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The role of physico-chemical interactions in the seasonality of toxic dinoflagellate cyst assemblages: The case of the NW Patagonian fjords system النص الكامل
2022
Rodríguez–Villegas, Camilo | Díaz, Patricio A. | Salgado, Pablo | Tomasetti, Stephen J. | Díaz, Manuel | Marín, Sandra L. | Baldrich, Ángela M. | Niklitschek, Edwin | Pino, Loreto | Matamala, Thamara | Espinoza, Katherine | Figueroa, Rosa I.
The role of physico-chemical interactions in the seasonality of toxic dinoflagellate cyst assemblages: The case of the NW Patagonian fjords system النص الكامل
2022
Rodríguez–Villegas, Camilo | Díaz, Patricio A. | Salgado, Pablo | Tomasetti, Stephen J. | Díaz, Manuel | Marín, Sandra L. | Baldrich, Ángela M. | Niklitschek, Edwin | Pino, Loreto | Matamala, Thamara | Espinoza, Katherine | Figueroa, Rosa I.
Harmful algal blooms (HABs) are recurrent in the NW Patagonia fjords system and their frequency has increased over the last few decades. Outbreaks of HAB species such as Alexandrium catenella, a causal agent of paralytic shellfish poisoning, and Protoceratium reticulatum, a yessotoxins producer, have raised considerable concern due to their adverse socioeconomic consequences. Monitoring programs have mainly focused on their planktonic stages, but since these species produce benthic resting cysts, the factors influencing cyst distributions are increasingly gaining recognition as potentially important to HAB recurrence in some regions. Still, a holistic understanding of the physico-chemical conditions influencing cyst distribution in this region is lacking, especially as it relates to seasonal changes in drivers of cyst distributions, as the characteristics that favor cyst preservation in the sediment may change through the seasons. In this study, we analyzed the physico–chemical properties of the sediment (temperature, pH, redox potential) and measured the bottom dissolved oxygen levels in a “hotspot” area of southern Chile, sampling during the spring and summer as well as the fall and winter, to determine the role these factors may play as modulators of dinoflagellate cyst distribution, and specifically for the cysts of A. catenella and P. reticulatum. A permutational analysis of variance (PERMANOVA) showed the significant effect of sediment redox conditions in explaining the differences in the cyst assemblages between spring-summer and fall-winter periods (seasonality). In a generalized linear model (GLM), sediment redox potential and pH were associated with the highest abundances of A. catenella resting cysts in the spring-summer, however it was sediment temperature that most explained the distribution of A. catenella in the fall-winter. For P. reticulatum, only spring-summer sediment redox potential and temperature explained the variation in cyst abundances. The implications of environmental (physico-chemical) seasonality for the resting cysts dynamics of both species are discussed.
اظهر المزيد [+] اقل [-]The role of physico-chemical interactions in the seasonality of toxic dinoflagellate cyst assemblages: The case of the NW Patagonian fjords system
Exploring plastic-induced satiety in foraging green turtles النص الكامل
2020
Santos, Robson G. | Andrades, Ryan | Demetrio, Guilherme Ramos | Kuwai, Gabriela Miki | Sobral, Mañana Félix | Vieira, Júlia de Souza | Machovsky-Capuska, Gabriel E.
In the last decade many studies have described the ingestion of plastic in marine animals. While most studies were dedicated to understanding the pre-ingestion processes involving decision-making foraging choices based on visual and olfactory cues of animals, our knowledge in the post-ingestion consequences remains limited. Here we proposed a theoretical complementary view of post-ingestion consequences, attempting to connect plastic ingestion with plastic-induced satiety. We analyzed data of plastic ingestion and dietary information of 223 immature green turtles (Chelonia mydas) from tropical Brazilian reefs in order to understand the impacts of plastic ingestion on foraging behavior. Generalized linear mixing models and permutational analysis of variance suggested that plastic accumulations in esophagus, stomach and intestine differed in their impact on green turtle’s food intake. At the initial stages of plastic ingestion, where the plastic still in the stomach, an increase in food intake was observed. The accumulation of plastic in the gastrointestinal tract can reduce food intake likely leading to plastic-induced satiety. Our results also suggest that higher amounts of plastics in the gastrointestinal tract may led to underweight and emaciated turtles. We hope that adopting and refining our proposed framework will help to clarify the post-ingestion consequences of plastic ingestion in wildlife.
اظهر المزيد [+] اقل [-]Influence of exposure time on phosphorus composition and bioavailability in wetland sediments from Poyang lake, since the operation of the Three Gorges Dam النص الكامل
2020
Ni, Zhaokui | Wang, Shengrui | Wu, Yue | Liu, Xiaofei | Lin, Ripeng | Liu, Zhezhe
The role of exposure time on wetland sediment-bound phosphorus (P) biogeochemical behavior is studied in Lake Poyang after the operation of the Three Gorges Dam (TGD). The multiple P compounds primarily include orth–P (88.3%), mono–P (8.9%), DNA–P (2.1%), and pyro–P (0.8%) in the exposed sediments. A significant decreasing trend of orth–P occurred after the operation of the Three Gorges Dam (TGD), with the mean concentration decreasing from 175.9 to 142.5 mg kg⁻¹ from 2007 to 2012 (ANOVA: P < 0.05), whereas the temporal change in biogenic P showed great variability. The plant distribution pattern and the increase in plant biomass due to decreased water levels might be the reason that caused variations in the P species. Furthermore, the content of orth–P, mono–P, DNA–P, and pyro–P showed increasing trends as sediment exposure time increased. However, the enzyme hydrolysis rate of DNA–P decreased with exposure time and may cause the bioavailability of biogenic P to decrease. Despite the fact that the bioavailability of biogenic P might decline in the short term, the favorable environmental conditions for P release in sediment rewetting processes, together with the increase in orth–P and biogenic P due to extended exposure time, indicate that these large additions of P would enter the overlying water and cause water quality decline once the sediment is submerged underwater during the next wet season. An environmental process analysis showed that the increased exposure time induced sediment environmental conditions changes that played an important role in the biogeochemical cycle of P and may be an important way of P replenishment in Lake Poyang. The results of this study help provide a better understanding of the role of sediment drying/wetting cycles in nutrient biogeochemical behavior and fates in wetland ecosystems.
اظهر المزيد [+] اقل [-]Ecotoxicological risk assessment for the herbicide glyphosate to non-target aquatic species: A case study with the mussel Mytilus galloprovincialis النص الكامل
2018
Glyphosate (GLY) is one of the most used herbicide worldwide. Considering that information concerning the impact of GLY on bivalves is scarce, in this study we evaluated for the first time the effects of environmentally realistic concentrations of GLY (10, 100 and 1000 μg/L) to the mussel Mytilus galloprovincialis. Mussels were exposed for 7, 14 and 21 days and several biomarkers were measured in haemocytes/haemolymph (total haemocyte counts, haemocyte diameter and volume, haemolymph pH, haemolymph lactate dehydrogenase activity, haemocyte lysate lysozyme and acid phosphatase activities), as well as in gills and digestive gland (antioxidant enzyme and acetylcholinesterase activities). The concentrations of GLY and its main metabolite aminomethylphosphonic acid in the experimental tanks were also measured. The MANOVA analysis demonstrated that the experimental variables considered (exposure concentration, exposure duration, and their interaction) affected significantly biomarker responses. In addition, the two-way ANOVA analysis indicated that GLY was able to affect most of the cellular parameters measured, whereas antioxidant enzyme activities resulted to be influenced moderately. Interestingly, exposure to GLY reduced significantly acetylcholinesterase activity in gills. Although preliminary, the results of this study demonstrated that GLY can affect both cellular and biochemical parameters in mussels, highlighting a potential risk for aquatic invertebrates.
اظهر المزيد [+] اقل [-]Fatty acid composition, enzyme activities and metallothioneins in Donax trunculus (Mollusca, Bivalvia) from polluted and reference sites in the Gulf of Annaba (Algeria): Pattern of recovery during transplantation النص الكامل
2018
Rabei, Amina | Hichami, Aziz | Beldi, Hayet | Bellenger, Sandrine | Khan, Naim Akhtar | Soltani, Noureddine
The gulf of Annaba, the most important touristic and economic coastal zone located in Northeast Algeria, is contaminated by several pollutants from urban, agricultural, harbor and industrial activities. Elevated levels of heavy metals were detected in a locally prevalent edible mollusk Donax trunculus (Bivalvia, Donacidae) widely used as a sentinel species for the assessment of marine pollution. The present work aims to measure the difference between two localities, one being full of different pollutants (Sidi Salem) and the other being relatively clean (El Battah) and to evaluate the ability of D. trunculus to overcome the environmental stress during a transplantation experiment by a determination of fatty acid profile, the enzymes activities and the level of metallothioneins (MTs), a biomarker of metallic contamination. Adults of D. trunculus were collected at Sidi Salem (contaminated site) and transplanted into El Battah (reference site) for 21 days in cages (60 × 60 × 60 cm with a 2 mm mesh). Biochemical analyzes were conducted at different times (0, 7, 14 and 21 days). At 0-day experiment: the rate of the fatty acids, the enzymes activities and MT levels at the site of Sidi Salem (polluted site) were significantly different from those of El Battah. During the transplantation a gradual restoration of fatty acids rates, enzymes activities and MT levels was observed. At the end of the period of transplantation, the values are comparable to those of El Battah. A two-way ANOVA (time, site) on data revealed significant effects of time and site. Overally, D. trunculus is able to induce its detoxification system and to restore relatively rapidly the status of individuals from the reference site (El Battah).
اظهر المزيد [+] اقل [-]Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism النص الكامل
2017
Gómez-Canela, Cristian | Prats, Eva | Piña, Benjamí | Tauler, Romà
Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism النص الكامل
2017
Gómez-Canela, Cristian | Prats, Eva | Piña, Benjamí | Tauler, Romà
In this work the effect of chlorpyrifos exposure on metabolic profiles of zebrafish muscle was evaluated by liquid chromatography coupled to high resolution mass spectrometry. Different chemometric tools based on the selection of Regions of Interest and on Multivariate Curve-Resolution-Alternating Least Squares are proposed for the analysis of the complex data sets generated in the different exposure experiments. Analysis of Variance Simultaneous Component Analysis of changes on metabolite peak profile areas showed significant chlorpyrifos concentration and exposure time-dependent changes, clearly differentiating between exposed and non-exposed samples and between short (2 h) and long exposure times (6 h or 24 h). The changes observed in the concentrations of 50 muscle metabolites are indicative of induction of oxidative stress, of a general disruption of neurotransmitter metabolism, and of muscle exhaustion. These three effects are intimately related to the toxicity of chlorpyrifos.
اظهر المزيد [+] اقل [-]Assessment of chlorpyrifos toxic effects in zebrafish (Danio rerio) metabolism
Influence of 2,4-D and MCPA herbicides on uptake and translocation of heavy metals in wheat (Triticum aestivum L.) النص الكامل
2017
Skiba, Elżbieta | Kobyłecka, Joanna | Wolf, Wojciech M.
The aim of the study was to estimate the influence of the 2,4-dichlorophenoxy acetic acid and 2-methyl-4-chlorophenoxyacetic acid on the uptake and translocation of Cd, Co, Ni, Cu, Zn, Pb and Mn by wheat (Triticum aestivum L.). Two farmland soils typical for the central Polish rural environment were used. Studies involved soil analyses, contents of bioavailable, exchangeable and total forms for all investigated metals. Atomic absorption spectrometry was used to determine the concentration of the elements. The best correlation between the herbicide rate and the metal concentration was visibly for the underground part of plants. Analysis of variance proved that herbicide treatment of wheat frequently influences the metal transfer from soil and their concentration in roots and shoots. In particular, higher herbicide rates prompted the significant increase of all metals concentration in roots. Additionally, transfer coefficients depended on the type of soil and the herbicide rate applied. Uptake of metals may be also influenced by the formation of sparingly water-soluble metal-herbicide complexes. Its intensity would then depend on the solubility of particular chemical entity with the low solvable Pb, Cu and Cd complexes being the least mobile.
اظهر المزيد [+] اقل [-]Seasonal occurrence of antibiotics and a beta agonist in an agriculturally-intensive watershed النص الكامل
2015
Jaimes-Correa, Juan C. | Snow, Daniel D. | Bartelt-Hunt, Shannon L.
We evaluated the occurrence of 12 veterinary antibiotics and a beta agonist over spatial and temporal scales in Shell Creek, an intensively agricultural watershed in Nebraska, using Polar Organic Chemical Integrative Samplers (POCIS). Twelve pharmaceuticals were detected with concentrations ranging from 0.0003 ng/L to 68 ng/L. The antibiotics measured at the highest time-weighted average concentrations were lincomycin (68 ng/L) and monensin (49 ng/L), and both compounds were detected at increased concentrations in summer months. Analysis of variance indicates that mean concentrations of detected pharmaceuticals have no significant (p > 0.01) spatial variation. However, significant temporal differences (p < 0.01) were observed. This study demonstrates the utility of passive samplers such as POCIS for monitoring ambient levels of pharmaceuticals in surface waters.
اظهر المزيد [+] اقل [-]Bioaccumulation and depuration of metals in blue crabs (Callinectes sapidus Rathbun) from a contaminated and clean estuary النص الكامل
2010
Reichmuth, Jessica M. | Weis, Peddrick | Weis, Judith S.
Blue crabs from a contaminated estuary (Hackensack Meadowlands-HM) and a cleaner reference site (Tuckerton-TK) were analyzed for Cr, Cu, Hg, Pb, and Zn in muscle and hepatopancreas. Crabs from each site were taken into the laboratory and fed food from the other site, or in another experiment, transplanted to the other site for eight weeks. All crabs were analyzed for metals. Overall, tissue concentrations reflected environmental conditions. Tissue differences were found for Cu, Pb and Zn (all higher in hepatopancreas), and Hg (higher in muscle). HM muscle had more Hg than TK muscle, but did not decrease after transplanting or consuming clean food. HM crabs lost Cu, Pb and Zn in hepatopancreas after being fed clean food or transplanted. TK crabs increased Hg in muscle and Cr and Zn in hepatopancreas after transplantation or being fed contaminated (HM) food. Concentrations were variable, suggesting that blue crabs may not be fully reliable bioindicators of polluted systems. The accumulation of metals within the muscle and hepatopancreas of blue crabs was highly variable, but often followed environmental concentrations.
اظهر المزيد [+] اقل [-]Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands – A controlled mesocosm experiment النص الكامل
2010
Penha-Lopes, Gil | Bartolini, Fabrizio | Limbu, Samwel | Cannicci, Stefano | Mgaya, Yunus | Kristensen, Erik | Paula, Jose
The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3–4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential. Terebralia palustris high ecosystem engineering potential in constructed mangrove wetlands.
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