed to evaluate the long-term effects of oxazepam on the juvenile stage of a freshwater gastropod widespread in Europe, Radix balthica. Juveniles were exposed for a month to environmentally-relevant concentrations of oxazepam found in rivers (0.8 µg/L) and effluents (10 µg/L). Three main physiological functions were studied: feeding, growth, and locomotion. Additionally, gene expression analysis was performed to provide insights into toxicity mechanisms. There was a strong short-term activation of the feeding rate at low concentration, whereas the high dose resulted in long-term inhibition of food intake. A significant decrease in mortality rate was observed in juveniles exposed to the lowest dose. Shell growth and locomotor activity did not appear to be affected by oxazepam. Transcriptomic analysis revealed global over-expression of genes involved in the nervous regulation of the feeding, digestive, and locomotion systems after oxazepam exposure. The molecular analysis also revealed a possible interference of animal manipulation with the molecular effects induced by oxazepam exposure. Overall, these results improve our understanding of the effects of the psychoactive drug oxazepam on an aquatic mollusc gastropod.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Gastrópodes/efeitos dos fármacos , Oxazepam/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Gastrópodes/genética , Gastrópodes/crescimento & desenvolvimento , Atividade Motora/efeitos dos fármacos , Oxazepam/análise , Rios/química , Poluentes Químicos da Água/análise
3.
Aquat Toxicol ; 228: 105650, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33035767

RESUMO

Micro(nano)plastics (MPs/NPs) are already present as contaminants in the natural environment globally and have been shown to be difficult to degrade, resulting in the potential for ecological damage and public health concerns. However, the adverse effects of exposure to MPs/NPs by aquatic organisms, especially freshwater microalgae, remains unclear. In the present study, the growth, physiology and transcriptome of the freshwater microalgae Euglena gracilis were comprehensively analyzed following exposure to 1 mg/L of polystyrene (PS) microbeads (5 µm PS-MPs and 100 nm PS-NPs), 0.5 mg/L cadmium (Cd), or a mixture of PS microbeads and Cd for 96 h. Results showed that the toxicity of PS-MPs to microalgae was greater than PS-NPs, inducing increased growth inhibition, oxidative damage and decreased photosynthesis pigment concentrations. PS-MPs alone or in combination with Cd caused cavitation within microalgal cells, as well as increasing the number and volume of vacuoles. The combined exposure toxicity test showed that a combination of Cd + PS-NPs was more toxic than Cd + PS-MPs, which may be explained by the transcriptomic analysis results. Differentially expressed genes (DEGs) in the Cd + PS-NPs group were mainly enriched in metabolism-related pathways, suggesting that algal metabolism was hindered, resulting in aggravation of toxicity. The reduced toxicity induced by Cd + PS-MPs may indicate a response to resist external stress processes. In addition, no adsorption of 0.5 mg/L Cd to 1 mg/L PS microbeads was observed, suggesting that adsorption of MPs/NPs and Cd was not the key factor determining the combined toxicity effects in this study.


Assuntos
Cádmio/toxicidade , Exposição Ambiental , Euglena gracilis/genética , Euglena gracilis/fisiologia , Microalgas/genética , Microesferas , Poliestirenos/toxicidade , Transcrição Genética/efeitos dos fármacos , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Euglena gracilis/efeitos dos fármacos , Euglena gracilis/ultraestrutura , Perfilação da Expressão Gênica , Ontologia Genética , Microalgas/efeitos dos fármacos , Microalgas/fisiologia , Microalgas/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Pigmentos Biológicos/metabolismo , Poluentes Químicos da Água/toxicidade
4.
Bull Environ Contam Toxicol ; 105(5): 777-783, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33044567

RESUMO

The capacity of Lemna minor to remediate toxic heavy metals from wastewater is reasonably well documented. In view of the pivotal role of this species in the environmental clean-up, here we evaluated the bioaccumulation potential of L. minor for cadmium (Cd), lead (Pb), and nickel (Ni) through a controlled experiment. L. minor tolerated the metals Cd, Ni, and Pb up to 0.5, 5, and 8 mg/L, respectively, and beyond these concentrations the toxicity symptoms appeared. Bio-concentration factor varied at different concentrations of heavy metals tested. Overall, L. minor showed good phytoremediation potential for all the three tested heavy metals (Cd, Ni, and Pb), though in relative terms it was more effective in extracting Ni and Cd, as compared to Pb, both in single and mixed concentrations. In view of the growing pollution in Kashmir Himalayan aquatic habitats the phytoremediation by invasive species such as L. minor promises to be one of the best choices than other native plants for cleaning up of polluted soils/water because of its fast growth rate, high abundance, easy handling, and wide distribution in Kashmir Himalayan aquatic ecosystems.


Assuntos
Organismos Aquáticos/metabolismo , Araceae/metabolismo , Bioacumulação , Metais Pesados/metabolismo , Águas Residuárias/química , Organismos Aquáticos/crescimento & desenvolvimento , Araceae/crescimento & desenvolvimento , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Ecossistema , Índia , Lagos , Chumbo/análise , Chumbo/metabolismo , Metais Pesados/análise , Níquel/análise , Níquel/metabolismo
5.
Nature ; 585(7826): 557-562, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32939093

RESUMO

Climate and physiology shape biogeography, yet the range limits of species can rarely be ascribed to the quantitative traits of organisms1-3. Here we evaluate whether the geographical range boundaries of species coincide with ecophysiological limits to acquisition of aerobic energy4 for a global cross-section of the biodiversity of marine animals. We observe a tight correlation between the metabolic rate and the efficacy of oxygen supply, and between the temperature sensitivities of these traits, which suggests that marine animals are under strong selection for the tolerance of low O2 (hypoxia)5. The breadth of the resulting physiological tolerances of marine animals predicts a variety of geographical niches-from the tropics to high latitudes and from shallow to deep water-which better align with species distributions than do models based on either temperature or oxygen alone. For all studied species, thermal and hypoxic limits are substantially reduced by the energetic demands of ecological activity, a trait that varies similarly among marine and terrestrial taxa. Active temperature-dependent hypoxia thus links the biogeography of diverse marine species to fundamental energetic requirements that are shared across the animal kingdom.


Assuntos
Organismos Aquáticos/classificação , Organismos Aquáticos/metabolismo , Ecossistema , Filogeografia , Aerobiose , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Metabolismo Basal , Aves/metabolismo , Peso Corporal , Hipóxia/metabolismo , Hipóxia/veterinária , Mamíferos/metabolismo , Oxigênio/metabolismo , Répteis/metabolismo , Especificidade da Espécie , Temperatura
6.
PLoS One ; 15(9): e0239842, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986752

RESUMO

Quantitative assessments of the capacity of marine reserves to restore historical fish body-size distributions require extensive repeated sampling to map the phenotypic responses of target populations to protection. However, the "no take" status of marine reserves oftentimes precludes repeated sampling within their borders and, as a result, our current understanding of the capacity of marine reserves to restore historical body-size distributions remains almost entirely reliant on independent, static visual surveys. To overcome this challenge, we promote the application of a traditional fisheries tool known as a "back-calculation", which allows for the estimation of fish body lengths from otolith annuli distances. This practical application was pursued in this study, using data collected in five marine reserves and adjacent fished reefs in the Philippines, to investigate spatiotemporal disparities in length-at-age of the brown surgeonfish, Acanthurus nigrofuscus. The spatial component of our analyses revealed that 1) A. nigrofuscus were phenotypically similar between marine reserves and fished reefs during their early life history; 2) marine reserve and fished reef populations diverged into significantly different length-at-age morphs between ages three and six, in which protected fish were predominantly larger than conspecifics in fished reefs; and 3) A. nigrofuscus returned to a state of general phenotypic similarity during later life. The temporal component of our analyses revealed that younger generations of A. nigrofuscus exhibited significant, positive year effects that were maintained until age eight, indicating that, within the significant age cohorts, younger generations were significantly larger than older generations.


Assuntos
Envelhecimento/fisiologia , Organismos Aquáticos/crescimento & desenvolvimento , Tamanho Corporal , Recifes de Corais , Percas/crescimento & desenvolvimento , Fatores Etários , Análise de Variância , Animais , Conservação dos Recursos Naturais , Pesqueiros , Fenótipo , Filipinas
7.
PLoS One ; 15(9): e0238405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936809

RESUMO

In the California Current Ecosystem, El Niño acts as a natural phenomenon that is partially representative of climate change impacts on marine bacteria at timescales relevant to microbial communities. Between 2014-2016, the North Pacific warm anomaly (a.k.a., the "blob") and an El Niño event resulted in prolonged ocean warming in the Southern California Bight (SCB). To determine whether this "marine heatwave" resulted in shifts in microbial populations, we sequenced the rpoC1 gene from the biogeochemically important picocyanobacteria Prochlorococcus and Synechococcus at 434 time points from 2009-2018 in the MICRO time series at Newport Beach, CA. Across the time series, we observed an increase in the abundance of Prochlorococcus relative to Synechococcus as well as elevated frequencies of ecotypes commonly associated with low-nutrient and high-temperature conditions. The relationships between environmental and ecotype trends appeared to operate on differing temporal scales. In contrast to ecotype trends, most microdiverse populations were static and possibly reflect local habitat conditions. The only exceptions were microdiversity from Prochlorococcous HLI and Synechococcus Clade II that shifted in response to the 2015 El Niño event. Overall, Prochlorococcus and Synechococcus populations did not return to their pre-heatwave composition by the end of this study. This research demonstrates that extended warming in the SCB can result in persistent changes in key microbial populations.


Assuntos
El Niño Oscilação Sul , Prochlorococcus/isolamento & purificação , Água do Mar/microbiologia , Synechococcus/isolamento & purificação , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Organismos Aquáticos/isolamento & purificação , Biodiversidade , California , Mudança Climática , Ecossistema , Ecótipo , Genes Bacterianos , Microbiota/genética , Oceano Pacífico , Filogenia , Prochlorococcus/genética , Prochlorococcus/crescimento & desenvolvimento , Estações do Ano , Synechococcus/genética , Synechococcus/crescimento & desenvolvimento , Temperatura
8.
Ecotoxicol Environ Saf ; 203: 111024, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32741747

RESUMO

Pontederia cordata can tolerate heavy metal toxicity and possesses great potential for phytoremediation of heavy-metal-contaminated wetlands, yet how it copes with heavy metal stress has still not been determined. Hydroponic experiments were used to assess the effects of various levels of Cd2+ on the photosynthesis and activity of redox-regulatory systems in the plant leaves, and we also sought to elucidate the tolerance mechanism of the plant to Cd2+ by investigating Cd2+ enrichment characteristics and chemical forms. The plant can manage a low cadmium concentration (≤0.04 mM) with relatively stable biomass and photosynthetic performance. Cd2+ at the highest concentration (0.44 mM) decreased superoxide dismutase and peroxidase activities by 37.17% and 93.29%, respectively. Similar trends were demonstrated in the contents of ascorbic acid, carotenoids, lutein, glutathione, and non-protein thiol, as well as phytochelation in the leaves, exacerbating membrane peroxidation despite the significantly increased catalase activity observed. Moreover, the highest Cd2+ concentration disturbed the biosynthesis of chlorophyll precursors in the leaves, reduced chlorophyll a and b, as well as total chlorophyll contents by 60.47%, 67.47%, and 68.12%, respectively, which inhibited photosynthesis, leading to a decline in biomass. Compared with maximum quantum efficiency (Fv/Fm) and the potential activity (Fv/Fo) of photosystem II, the performance index for energy conservation from photons absorbed by PSII to the reduction of intersystem electron acceptors (PIabs), and of PSI end acceptors (PItotal), can indicate Cd2+ toxicity to the photosynthetic apparatus in the leaves. 49.95%-76.90% of the Cd2+ was sequestered in the plant roots, restraining translocation from roots to shoots, which is considered a tolerance mechanism, probably resulting from disturbed transpiration in leaves and increased Cd2+ content with low activity. Pontederia cordata is a candidate plant for phytoremediation of heavy-metal -contaminated wetlands.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Cádmio/toxicidade , Pontederiaceae/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Áreas Alagadas , Organismos Aquáticos/metabolismo , Ácido Ascórbico/farmacologia , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Carotenoides/metabolismo , Clorofila A/metabolismo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Pontederiaceae/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/metabolismo
9.
PLoS One ; 15(6): e0235167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603344

RESUMO

The 2010 Deepwater Horizon blowout off the coast of Louisiana caused the largest marine oil spill on record. Samples were collected 2-3 months after the Macondo well was capped to assess damage to macrofauna and meiofauna communities. An earlier analysis of 58 stations demonstrated severe and moderate damage to an area of 148 km2. An additional 58 archived stations have been analyzed to enhance the resolution of that assessment and determine if impacts occurred further afield. Impacts included high levels of total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) in the sediment, low diversity, low evenness, and low taxonomic richness of the infauna communities. High nematode to copepod ratios corroborated the severe disturbance of meiofauna communities. Additionally, barium levels near the wellhead were very high because of drilling activities prior to the accident. A principal component analysis (PCA) was used to summarize oil spill impacts at stations near the Macondo well, and the benthic footprint of the DWH oil spill was estimated using Empirical Bayesian Kriging (EBK) interpolation. An area of approximately 263 km2 around the wellhead was affected, which is 78% higher than the original estimate. Particularly severe damages to benthic communities were found in an area of 58 km2, which is 142% higher than the original estimate. The addition of the new stations extended the area of the benthic footprint map to about twice as large as originally thought and improved the resolution of the spatial interpolation. In the future, increasing the spatial extent of sampling should be a top priority for designing assessment studies.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Biodiversidade , Sedimentos Geológicos/química , Poluição por Petróleo/análise , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Golfo do México , Louisiana , Análise de Componente Principal , Análise Espacial
10.
Biofouling ; 36(2): 138-145, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32223324

RESUMO

New processing routes and materials for non-biocidal, antifouling (AF) coatings with an improved performance are currently much sought after for a range of marine applications. Here, the processing, physical properties and marine AF performance of a fluorinated coating based on a thermoplastic (non-crosslinked) fluorinated polymer are reported. It was found that the addition of lubricating oil and hydrodynamic drag reducing microstructures improved the AF properties substantially, i.e. the settlement of a marine biofilm, containing mixed microalgae including diatoms, was reduced to low levels. More importantly, the remaining fouling was removed from the coatings at low hydrodynamic shear rates and promising AF properties were obtained. Moreover, additional potential benefits were revealed originating from the thermoplastic nature of the coating material which might result in significant cost reductions.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Incrustação Biológica/prevenção & controle , Polímeros de Fluorcarboneto/química , Borracha/química , Diatomáceas/crescimento & desenvolvimento , Hidrodinâmica , Microalgas/crescimento & desenvolvimento , Propriedades de Superfície
11.
Biofouling ; 36(2): 169-182, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32233656

RESUMO

This paper describes the design of an enhanced, plane channel, flowcell and its use for testing large-scale coated plates (0.6 m × 0.22 m) in fully developed flow, over a wide range of Reynolds numbers, with low uncertainty. Two identical, hydraulically smooth plates were experimentally tested. Uniform biofilms were grown on clean surfaces to test skin friction changes resulting from different biofilm thickness and densities. A velocity survey of the flowcell measurement section, using laser Doppler anemometry, showed a consistent velocity profile and low turbulence intensity in the central flow channel. The skin friction coefficient was experimentally determined using a pressure drop method. Results correlate closely to previously published regression data, particularly at higher speeds. Repeated measurements indicated very low uncertainty. This study demonstrates this flowcell's applicability for representing consistent frictional drag of ship hull surfaces, enabling comparability of hydrodynamic drag caused by surface roughness to the reference surface measurements.


Assuntos
Biofilmes/crescimento & desenvolvimento , Incrustação Biológica/prevenção & controle , Teste de Materiais/métodos , Aço Inoxidável/química , Organismos Aquáticos/crescimento & desenvolvimento , Fricção , Hidrodinâmica , Navios , Estresse Mecânico , Propriedades de Superfície
12.
Ecotoxicol Environ Saf ; 194: 110400, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32135379

RESUMO

The effects of increasing temperature owing to thermal discharge and global warming on zooplanktons such as Daphnia magna are a growing concern. The purpose of this study was to evaluate the effects of elevated temperature (25 °C) on oxidative stress responses, growth, and reproduction of D. magna across 10 generations. The number of offspring per female at 21 d was significantly increased and the rate of adult somatic growth (5-21 d) was decreased in the F0 generation at 25 °C compared with those at the reference temperature 20 °C. However, the F3 generation showed the lowest number of offspring and the highest adult somatic growth rate and oxidative stress responses (5 d) at 25 °C. Moreover, all life-history traits seemed to recover to the levels of the control group from the F6 generation at 20 °C. These findings suggest that D. magna under continuous thermal stress exhibits non-adaptive responses in the early generations (F0-F3) and changes to adaptive responses in the later generations (F6-F9). However, the underlying epigenetic mechanism should be identified in the future.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Daphnia/crescimento & desenvolvimento , Resposta ao Choque Térmico , Estresse Oxidativo , Animais , Organismos Aquáticos/fisiologia , Daphnia/fisiologia , Feminino , Resposta ao Choque Térmico/fisiologia , Modelos Teóricos , Estresse Oxidativo/fisiologia , Reprodução/fisiologia , Temperatura , Água/química
13.
Aquat Toxicol ; 221: 105425, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32058875

RESUMO

Neurotoxin ß-N-methylamino-L-alanine (BMAA) has been widely detected in diverse aquatic organisms and hypothesized as an environmental risk to neurodegenerative diseases in humans. However, the knowledge of its toxicity to marine organisms requires attention. In the present study, embryos and sperm of the sea urchin, Lytechinus pictus, were used to assess the toxicity of BMAA. Effects of BMAA on fertilization and development of sea urchin embryos were measured, and its impacts on efflux transport of sea urchin blastula were also assayed. Results demonstrated that the fertilization and development of embryos were significantly inhibited by high concentrations of BMAA above 300 µg L-1. The EC50 values indicated by active swimming larvae and total larvae numbers at 96 HPF (hours post fertilization) were 165 µg L-1 (1.4 µmol L-1) and 329 µg L-1 (2.8 µmol L-1), respectively. Additionally, sperm exposed to BMAA for 10 min significantly reduced the fertilization ratio of sea urchin eggs. However, the ABC transport activity on the cytomembrane of sea urchin blastula was not inhibited by the presence of BMAA at 50 µg L-1, even up to 500 µg L-1. Abnormal division and developmental malformations occurred at different developmental stages for sea urchin embryos exposed to BMAA at 500 µg L-1. The inhibitory effects of BMAA on sea urchin embryos were reported at the first time in this study, for which the toxicological mechanisms will be explored in future studies.


Assuntos
Diamino Aminoácidos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Fertilização/efeitos dos fármacos , Lytechinus/efeitos dos fármacos , Neurotoxinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Lytechinus/crescimento & desenvolvimento , Masculino , Espermatozoides/efeitos dos fármacos
14.
PLoS One ; 15(2): e0229453, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084252

RESUMO

The Atacama Desert (21-26°S) is currently one of the driest places on Earth and metal(loid)s are of special concern for this region, which hosts the largest-known porphyry copper deposits produced in Chile. Evidence of past environmental conditions is commonly preserved in natural archives, such as lacustrine sediments. Sediment records obtained from Inca Coya Lake (22°20'S-68°35'W, 2534 m.a.s.l.), a small lake located in the Atacama Desert, reflected the evolution of regional mining activity during the 20th century and sedimentation associated with decadal climate variability. We studied the aquatic community structure changes recorded in sediment records from Inca Coya Lake. By analysis of magnetic properties (susceptibility, hysteresis curves and Curie temperatures), grain size and geochemical composition of the sediments, we identified environmental periods and changes in the community of benthic and planktonic organisms (diatoms and diapausing egg bank). We identified three detrital episodes that we interpret as dry/wet phases during the last 90 years associated with the increase of flash flood events promoting hypoxia oscillations; anthropogenic (mining activity) signals were also identified. Invertebrate community structure (primary consumers) reflected the metal exposure, measured as changes in assemblage composition through species turnover. Diatom community composition was best associated with variables related to wetter/drier alternation and consequent changes in oxygen availability. Bioindicators analyzed (diatoms, diapausing egg bank and invertebrate community) demonstrated to be excellent indicators of the bioavailability of compounds in the aquatic ecosystem of Inca Coya Lake, allowing the environmental impact assessment of the water resources due to flash floods and mining activity in the driest desert of the world.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Ecossistema , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Lagos/análise , Metais/análise , Animais , Organismos Aquáticos/metabolismo , Chile , Clima Desértico , Magnetismo
15.
Int J Mol Sci ; 21(3)2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31979128

RESUMO

Marine biofilms are composed of many species of bacteria, unicellular algae, and protozoa. Biofilms can induce, inhibit, or have no effect on settlement of larvae and spores of algae. In this review, we focus on induction of larval settlement by marine bacteria and unicellular eukaryotes and review publications from 2010 to September 2019. This review provides insights from meta-analysis on what is known about the effect of marine biofilms on larval settlement. Of great interest is the impact of different components of marine biofilms, such as bacteria and diatoms, extracellular polymeric substances, quorum sensing signals, unique inductive compounds, exoenzymes, and structural protein degradation products on larval settlement and metamorphosis. Molecular aspects of larval settlement and impact of climate change are reviewed and, finally, potential areas of future investigations are provided.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Animais , Bactérias/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Humanos , Metamorfose Biológica/fisiologia
16.
Appl Microbiol Biotechnol ; 104(2): 515-525, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31807887

RESUMO

Marine is the harshest corrosive environment where almost all marine underwater equipment and facilities undergo corrosion caused by marine microorganisms. With the development of marine resources globally, the marine engineering and relevant infrastructures have increased exponentially. Microbiologically influenced corrosion (MIC) leads to severe safety accidents and great economic losses. The specific aggregation of corrosive microbial communities and their interactions with materials conform to a typical ecological adaptation mechanism. On the one hand, corrosive biofilms in the marine environment selectively colonize on a specific steel substrate by utilizing their complex community composition and various extracellular polymeric substances; on the other hand, the elemental composition and surface microstructure of different engineering steels affect the microbial community and corrosive process. MIC in the marine environment is a dynamic process evolving with the formation of corrosive biofilms and corrosion products. In this mini-review, the interactions between corrosive biofilm and steel substrates are explored and discussed, especially those conducted in situ in the marine environment. Herein, the important role of iron in the dynamic process of marine corrosion is highlighted.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Organismos Aquáticos/metabolismo , Biofilmes/crescimento & desenvolvimento , Corrosão , Ferro/metabolismo , Microbiota , Aço
17.
Aquat Toxicol ; 218: 105355, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31790937

RESUMO

The growing popularity of physical sunscreens will lead to an increased release of ingredients from zinc oxide (ZnO) sunscreens into marine environments. Though zinc (Zn) is a necessary micronutrient in the ocean, greater than natural Zn concentrations may be released into marine environments by use of sunscreens. The extent of the consequences of this addition of Zn to the ocean are not fully understood. We investigated the effects of materials released by ZnO- sunscreens on the development of California purple sea urchin, Strongylocentrotus purpuratus. Embryos incubated in various concentrations of Zn (0.01, 0.05, 0.1, 0.5, and 1 mg/L), the sources of which included zinc-containing compounds: ZnO and zinc sulfate (ZnSO4); and ZnO sunscreens: All Good, Badger, and Raw Elements brands. Based on EC50 values, ZnO-containing sunscreens were slightly, but not significantly, more toxic than ZnO and ZnSO4, suggesting that sunscreens may release additional unknown materials that are detrimental to sea urchin embryo development. All concentrations of Zn-exposure resulted in significant malformations (skeletal abnormality, stage arrest, axis determination disruption), which were identified using light and fluorescence confocal microscopy. The concentration of Zn2+ internalized by the developing embryos correlated positively with the concentration of Zn in seawater. Additionally, exposure to both ZnO sunscreens and ZnO and ZnSO4 at 1 mg/L Zn, significantly increased calcein-AM (CAM) accumulation, indicating decreased multidrug resistant (MDR) transporter activity. This is one of the first studies documenting ZnO-containing sunscreens release high concentrations of Zn that are internalized by and have detrimental effects on aquatic organisms.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Strongylocentrotus purpuratus/efeitos dos fármacos , Protetores Solares/uso terapêutico , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Sulfato de Zinco/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Fluoresceínas/metabolismo , Água do Mar/química , Strongylocentrotus purpuratus/embriologia
18.
Ecotoxicol Environ Saf ; 188: 109881, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704324

RESUMO

N,N-diethyl-meta-toluamide (DEET) is the most widely used active ingredient in commercial insect repellents. In addition to its adverse effects in insects, DEET can affect non-target organisms in surface water systems. Nevertheless, the aquatic life criteria of DEET are not available. This study conducted both acute and chronic toxicity tests on DEET in native Chinese aquatic species, and derived its criterion maximum concentration (CMC) and criterion continuous concentration (CCC). The determined CMC and CCC of DEET were 21.53 and 0.52 mg/L, respectively. The toxicity data indicated that DEET exposure posed a higher toxicity to some algae than other aquatic species. Compared with other insect repellents, DEET exposure posed a moderate toxicity to aquatic species. Therefore, the exposure concentration of DEET in Chinese surface water was collected to assess the potential ecological risk. The preliminary ecological risk assessment showed that DEET posed negligible risk to aquatic ecosystems in China. However, considering its toxic effects on the growth and reproduction to aquatic organisms, the ecological risk posed by DEET is worth further concern.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , DEET/toxicidade , Exposição Ambiental/análise , Repelentes de Insetos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/classificação , Organismos Aquáticos/crescimento & desenvolvimento , Organismos Aquáticos/fisiologia , China , DEET/análise , Repelentes de Insetos/análise , Medição de Risco , Especificidade da Espécie , Testes de Toxicidade , Poluentes Químicos da Água/análise
19.
Ann Rev Mar Sci ; 12: 469-497, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31505131

RESUMO

More than two-thirds of global biomass consists of vascular plants. A portion of the detritus they generate is carried into the oceans from land and highly productive blue carbon ecosystems-salt marshes, mangrove forests, and seagrass meadows. This large detrital input receives scant attention in current models of the global carbon cycle, though for blue carbon ecosystems, increasingly well-constrained estimates of biomass, productivity, and carbon fluxes, reviewed in this article, are now available. We show that the fate of this detritus differs markedly from that of strictly marine origin, because the former contains lignocellulose-an energy-rich polymer complex of cellulose, hemicelluloses, and lignin that is resistant to enzymatic breakdown. This complex can be depolymerized for nutritional purposes by specialized marine prokaryotes, fungi, protists, and invertebrates using enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases to release sugar monomers. The lignin component, however, is less readily depolymerized, and detritus therefore becomes lignin enriched, particularly in anoxic sediments, and forms a major carbon sink in blue carbon ecosystems. Eventual lignin breakdown releases a wide variety of small molecules that may contribute significantly to the oceanic pool of recalcitrant dissolved organic carbon. Marine carbon fluxes and sinks dependent on lignocellulosic detritus are important ecosystem services that are vulnerable to human interventions. These services must be considered when protecting blue carbon ecosystems and planning initiatives aimed at mitigating anthropogenic carbon emissions.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Ciclo do Carbono , Monitoramento Ambiental/métodos , Lignina/química , Modelos Teóricos , Plantas/química , Organismos Aquáticos/enzimologia , Biomassa , Sequestro de Carbono , Ecossistema , Oceanos e Mares
20.
Ann Rev Mar Sci ; 12: 499-523, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31451083

RESUMO

In the last few decades, numerous studies have investigated the impacts of simulated ocean acidification on marine species and communities, particularly those inhabiting dynamic coastal systems. Despite these research efforts, there are many gaps in our understanding, particularly with respect to physiological mechanisms that lead to pathologies. In this review, we trace how carbonate system disturbances propagate from the coastal environment into marine invertebrates and highlight mechanistic links between these disturbances and organism function. We also point toward several processes related to basic invertebrate biology that are severely understudied and prevent an accurate understanding of how carbonate system dynamics influence organismic homeostasis and fitness-related traits. We recommend that significant research effort be directed to studying cellular phenotypes of invertebrates acclimated or adapted to elevated seawater pCO2 using biochemical and physiological methods.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Dióxido de Carbono/análise , Carbonatos/toxicidade , Monitoramento Ambiental/métodos , Invertebrados/efeitos dos fármacos , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Carbonatos/análise , Homeostase , Concentração de Íons de Hidrogênio , Invertebrados/crescimento & desenvolvimento , Modelos Teóricos , Poluentes Químicos da Água/análise
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