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1.
Aquat Toxicol ; 217: 105332, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31698182

RESUMO

Calanus hyperboreus is the largest copepod and a key species in the Arctic food web. During the spring bloom, C. hyperboreus builds up large lipid reserves, which enable it to survive and produce eggs during overwintering. The ecological effects of oil exposure on overwintering C. hyperboreus are unknown. The present study empirically tested if exposure to the polycyclic aromatic hydrocarbon (PAH) pyrene from crude oil affects the survival, egg production, and hatching success of overwintering C. hyperboreus. We also tested the delayed effects on faecal pellet production and lipid recovery in clean seawater. Direct exposure did not reduce survival and egg production, but reduced hatching success 3-18 times by the end of the exposure period. Remarkably, we documented strong delayed effects of pyrene on faecal pellet production and the recovery of lipid reserves. The current study reveals a high vulnerability of this key species of Arctic zooplankton to oil exposure during winter. Together with our previous study on C. glacialis, we complete the picture of the impact of oil on the largest and most lipid-rich copepod C. hyperboreus, which potentially can have huge ecological consequences for the fragile Arctic marine food web.


Assuntos
Copépodes/efeitos dos fármacos , Petróleo/efeitos adversos , Pirenos/toxicidade , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Regiões Árticas , Dinamarca , Monitoramento Ambiental , Feminino , Cadeia Alimentar , Petróleo/análise , Poluição por Petróleo/efeitos adversos , Poluição por Petróleo/análise , Pirenos/análise , Reprodução/efeitos dos fármacos , Estações do Ano , Água do Mar/química , Poluentes Químicos da Água/análise
2.
Sci Total Environ ; 692: 1-9, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31326592

RESUMO

Global production of synthetic polymers, led by polyethylene (PE), rose steadily in the last decades, and marine ecosystems are considered as a global sink. Although PE is not biodegradable, in coastal areas it fragments into microplastics (MP) readily taken up by biota, and have been postulated as vectors of hydrophobic chemicals to marine organisms. We have tested this hypothesis using two organisms representative of the marine plankton, the holoplanktonic copepod Acartia clausi, and the meroplanktonic larva of the Paracentrotus lividus sea-urchin, and two model chemicals with similar hydrophobic properties, the 4-n-Nonylphenol and the 4-Methylbenzylidene-camphor used as plastic additive and UV filter in cosmetics. Both test species actively ingested the MP particles. However, the presence of MP never increased the bioaccumulation of neither model chemicals, nor their toxicity to the exposed organisms. Bioaccumulation was a linear function of waterborne chemical disregarding the level of MP. Toxicity, assessed by the threshold (EC10) and median (EC50) effect levels, was either independent of the level of MP or even in some instances significantly decreased in the presence of MPs. These consistent results challenge the assumption that MP act as vectors of hydrophobic chemicals to planktonic marine organisms.


Assuntos
Cânfora/análogos & derivados , Fenóis/toxicidade , Polietileno/análise , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Organismos Aquáticos , Bioacumulação , Cânfora/metabolismo , Cânfora/toxicidade , Copépodes/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Paracentrotus/efeitos dos fármacos , Paracentrotus/crescimento & desenvolvimento , Fenóis/metabolismo , Poluentes Químicos da Água/análise
3.
Chemosphere ; 233: 482-492, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31181495

RESUMO

Rise in cyanobacterial blooms and massive discharge of nanoparticles (NPs) in aquatic ecosystems cause zooplankton to be exposed in toxic food and NPs simultaneously, which may impact on zooplankton interactively. Therefore, the present study focused on assessing the combined effects of different ZnO NPs levels (0, 0.10, 0.15, 0.20 mg L-1) and different proportions of toxic Microcystis (0%, 10%, 20%, 30%) in the food on a model zooplankton, Daphnia magna. The results showed that both toxic Microcystis and ZnO NPs significantly delayed the development of D. magna to maturation, but there was no significant interaction between the two factors on the times to maturation except the body length at maturation. Both ZnO NPs and toxic Microcystis also significantly decreased the number of neonates in the first brood, total offspring, and number of broods per female, and there was a significant interaction between ZnO NPs and food composition on the reproductive performance of D. magna. Specifically, presence of toxic Microcystis reduced the gap among the effects of different ZnO NPs concentrations on the reproductive performance of D. magna. When the ZnO NPs concentration was at 0.15 mg L-1, the gap of the reproductive performance among different proportions of toxic Microcystis also tended to be narrow. Similar phenomenon also occurred in mortality. Such results suggested that low concentration of ZnO NPs and toxic Microcystis can mutually attenuate their harmful effects on D. magna, which has significantly implications in appropriately assessing the ecotoxicological effects of emerging pollutants in a complex food conditions.


Assuntos
Daphnia/efeitos dos fármacos , Microcystis/química , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Animais , Feminino , Cadeia Alimentar , Humanos , Traços de História de Vida , Reprodução/efeitos dos fármacos , Zooplâncton/efeitos dos fármacos , Zooplâncton/crescimento & desenvolvimento
4.
Environ Pollut ; 252(Pt A): 715-722, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31185361

RESUMO

Concerns about possible environmental implications of nano- and micro-plastics are continuously raising. Hence, comprehensive understanding of their behaviour, bioaccumulation and toxicity potential is required. Nevertheless, systematic studies on their fate and possible effects in freshwaters, as well as the influence of particle-specific and environmental factors on their behaviour and impacts are still missing. The aims of the present study are thus two-fold: (i) to examine the role of the surface charge on nanoplastic stability and acute effects to freshwater zooplankton; (ii) to decipher the influence of the refractory natural organic matter (NOM) on the nanoplastic fate and effects. Amidine and carboxyl-stabilized polystyrene (PS) spheres of 200 nm diameter characterized by opposite primary surface charges and neutral buoyancy were selected as model nanoplastics. The results demonstrated that the surface functionalization of the polystyrene nanoplastics controls their aggregation behaviour. Alginate or Suwannee River humic acid (SRHA) modified significantly the surface charge of positively-charged amidine PS nanoplastic and the aggregation state, while had no significant influence on the negatively-charged carboxyl PS nanoplastic. Both amidine and carboxyl PS nanoplastics were ingested by the zooplankton and concentrated mainly in the gut of water flea Daphnia magna and larvae Thamnocephalus platyurus, and the stomach of rotifer Brachionus calyciflorus. Amidine PS nanoplastic was more toxic than carboxyl one. The toxicity decreased in the order D. magna (48 h -immobilization) > B. calyciflorus (24 h - lethality) > T. platyurus (24 h - lethality). Alginate or SRHA reduced significantly the toxicity of both amidine and carboxyl PS nanoplastics to the studied zooplankton representatives. The implications of this laboratory study findings to natural environment were discussed.


Assuntos
Nanopartículas/toxicidade , Plásticos/toxicidade , Poliestirenos/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Anostraca/efeitos dos fármacos , Anostraca/metabolismo , Daphnia/efeitos dos fármacos , Daphnia/metabolismo , Água Doce , Gastrópodes , Substâncias Húmicas , Larva , Rotíferos/efeitos dos fármacos , Rotíferos/metabolismo , Zooplâncton/metabolismo
5.
Chemosphere ; 234: 123-131, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31207418

RESUMO

Microplastics are a ubiquitous contaminant of marine ecosystems that have received considerable global attention. The effects of microplastic ingestion on some marine biota have been evaluated, but the uptake, elimination, and histopathological impacts of microplastics remain under-investigated especially for zooplankton larvae. Here, we show that 10 µm polystyrene microspheres can be ingested and egested by Artemia parthenogenetica larvae, which impact their health. The results indicate that A. parthenogenetica larvae have a varying capacity to consume 10 µm polystyrene microspheres that is dependent on microplastic exposure concentrations, exposure times, and the availability of food. The lowest level of microplastics that was ingested by A. parthenogenetica was 0.15 particles/individual when exposed to 10 particles/mL and 0.05 particles/individual when exposed to 1 particle/mL over 24 h and 14 d, respectively. A. parthenogenetica larvae were able to egest feces with microplastics within 3 h of ingestion. However, ingested microplastics persisted in individuals for up to 14 days. Furthermore, microalgal feeding was significantly reduced by 27.2% in the presence of 102 particles/mL microplastics over 24 h. Histological analyses indicated that a greater abundance of lipid droplets was present among epithelia after 24 h of exposure at a concentration of 10 particles/mL. Moreover, intestinal epithelia were deformed and disorderedly arranged after 14 d of exposure. Overall, these results indicate that marine microplastic pollution could pose a threat to A. parthenogenetica health, especially that of larvae. Consequently, further research is required to evaluate the potential physiological and histopathological effects of microplastics for other marine invertebrate species.


Assuntos
Artemia/metabolismo , Comportamento Alimentar/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Plásticos/farmacocinética , Poliestirenos/farmacocinética , Animais , Artemia/efeitos dos fármacos , Ingestão de Alimentos , Ecossistema , Mucosa Intestinal/patologia , Larva/efeitos dos fármacos , Plásticos/análise , Poliestirenos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética , Zooplâncton/efeitos dos fármacos
6.
Mater Sci Eng C Mater Biol Appl ; 102: 324-340, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147005

RESUMO

Despite the fact that magnetic iron oxide nanoparticles (Fe3O4-MNPs) considered as the most promising nanoparticles (NPs) in biomedicine and environmental biotechnology, their safety and ecotoxicological impacts of biogenic and chemogenic routes of Fe3O4-MNPs in the marine aquatic system is scarcely studied. In this work, we report the optimized and suitable phyco-synthesis route for nano-Fe3O4 based on the six selected species of the Persian Gulf seaweeds: Ulva prolifera, U. flexuosa, U. linza, U. intestinalis, U. clathrata, and Sargassum boveanum. Moreover, antibacterial activities and acute zooplanktonic responses in Artemia salina and acorn barnacle Amphibalanus amphitrite to chemogenic and biogenic Fe3O4-MNPs, were evaluated. Although all the seaweeds extract showed reducing potential for Fe3O4-MNPs green synthesis - mainly on the basis of characterization results- the algal route selectivity has been demonstrated to be important for the biosynthesis of magnetite NPs. Herein, the cubo-spherical and polydisperse U. prolifera-derived Fe3O4-MNPs with particles sizes of 9.59 nm were the best ones. The comparative zooplanktonic cytotoxicity of chemo- and bio-route of Fe3O4-MNPs exhibited no acute toxicity in nauplii and adults of A. salina (96-h EC50 ≥ 1000 mg/L) and the potential of toxicity in A. amphitrite nauplii (48-h EC50 = 466.5 and 842.3 mg/L for chemo- and bio-route of Fe3O4-MNPs, respectively). The in vitro antimicrobial activity of both chemo- and bio-route of magnetite NPs to selective human pathogenic bacteria and fungi (i.e. n = 11) showed strong antagonistic activity against Staphylococcus epidermidis, Bacillus subtilis, B. pumulis, and Saccharomyces cerevisiae. In conclusion, these findings demonstrate the optimized phyco-fabrication of Fe3O4-MNPs as promising nontoxic approach in ecobiotechnology, the new insight about the potential adverse effects of chemosynthesized Fe3O4-MNPs to crustacean zoo-organisms after their possible entrance into the marine environments, and bio/chemo-route Fe3O4-MNPs as pivotal agent for nanoantimicrobials.


Assuntos
Antibacterianos/farmacologia , Nanopartículas de Magnetita/química , Ulva/química , Zooplâncton/efeitos dos fármacos , Adsorção , Animais , Artemia/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Bioensaio , Fungos/efeitos dos fármacos , Nanopartículas de Magnetita/toxicidade , Nanopartículas de Magnetita/ultraestrutura , Magnetometria , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Alga Marinha/química , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termogravimetria , Thoracica/efeitos dos fármacos , Testes de Toxicidade , Difração de Raios X
7.
Ecotoxicology ; 28(6): 643-649, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31197615

RESUMO

Monogonont rotifers constitute, depending on the moment of the year, most of the zooplankton in many freshwater ecosystems. Sexual reproduction is essential in the development cycle of these organisms as it enables them to constitute stocks of cysts which can withstand adverse environmental conditions and hatch when favorable conditions return. However, endocrine disrupting compounds (EDCs) can interfere with the reproduction of organisms. The present work aimed to investigate the effects of cyproterone acetate (CPA, anti-androgen and progestogen synthetic steroid) at 0.5 mg L-1, on the sexual reproduction of Brachionus calyciflorus in a cross-mating experiment. Results show no impact on mixis whereas the fertilization rate and resting egg production were higher in females exposed to CPA (from embryogenesis to adult stage), regardless of the treatment applied to the males with which they were mating (i.e. males hatched from CPA-treated females or from control females). Moreover, neonate females which mothers has been exposed to 0.5 mg L-1 CPA had more oocytes in their germarium than control neonates. Our results suggest that the effects of CPA observed are not related to toxicity but rather are consistent with an endocrine disruption-related impact, probably through disturbance of the mate recognition protein (MRP) production and through interference with a steroid receptor. Moreover, the absence of effect on mixis rate indicates that mixis induction on the one hand and mating process and resting production on the other hand are not controlled by the same hormonal pathways.


Assuntos
Antagonistas de Androgênios/toxicidade , Acetato de Ciproterona/toxicidade , Disruptores Endócrinos/toxicidade , Rotíferos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Reprodução/efeitos dos fármacos , Rotíferos/fisiologia , Zooplâncton/efeitos dos fármacos
8.
Mar Drugs ; 17(5)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035351

RESUMO

Seven previously unreported cyclonerane derivatives, namely, 3,7,11-trihydroxycycloneran-10-one, cycloneran-3,7,10,11-tetraol, cycloneran-3,7,11-triol, 11,12,15-trinorcycloneran-3,7,10-triol, 7,10S-epoxycycloneran-3,15-diol, 7,10R-epoxycycloneran-3,15-diol, and (10Z)-15-acetoxy-10-cycloneren-3,7-diol, were isolated in addition to the known (10Z)-cyclonerotriol, (10E)-cyclonerotriol, catenioblin C, and chokol E from the culture of Trichoderma asperellum A-YMD-9-2, an endophytic fungus obtained from the marine red alga Gracilaria verrucosa. The structures of previously unreported compounds were established by spectroscopic techniques, including 1D/2D NMR, MS, and IR. The isolation of these new cyclonerane derivatives greatly adds to the structural diversity of unusual cyclonerane sesquiterpenes, and several isolates exhibit potent inhibition against some marine phytoplankton species.


Assuntos
Endófitos/química , Gracilaria/microbiologia , Sesquiterpenos/química , Trichoderma/química , Animais , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fitoplâncton/efeitos dos fármacos , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Zooplâncton/efeitos dos fármacos
9.
Mar Pollut Bull ; 138: 58-62, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30660309

RESUMO

Planktonic sea-urchin larvae actively ingest polyethylene microplastics (MP) that accumulate in the larval stomach and can be distinguished from natural food using polarized light microscopy. MP filtering rates were similar to those of natural particles (microalgae) of the same size range; 0.30 to 0.35 mL min-1. However, the ingestion of MP did not increase the toxicity of a hydrophobic organic chemical, the 4­n­nonylphenol (NP), either in microalgae-fed or starved larvae. The 48 h EC50 of NP was more than two fold higher in fed (158.8 to 190.9 µg L-1) compared to starved larvae (64.3 to 83.7 µg L-1), disregarding the presence and amount of MP, which did not significantly affect larval growth. Therefore, MP did not act as vectors of a hydrophobic chemical such as NP to these planktonic organisms. These results challenge the hypothetical role of MP as vectors of organic contaminants to marine food webs.


Assuntos
Exposição Dietética/efeitos adversos , Fenóis/toxicidade , Polietileno/toxicidade , Ouriços-do-Mar/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Conteúdo Gastrointestinal , Larva/efeitos dos fármacos , Microalgas , Plásticos
10.
Environ Sci Pollut Res Int ; 26(30): 30663-30674, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29946840

RESUMO

As one kind of cheap, environmentally-friendly and efficient treatment materials for direct control of cyanobacterial blooms, modified clays have been widely concerned. The present study evaluated cyanobaterial removal by a red soil-based flocculant (RSBF) with a large enclosure experiment in a tropical mesotrophic reservoir, in which phytoplankton community was dominated by Microcystis spp. and Anabaena spp. The flocculant was composed of red soil, chitosan and FeCl3. Twelve enclosures were used in the experiment: three replicates for each of one control and three treatments RSBF15 (15 mg FeCl3 l-1), RSBF25 (25 mg FeCl3 l-1), and RSBF35 (35 mg FeCl3 l-1). The results showed that the red soil-based flocculant can significantly remove cyanobacterial biomass and reduce concentrations of nutrients including total nitrogen, nitrate, ammonia, total phosphorus, and orthophosphate. Biomass of Microcystis spp. and Anabaena spp. was reduced more efficiently (95%) than other filamentous cyanobacteria (50%). In the RSBF15 treatment, phytoplankton biomass recovered to the level of the control group after 12 days and cyanobacteria quickly dominated. Phytoplankton biomass in the RSBF25 treatment also recovered after 12 days, but green algae co-dominated with cyanobacteria. A much later recovery of phytoplankton until the day of 28 was observed under RSBF35 treatment, and cyanobacteria did no longer dominate the phytoplankton community. The application of red soil-based flocculant greatly reduces zooplankton, especially rotifers, however, Copepods and Cladocera recovered fast. Generally, the red soil-based flocculant can be effective for urgent treatments at local scales in cyanobacteria dominating systems.


Assuntos
Cloretos/farmacologia , Cianobactérias/isolamento & purificação , Recuperação e Remediação Ambiental/métodos , Compostos Férricos/farmacologia , Zooplâncton/efeitos dos fármacos , Anabaena/isolamento & purificação , Animais , Biomassa , China , Quitosana/química , Clorófitas/efeitos dos fármacos , Copépodes/efeitos dos fármacos , Floculação , Microcystis/isolamento & purificação , Nitrogênio/análise , Fósforo/análise , Fitoplâncton , Solo/química , Clima Tropical
11.
Environ Toxicol Chem ; 38(2): 396-411, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30365191

RESUMO

In the present study we performed a microcosm experiment to assess the effects of the insecticide lufenuron on zooplankton communities exposed to increased temperature and drought in (semi-)arid regions. The experiment consisted of 3 environmental scenarios, assessed in 2 parts. Firstly, we assessed how water temperature (20 and 28 °C) affects the sensitivity and resilience of the zooplankton community to lufenuron. Secondly, we investigated the influence of drought on the structure of the zooplankton community at a high water temperature (28 °C) and evaluated its possible interaction with lufenuron. The results show that the community exposed to lufenuron at 28 °C had a faster lufenuron-related response and recovery than the community at 20 °C. The combined effects of lufenuron and temperature resulted in a synergistic effect on some taxa (Daphnia sp., Cyclopoida, and Copepoda nauplii). The tested zooplankton community had a high resilience to drought, although some particular taxa were severely affected after desiccation (Calanoida). Interactions between drought and lufenuron were not statistically significant. However, rewetting after desiccation contributed to lufenuron remobilization from sediments and resulted in a slight Cyclopoida population decline at high exposure concentrations. The study shows how environmental conditions related to global change in (semi-)arid regions may influence chemical fate and the vulnerability of zooplankton communities to chemical stress. Environ Toxicol Chem 2019;38:396-411. © 2018 SETAC.


Assuntos
Benzamidas/toxicidade , Secas , Temperatura Alta , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Copépodes/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Água Doce/química
12.
Ecotoxicology ; 28(1): 26-36, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30460435

RESUMO

Arctic shipping and oil exploration are expected to increase, as sea ice extent is reduced. This enhances the risk for accidental oil spills throughout the Arctic, which emphasises the need to quantify potential consequences to the marine ecosystem and to evaluate risk and choose appropriate remediation methods. This study investigated the sensitivity of Arctic marine plankton to the water accommodated fraction (WAF) of heavy fuel oil. Arctic marine phytoplankton and copepods (Calanus finmarchicus) were exposed to three WAF concentrations corresponding to total hydrocarbon contents of 0.07 mg l-1, 0.28 mg l-1 and 0.55 mg l-1. Additionally, the potential phototoxic effects of exposing the WAF to sunlight, including the UV spectrum, were tested. The study determined sub-lethal effects of WAF exposure on rates of key ecosystem processes: primary production of phytoplankton and grazing (faecal pellet production) of copepods. Both phytoplankton and copepods responded negatively to WAF exposure. Biomass specific primary production was reduced by 6, 52 and 73% and faecal pellet production by 18, 51 and 86% with increasing WAF concentrations compared to controls. The phototoxic effect reduced primary production in the two highest WAF concentration treatments by 71 and 91%, respectively. This experiment contributes to the limited knowledge of acute sub-lethal effects of potential oil spills to the Arctic pelagic food web.


Assuntos
Poluição por Petróleo/efeitos adversos , Fitoplâncton/efeitos dos fármacos , Poluentes Químicos da Água/efeitos adversos , Zooplâncton/efeitos dos fármacos , Animais , Regiões Árticas , Copépodes/efeitos dos fármacos , Copépodes/fisiologia , Fezes/química , Cadeia Alimentar , Fotossíntese/efeitos dos fármacos , Fitoplâncton/fisiologia , Zooplâncton/fisiologia
13.
Chemosphere ; 218: 376-383, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30476769

RESUMO

The study analyzed the correlation between the antibiotic-induced feeding depression and body size reduction in rotifer, Brachionus calyciflorus, involving exposure, post-exposure and re-exposure periods. The filtration and ingestion rates of the rotifers were inhibited in these three exposure periods at any given concentration of the antibiotic sulfamethazine (SMZ). As food for rotifer, the cell size of the green algae was unchanged, which indicated that it could not drive feeding depression. Secondly, several corresponding physiological responses were considered. Reactive oxygen species (ROS) levels increased in the post-exposure and the re-exposure; acetylcholinesterase (AChE) activity was significantly decreased in the exposure and the re-exposure, whereas it was induced in the post-exposure. The activities of amylase and lipase were always inhibited in these three exposure periods. Additionally, significant decreases in lorica length, width and biovolume of rotifers occurred after the feeding depression. Statistical analysis indicated a positive correlation between the activity of the digestive enzyme and the body size. Our results demonstrated that SMZ could influence the neurotransmission, inhibit the activity of the digestive enzyme, and finally result in body size reduction. These results provided an integrated perspective on assessing the toxicity effects of antibiotic in non-lethal dosage on the feeding behavior of non-target aquatic organisms.


Assuntos
Antibacterianos , Tamanho Corporal/efeitos dos fármacos , Digestão/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Zooplâncton/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Rotíferos/efeitos dos fármacos , Sulfametazina/farmacologia , Transmissão Sináptica/efeitos dos fármacos
14.
Environ Sci Pollut Res Int ; 26(2): 1435-1444, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30426375

RESUMO

Tunisia water resources are limited. The country currently has 29 large dams, more than 1000 hill lakes, and 220 small dams which are essential for economic and social development given their contribution to irrigation, drinking water consumption, flooding protection, production of electrical energy, groundwater recharge, and industrial uses. Given the scarcity of these resources, it is crucial to be able to ensure the quality of freshwater environments, particularly those intended for human consumption. In this study, we meant to assess the health status of various freshwater ecosystems in different regions of Tunisia (north and center west) in order to detect genotoxic components in sediments and their potential effect on zooplankton (cladocerans). Sediment and cladoceran species were collected from dams, ponds, and temporary rivers in Tunisia. For each collection site, micronucleus (MN) assay was performed, in triplicates, using a pool of ten specimens of the same cladoceran species. MN occurrence in cladocerans varied from one site to another and MN frequencies varied between 0.67 and 22‰, suggesting the presence of genotoxic substances in certain sites. Sediment genotoxicity and mutagenicity were assessed using the SOS Chromotest and the Ames test. Sediment results showed that genotoxicity varies from one site to another displaying a quantitative and a qualitative variation of pollutant among the sites. These results suggest an urgent need for continuous monitoring of freshwater environments in Tunisia, particularly those intended for drinking water.


Assuntos
Cladóceros/efeitos dos fármacos , Sedimentos Geológicos , Testes de Mutagenicidade/métodos , Zooplâncton/efeitos dos fármacos , Animais , Cladóceros/genética , Ecossistema , Ecotoxicologia/métodos , Água Doce , Testes para Micronúcleos/métodos , Tanques , Rios , Tunísia , Qualidade da Água
15.
Sci Total Environ ; 656: 598-607, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30529964

RESUMO

Magnetic microparticles (MPs) have been recently proposed as innovative and promising dissolved inorganic phosphorus (DIP) adsorbents. However, before using them in a whole-lake restoration project, it is essential to assess their toxicological effects (direct and indirect) on aquatic biota. In the present study we hypothesized that zooplankton community is affected by MPs used for lake restoration. To test our hypothesis we designed a microcosms experiment (n = 15) containing lake water and surface sediment from a hypertrophic lake. Temporal changes (70 days) on physico-chemical conditions and on zooplankton structure (rotifers, copepods and branchiopods) were monitored under different scenarios. In particular, three different treatments were considered: no addition of MPs (control) and MPs addition (1.4 g MPs L-1) on the surface water layer (T-W) and on the sediment (T-S). After 24 h of contact time, MPs were removed with a magnetic rake. A total of 15 zooplankton species (12 rotifers, 1 branchiopod and 2 copepods) were recorded and a high abundance of zooplankton was registered during the experiment for all treatments. No significant differences (RM-ANOVA test; p > 0.05) in total abundance, species richness and species diversity among treatments were found. The absence of any effect of MPs on zooplankton can be explained because MPs did not significantly alter any of its physico-chemical (e.g. temperature, pH, O2) or biological (e.g. food quantity and quality) drivers. These results confirm the suitability of MPs as a promising tool for removing DIP in eutrophic aquatic ecosystems.


Assuntos
Recuperação e Remediação Ambiental/métodos , Lagos/análise , Fósforo/análise , Zooplâncton/fisiologia , Adsorção , Animais , Biota/efeitos dos fármacos , Biota/fisiologia , Fenômenos Magnéticos , Fósforo/química , Espanha , Zooplâncton/efeitos dos fármacos
16.
Artigo em Inglês | MEDLINE | ID: mdl-30509914

RESUMO

Recent discoveries have documented evolutionary responses to freshwater salinization. We investigated if evolutionary responses to salinization exhibit life-history trade-offs or if they can mitigate ecological impacts such as cascading effects through mechanisms of tolerance and cross-tolerance. We conducted an outdoor mesocosm experiment using populations of Daphnia pulex-a ubiquitous algal grazer-that were either naive or had previously experienced selection to become more tolerant to sodium chloride (NaCl). During the initial phase of population growth, we discovered that evolved tolerance comes at the cost of slower population growth in the absence of salt. We found evolved Daphnia populations maintained a tolerance to NaCl approximately 30 generations after the initial discovery. Evolved tolerance to NaCl also conferred cross-tolerance to a high concentration of CaCl2 (3559 µS cm-1) and a moderate concentration of MgCl2 (967 µS cm-1). A higher concentration of MgCl2 (2188 µS cm-1) overwhelmed the cross-tolerance and killed all Daphnia Tolerance to NaCl did not mitigate NaCl-induced cascades leading to phytoplankton blooms, but cross-tolerance at moderate concentrations of MgCl2 and high concentrations of CaCl2 mitigated such cascading effects caused by these two salts. These discoveries highlight the important interplay between ecology and evolution in understanding the full impacts of freshwater salinization.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.


Assuntos
Evolução Biológica , Daphnia/efeitos dos fármacos , Água Doce/química , Traços de História de Vida , Salinidade , Poluentes Químicos da Água/efeitos adversos , Animais , Daphnia/fisiologia , Zooplâncton/efeitos dos fármacos , Zooplâncton/fisiologia
17.
Sci Rep ; 8(1): 16258, 2018 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-30390015

RESUMO

Zooplankton in Antarctic maritime lakes face challenges imposed by anthropogenic chemicals. Studies on temperate species suggest that lipophilic chemicals will accumulate in dormant embryos of Antarctic zooplankton and decrease hatching success, thereby threatening centuries of accumulated genetic diversity that would increase population resilience in the face of climate change. We evaluated the potential for lakes to act as sinks for legacy pollutants in the maritime Antarctic by testing sediments for polychlorinated biphenyls (PCBs) previously identified in soil, flora and fauna of lake catchments. Direct tests of embryo permeability to chemicals are confounded by potential adhesion of chemicals to the embryo surface and limited biomass available. Therefore, in order to assess the potential for lipophilic chemicals to penetrate and passively accumulate in dormant embryos of Antarctic lacustrine zooplankton, we evaluated the effect of anoxia on post-diapause development in the calanoid copepod, Boeckella poppei, and then used chemical anoxia induced by rotenone as a reporter for permeability of these embryos to moderately lipophilic chemicals. The data presented demonstrate that embryos of B. poppei from Antarctic lake sediments will passively accumulate moderately lipophilic chemicals while lying dormant in anoxic sediments. Implications for legacy POPs in sediments of Antarctic maritime lakes are discussed.


Assuntos
Copépodes/metabolismo , Embrião não Mamífero/metabolismo , Sedimentos Geológicos/química , Zooplâncton/metabolismo , Animais , Regiões Antárticas , Hipóxia Celular/efeitos dos fármacos , Mudança Climática , Copépodes/química , Copépodes/efeitos dos fármacos , Copépodes/embriologia , Embrião não Mamífero/efeitos dos fármacos , Monitoramento Ambiental , Poluentes Ambientais/análise , Poluentes Ambientais/toxicidade , Interações Hidrofóbicas e Hidrofílicas , Lagos/microbiologia , Permeabilidade , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Rotenona/farmacologia , Zooplâncton/química , Zooplâncton/efeitos dos fármacos
18.
Mar Pollut Bull ; 135: 17-29, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30301027

RESUMO

Marine and coastal ecosystems are among the largest contributors to the Earth's productivity. Experimental studies have shown negative impacts of microplastics on individual algae or zooplankton organisms. Consequently, primary and secondary productivity may be negatively affected as well. In this study we attempted to estimate the impacts on productivity at ecosystem level based on reported laboratory findings with a modelling approach, using our biogeochemical model for the North Sea (Delft3D-GEM). Although the model predicted that microplastics do not affect the total primary or secondary production of the North Sea as a whole, the spatial patterns of secondary production were altered, showing local changes of ±10%. However, relevant field data on microplastics are scarce, and strong assumptions were required to include the plastic concentrations and their impacts under field conditions into the model. These assumptions reveal the main knowledge gaps that have to be resolved to improve the first estimate above.


Assuntos
Ecossistema , Ecotoxicologia/métodos , Plásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Meio Ambiente , Modelos Teóricos , Mar do Norte , Fitoplâncton/efeitos dos fármacos , Fitoplâncton/crescimento & desenvolvimento , Plásticos/análise , Poluentes Químicos da Água/análise , Zooplâncton/efeitos dos fármacos , Zooplâncton/crescimento & desenvolvimento
19.
Bull Environ Contam Toxicol ; 101(5): 556-561, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30244274

RESUMO

Widespread use of agrochemicals increases their likelihood of entering aquatic systems in mixture. Despite different modes of action, atrazine (herbicide) and tetracycline (antibiotic) adversely affect non-target photosynthetic organisms individually, but the effects of simultaneous exposure to both contaminants are untested. We created microcosms containing microalgae (Chlorella sp.), floating macrophytes (Lemna minor), and a zooplankton grazer (Daphnia magna). Microcosms were exposed to environmentally relevant concentrations of atrazine and tetracycline, alone and together, for 10 days. Atrazine decreased Chlorella sp. abundance, but not enough to reduce food availability to D. magna whose reproduction and mortality were unaffected. In contrast, tetracycline and atrazine appeared to have additive effects on L. minor abundance and growth inhibition. These additive adverse effects suggest increased potential for L. minor population decline over the long term, and potential for altered species interactions in aquatic systems receiving agricultural runoff.


Assuntos
Antibacterianos/toxicidade , Atrazina/toxicidade , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Araceae/efeitos dos fármacos , Chlorella/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Microalgas/efeitos dos fármacos , Zooplâncton/efeitos dos fármacos
20.
Environ Toxicol Chem ; 37(10): 2692-2698, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30187530

RESUMO

Widespread use of pesticides often contaminates natural habitats, exposing nontarget organisms to pesticides that were designed to control pest populations. Even low levels of pesticides can affect aquatic communities both directly and indirectly. Previous work has shown that trace amounts of the pesticide chlorpyrifos altered tadpole morphology and neurodevelopment in artificial ponds (mesocosms). To determine whether effects resulted from direct chlorpyrifos exposure or from disruption of the food web due to a pesticide-induced decline in zooplankton, we examined the impacts of chlorpyrifos on amphibian development in the presence of chlorpyrifos-resistant zooplankton, a key component of the aquatic trophic community. Northern leopard frog (Lithobates pipiens) tadpoles were reared through metamorphosis in mesocosms containing either 0 or 1 µg/L chlorpyrifos and either chlorpyrifos-resistant or chlorpyrifos-sensitive Daphnia pulex zooplankton. Developmental exposure to chlorpyrifos resulted in metamorphs with a relatively wider optic tectum, medulla, and diencephalon compared with controls, and this result was found regardless of the zooplankton population within the mesocosm. Thus, chlorpyrifos directly impacted brain development, independent of the effects on the trophic community. With respect to body shape, chlorpyrifos had no effect on body shape of metamorphs reared in mesocosms with chlorpyrifos-sensitive zooplankton, but body shape was sensitive to zooplankton population in the absence of chlorpyrifos. To conclude, low, ecologically relevant doses of organophosphorous pesticides can directly impact neurodevelopment in a vertebrate model. Environ Toxicol Chem 2018;37:2692-2698. © 2018 SETAC.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/patologia , Clorpirifos/toxicidade , Inseticidas/toxicidade , Rana pipiens/crescimento & desenvolvimento , Animais , Encéfalo/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Ecossistema , Larva/efeitos dos fármacos , Análise de Componente Principal , Zooplâncton/efeitos dos fármacos
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