1,720,969 research outputs found
Effect of heavy metals on morphological characteristics of Taraxacum officinale Web growing on mine soils in NE Italy. J. Geochem. Explor., 123, 101-108.
No full textPlants growing on metal contaminated soils can uptake heavy metals and accumulate them in their tissues; the accumulation of potentially toxic elements can produce adverse effects on plant morphology and health. In this study, plants of Taraxacum officinale Web growing on mixed sulphides (Cu, Fe, Pb, Zn) mine waste in NE Italy were studied in order to assess the levels of potentially toxic heavy metals (Cd, Cr, Cu, Fe, Pb, Zn) in plants in relation to soil, and to investigate the accumulation ability and morphological response to environmental stress. T. officinale accumulates relatively high amounts of different metals in both shoots and roots, with positive translocation factor (TF. ≥. 1). Micromorphological observations on the leaf anatomy of contaminated plants revealed significant reduction in the leaf thickness, changes in intercellular spaces and in cell structural organization in comparison to plants grown on unpolluted soil. The recorded morphological changes appear to be related to contamination levels in soils. © 2012 Elsevier B.V
Infectious Parasites in Coral Reef Fish and Their Potential Use for Habitat Quality Assessment in Jordan’s Gulf of Aqaba, Red Sea
Full text linkIncidents of parasitic infections of coastal (0–40m deep) fish species were investigated to assess ecosystem health and stability along Jordan’s Gulf of Aqaba (GoA). The aim was to compare sites of probable anthropogenic impacts using the extent of infections and species richness indices. A total of 828 fish belonging to 60 species were collected and examined from 7 sites. Fish were brought to laboratory and examined for skin and gill lesions and/or parasites. Fish necropsy was undertaken to assess organ-specific parasitic infections. The infection prevalence (IV) of 8 disease agents pooled from all sites was Psuedodactylogyrus sp., Dactylogyrus sp., Copepod (Gnathia sp.), Ergasilus sp., Maxillopoda, Nematodes (Anisakis sp), Isopods and Platy helminthes. The highest IV was reported in fish gills by Flukes (helminthes), and Isopods and monogeneans were recorded in 88% of the examined fish. However, the highest % of infection was the copepods, Ergasilus sp. and Psuedodactylogyrus sp., while the lowest % was the helminthes (fish flukes). The gut parasites pseudodactylogyrus sp. and dactelogyrus sp. prevailed highest in fish collected at northern sits of GoA. These together with one nematode dominated sites of increasing urban activities. By comparing species richness indices of heteroxenous vs. monoxenous parasites in some fish, results suggest increased incidents of monoxenous parasite in fish collected at areas likely impacted by human activities along the coast
Potential toxicity assessment of anthropogenic pressure by heavy metals in semi-enclosed artificial lagoon ecosystems in the Gulf of Aqaba, Red Sea
Full text linkToxicity Assessment of Contaminated Soils from a Mining Area in Northeast Italy by Using Lipid Peroxidation Assay.
Full text linkContamination by heavy metals in soils may strongly affect the environmental quality. Lipid peroxidation
caused by heavy metals in plants was investigated as a relevant bioassay of toxicity. Soils and wild plants
(dandelion and willow) were collected from an abandoned mine area in northeast Italy, and the concentration
of different heavy metals (Ni, Cr, Cu, Pb, Zn, Fe and Mn) were measured and analyzed. Soils affected by
mining activities presented total Zn, Cu, and Pb concentrations (2566, 3975, 20,815 mg kg−1 respectively)
above toxic thresholds, and 58% for Fe. Heavy metal-induced oxidative stress was evidenced by the generation
of reactive radicals, followed by an increase in malondialdehyde (MDA) production up to 41.64 μM in
willow leaves. We found that MDA concentration in plant tissues differed significantly among species and
plant organs. The higher concentration of metal in soil corresponded with the higher concentration of
MDA in the plant. The combined results of metal concentration, MDA content and translocation coefficients
in plants show that the investigated plants are rather highly tolerant towards environmental pollution.
This suggests that they could be useful in phytoremediation of metal contaminated sites
The pedological heritage of the Dolomites (Northern Italy): Features, distribution and evolution of the soils, with some implications for land management.
Full text linkDiversity and dynamics of seaweed associated microbial communities inhabiting the lagoon of venice
Full text linkSeaweeds are a group of essential photosynthetic organisms that harbor a rich diversity of associated microbial communities with substantial functions related to host health and defense. Environmental and anthropogenic stressors may disrupt the microbial communities and their metabolic activity, leading to host physiological alterations that negatively affect seaweeds’ performance and survival. Here, the bacterial communities associated with one of the most common seaweed, Ulva laetevirens Areshough, were sampled over a year at three sites of the lagoon of Venice affected by different environmental and anthropogenic stressors. Bacterial communities were characterized through Illumina sequencing of the V4 hypervariable region of 16S rRNA genes. The study demonstrated that the seaweed associated bacterial communities at sites impacted by environmental stressors were host-specific and differed significantly from the less affected site. Furthermore, these communities were significantly distinct from those of the surrounding seawater. The bacterial communities’ composition was significantly correlated with environmental parameters (nutrient concentrations, dissolved oxygen saturation, and pH) across sites. This study showed that several more abundant bacteria on U. laetevirens at stressed sites belonged to taxa related to the host response to the stressors. Overall, environmental parameters and anthropogenic stressors were shown to substantially affect seaweed associated bacterial communities, which reflect the host response to environmental variations
Protective Properties of Milk Thistle in Aquaculture: A Study on its Role in Mitigating Supracide-Induced Stress in Fish
Full text linkThis investigation sought to comprehensively evaluate the protective properties of Milk Thistle seeds against Supracide-induced oxidative stress in the Marbled Spinefoot fish. Liquid chromatography–mass spectrometry (LC–MS) was employedto identify metabolites present in Silybum marianum seeds. The LC50 value of organophosphorous insecticide wasdetermined as 7.5 μg L-1 through a 24-hour bath exposure. The experimental setup involved a 14-day dietarysupplementation of S. marianum seeds followed by exposure to the determined Supracide LC50. Various physiologicalparameters, including lipid degradation, Alanine aminotransferase (ALT), Lactate dehydrogenase (LDH), and Totalcholesterol (T.ch) levels, were measured to assess fish health and stress. Additionally, histopathological examinations wereconducted on the hepatopancreas tissues of both normal and stressed fish. The obtained results indicated significant increases(P<0.05) in serum ALT and LDH activities in the group of fish exposed to the toxin. Moreover, the levels of lipidperoxidation products in hepatopancreas homogenates were significantly higher (P<0.05) in the exposed fish group, exceptfor total cholesterol, which exhibited a significant decrease. Histological analysis further revealed notable tissuemodifications in the examined organs, while the control group of fish exhibited normal appearance. Taken together, thesefindings suggest that Milk thistle seeds may possess protective effects against Supracide-induced oxidative stress inchallenged S. rivulatus fish. As a result, this study provides valuable insights into potential alternative ameliorating agentsfor addressing aquaculture contamination caused by organophosphate insecticides
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