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Increasing salinization of freshwater limits invasiveness of a live-bearing fish: Insights from behavioral and life-history traits Texte intégral
2022
Zhou, Linjun | Liu, Kai | Zhao, Yu | Cui, Ling | Dong, Chenglong | Wang, Zaizhao
Biological invasions and continued salinization of freshwater are two global issues with largely serious ecological consequences. Increasing salinity in freshwater systems, as an environmental stressor, may negatively affect normal life activities in fish. It has been documented that salinity limits the invasive success of alien species by mediating physiological and life-history performances, however, there are few studies on how salinity affects its invasive process via altered behaviors. Using wild-caught invasive western mosquitofish (Gambusia affinis) as animal model, in this study, we asked whether gradual increasing salinity affects behaviors (personality and mate choice decision here), life-history traits, as well as the correlation between them by exposing G. affinis to three levels salinity (freshwater, 10 and 20‰). Results showed that, with increased salinity, male tended to be shyer, less active, less sociable, and reduced desire to mate, and female tended to be shyer, less active and lost preferences for the larger male. Furthermore, across salinity treatments, male exhibited reduced body fat content and rising reproduction allocation, however, pregnant female revealed diametrically opposed trends. In addition, the correlation between life-history traits and behaviors was only identified in pregnant female. It seems that either salinity or life-history traits directly affects mosquitofish behaviors. In summary, our results partially emphasize the harmful consequences of salinity on both life-history traits and behavioral performances. These findings provide a novel perspective on how salinity potentially affect fish fitness via altering personalities, mate choice decisions, as well as body condition, and hence supports the idea that salinity could affect the spread of invasive mosquitofish.
Afficher plus [+] Moins [-]Tadpoles of the horned frog Ceratophrys ornata exhibit high sensitivity to chlorpyrifos for conventional ecotoxicological and novel bioacoustic variables Texte intégral
2018
Salgado Costa, C. | Ronco, A.E. | Trudeau, V.L. | Marino, D. | Natale, G.S.
Previous studies reported that some species of the family Ceratophryidae are able to produce sounds during premetamorphic tadpole stages. We have now determined the effects of the cholinesterase-inhibiting insecticide chlorpyrifos (CPF) on sounds emitted by tadpoles of Ceratophrys ornata. Tadpoles were exposed individually in order to evaluate the progression of effects. Effects on sound production were complemented with common ecotoxicological endpoints (mortality, behavior, abnormalities and growth inhibition). C. ornata was found to be more sensitive than other native (= 67%, 50%) and non-native species (= 75%, 100%) considering lethal and sublethal endpoints, respectively. Effects on sounds appear along with alterations in swimming, followed by the presence of mild, then severe abnormalities and finally death. Therefore, sound production may be a good biomarker since it anticipates other endpoints that are also affected by CPF. Ceratophrys ornata is a promising new model species in ecotoxicology.
Afficher plus [+] Moins [-]Foliar mercury content from tropical trees and its correlation with physiological parameters in situ Texte intégral
2018
Teixeira, Daniel C. | Lacerda, Luiz D. | Silva-Filho, Emmanoel V.
The terrestrial biogeochemical cycle of mercury has been widely studied because, among other causes, it presents a global distribution and harmful biotic interactions. Forested ecosystems shows great concentrations from Hg and Litterfall is known as the major contributor to the fluxes at the soil/air interface, through the superficial adsorption on the leaves and by the gas exchange of the stomatal pores. The understanding of which processes control the stage of Hg cycle in these ecosystems is still not totally clear. The influences of physiological and morphological parameters were tested against the Hg concentrations in the leaves of 14 endemic species of an evergreen tropical forest in south-eastern Brazil, and an exotic species from Platanus genus. Pathways were studied through leaf areas and growing tree parameters, where maximum rate of net photosynthesis (Pnmax), transpiration rate (E), stomatal conductance (Gs) were examined. The results obtained in situ indicated a positive correlation between Pnmax and the Hg concentration; Cedrela fissilis and Croton floribundus were the most sensitive species to the accumulation of Hg and the most photosynthetically active in this study. The primary productivity from Tropical forest should be a proxy of Hg deposition from atmosphere to soil, retained there while forests stand up, representing an environmental service of sequestration of this global pollutant. Therefore, forests and trees with great photosynthetic potential should be considered in predictions, budgets and non-geological soil content regarding the global Hg cycle.
Afficher plus [+] Moins [-]What does impacted look like? High diversity and abundance of epibiota in modified estuaries Texte intégral
2015
Clark, Graeme F. | Kelaher, Brendan P. | Dafforn, Katherine A. | Coleman, Melinda A. | Knott, Nathan A. | Marzinelli, Ezequiel M. | Johnston, Emma L.
Ecosystems modified by human activities are generally predicted to be biologically impoverished. However, much pollution impact theory stems from laboratory or small-scale field studies, and few studies replicate at the level of estuary. Furthermore, assessments are often based on sediment contamination and infauna, and impacts to epibiota (sessile invertebrates and algae) are seldom considered. We surveyed epibiota in six estuaries in south-east Australia. Half the estuaries were relatively pristine, and half were subject to internationally high levels of contamination, urbanisation, and industrialisation. Contrary to predictions, epibiota in modified estuaries had greater coverage and were similarly diverse as those in unmodified estuaries. Change in epibiota community structure was linearly correlated with sediment-bound copper, and the tubeworm Hydroides elegans showed a strong positive correlation with sediment metals. Stressors such as metal contamination can reduce biodiversity and productivity, but others such as nutrient enrichment and resource provision may obscure signals of impact.
Afficher plus [+] Moins [-]Biological pollution
1993
McKnight, Bill N.
"The combination of natural habitat loss and the introduction of invasive exotic animal and plant species is creating environmental chaos. Because of the magnitude of the problem and the urgent need for action, the Indiana Academy of Science (IAS) organized this symposium. The conference dealt with both aquatic and terrestrial systems, with specific focus on causes, control measures, management practices, ecologic and economic consequences, and policy." "The Academy was founded in 1885 and deals with both biological and physical science. The IAS is dedicated to promote scientific research and the diffusion of scientific information; to encourage communication and cooperation among scientists; to improve education while stimulating interest in the sciences. It does so by offering research grants, sponsoring education activities and organizations, publishing a journal and books, and presenting special topic conferences."--BOOK JACKET.
Afficher plus [+] Moins [-]A review on pesticides in flower production: A push to reduce human exposure and environmental contamination Texte intégral
2021
Pereira, Patrícia C.G. | Parente, Cláudio E.T. | Carvalho, Gabriel O. | Torres, João P.M. | Meire, Rodrigo O. | Dorneles, Paulo R. | Malm, Olaf
In several countries, flower import regulations are restricted to food security, by establishing maximum residue limits (MRL) for pesticides in flower-based food products and biosafety, in order to limit the circulation of vectors, pests and exotic species across borders. In this context, the lack of limits on pesticides in flower-products for ornamental purposes can influence the pesticide overuse in production areas, as well as the transfer of contaminated products between countries. Therefore, the purpose of this review was to discuss possible adverse effects on human and environmental health of pesticides used in floriculture, evaluating regulations on the use of these pesticides in the main importing and flower-producing countries. This review included 92 documents. The use of 201 compounds was identified by interviews and analytical measurements. Among them, 93 are banned by the European Union (EU), although 46.3 % of these compounds have been identified in samples from European countries. Latin American countries have a large number of scientific publications on pesticides in flower production (n = 51), while the EU and China have less studies (n = 24) and the United States and Japan have no studies. Regarding adverse health effects, poorer neurobehavioral development, reproductive disorders, congenital malformations and genotoxicity have been reported for residents of flower production areas and workers throughout the flower production cycle. Studies including water samples show overuse of pesticides, while environmental impacts are related to water and air contamination, soil degradation and adverse effects on the reproduction and development of non-target organisms. This review points out that the absence of MRL for non-edible flowers can be crucial for the trade of contaminated products across borders, including pesticides banned in importing countries. Furthermore, setting limits on flowers could reduce the use of pesticides in producing countries.
Afficher plus [+] Moins [-]Marine invertebrate larvae love plastics: Habitat selection and settlement on artificial substrates Texte intégral
2020
Pinochet, Javier | Urbina, Mauricio A. | Lagos, Marcelo E.
Global urbanization and plastic pollution has increased the availability and variety of substrates for sessile organisms, and are intensively used by invasive species for settlement. Despite extensive literature describing the strong association between artificial structures and invasive species, little effort has been directed towards identifying the larval traits that favor this selection. Larval selection and settlement are crucial as larvae actively search and interpret environmental cues to identify suitable habitats to settle. The aim of this research was to investigate if invertebrate larvae have a preference for a particular anthropogenic substrate, and how pre-settlement behaviors vary when encountering different substrates. We used two invasive bryozoan species, Bugula flabellata and Bugula neritina, which are commonly found in urbanized areas around the world. Energy expenditure during planktonic and benthonic stages, pre-settlement swimming/exploring behaviors, settlement and larval selectivity were quantified under laboratory conditions on different substrates (concrete, wood, polystyrene, polyvinyl chloride, polyethylene terephthalate and polycarbonate). The energy expenditure measured was higher in planktonic larvae than in early settled larvae. Larvae of both species swam less and explored more when exposed to plastic surfaces, suggesting a preference for this substrate and resulting in lower energy expenditures associated with searching for habitat. Larvae actively chose to settle on plastics rather than on wood or concrete substrates. The results suggest that for Bugula larvae, the likelihood of colonizing plastic surfaces is higher than other materials commonly found in urbanized coastal areas. The more quickly they adhere to artificial substrates the lower the energy expenditure, contributing to higher fitness in these individuals. The strong preference of invertebrate larvae for plastics can potentially extend the distribution range of many invasive marine species as they are able to travel long distances attached to floating debris. This phenomenon will likely exacerbate the introduction of exotic species into novel habitats.
Afficher plus [+] Moins [-]Effects of soil nutrient variability and competitor identify on growth and co-existence among invasive alien and native clonal plants Texte intégral
2020
Zhao, Cong-Ying | Liu, Yuanyuan | Shi, Xue-Ping | Wang, Yong-Jian
Changes in soil nutrients variability could significantly interact with other global change processes (such as community dynamics, biological invasion). Global exchange and accumulation of alien species caused environmental and economic threats in the introduced ranges. Their invasion success or not in local plant communities is largely depended on the interactions and competitive outcomes with other species and environmental conditions. Here, we tested whether the interactions of nutrient variability and competitor identity influence plant performance, potential invasion success of invasive species and their co-existence with native species. In both greenhouse and field experiment, we subjected three congeneric and naturally co-occurring pairs of invasive alien and native clonal plants in China to different nutrient variability (constant high, multiple pulses and/or single pulse) and competitor identity (intra-specific competitors, native competitors, invasive competitors and both native & invasive competitors). Our results showed that total biomass or the increase of cover of invasive species was significantly larger than those of the native species regardless of competitor identity. Native competitors significantly decreased biomass proportion of native species, but did not affect that of invasive species. The whole community with invasive target species accumulated more total biomass than with native species under multiple pulses nutrient when with the native competitors. Invasive species produced significantly higher biomass proportion than natives under all competitor identity treatments except for native & invasive competitors. Multiple mixed competitors (i.e. native & invasive competitors) decreased the plant performance and dominance of invasive target species, to some extent, thus construction of multi-species competition might facilitate coexistence of native and invasive species in communities. Interactions between native competitors or native & invasive competitors, and nutrient variability play important roles in plant performance and potential invasion success in communities. Multiple invasional interference may have significant implications for the co-existence of invasive and native species, and for management of invasive species.
Afficher plus [+] Moins [-]Phytoremediation of polluted soils and waters by native Qatari plants: Future perspectives Texte intégral
2020
Al-Thani, R.F. | Yasseen, B.T.
Because pollution is predicted to worsen and sources of quality water for agriculture and other human activities are limited, many countries have been motivated to seek novel water sources. Qatar relies on groundwater and water desalinization to meet its water needs, and additional water resources will be needed to avoid unexpected crises in the future. Industrial wastewater (IWW) is an alternative water source, and much research activities should be focused on developing innovative and contemporary approaches to removing pollutants from IWW. Phytoremediation methods, shown to be efficient methods of removing and degrading contaminants of various kinds from polluted waters and soils, require knowledge of the native plants and associated microorganisms. In Qatar, many native plants (monocot and dicot, indigenous or introduced) have been shown to be greatly effective in remediating polluted areas. This article is a guide for Qatari scientists aiming to identify promising native plants and associated microbes for IWW phytoremediation. In it, we review the basic components of bioremediation and summarize the principle phytoremediation approaches and preferred recycling options. The multiple mechanisms and methods of phytoremediation for cleansing polluted soils and waters are also discussed as are details of the metabolic reactions degrading the organic components of oil and gas. Finally, heavy metal accumulation is addressed. Wastewater from industrial and domestic activities is currently being used to create green areas around Doha, Qatar, and such areas could be at risk of contamination. Many native Qatari plants and soil-dwelling microbes are efficient at removing organic and inorganic contaminants from polluted soils and waters, and some are promising candidates for achieving a clean environment free of contaminants.
Afficher plus [+] Moins [-]Development of water quality criteria for phenanthrene and comparison of the sensitivity between native and non-native species Texte intégral
2015
Wu, Jiang-Yue | Yan, Zhen-Guang | Liu, Zheng-Tao | Liu, Ji-dong | Liang, Feng | Wang, Xiao-Nan | Wang, Weili
Phenanthrene (PHE) is a priority polycyclic aromatic hydrocarbon (PAH) which is toxic to aquatic organisms. However, there has been no paper dealing with water quality criteria (WQC) of PHE due to the shortage of toxicity data of different taxonomic levels. In the present study, toxicity data were obtained from 8 acute toxicity tests and 3 chronic toxicity tests using 8 Chinese native aquatic species from different taxonomic levels, and the water quality criteria was derived using 3 methods. Furthermore, differences of species sensitivity distributions (SSDs) between native and non-native species were compared. A criterion maximum concentration of 0.0514 mg/L and a criterion continuous concentration of 0.0186 mg/L were developed according to the US EPA guidelines. Finally, by using risk quotient (RQ) to assess the site-specific ecological risk in Liao River, the results indicated that the PHE might pose no risk to local aquatic species.
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