1,721,231 research outputs found
Nonylphenol in a lagoon environment: 4-nonylphenol and nonylphenol ethoxylates in fish tissues
No full textToxic effects of engineered nanoparticles in the marine environment: model organisms and molecular approaches
No full textEngineered nanoparticles (ENPs) have been produced by nano-biotech companies in recent decades to generate innovative goods in various fields, including agriculture, electronics, biomedicine, manufacturing, pharmaceuticals and cosmetics. The nano-scale size of the particles can confer novel and significantly improved physical, chemical and biological properties to scientific phenomena and processes. As their applications to science and technology expand, the need to understand the putative noxious effects of ENPs on humans and ecosystems is becoming increasingly important. ENPs are emerging as a new class of pollutants with eco-toxicological impacts on marine ecosystems because the particles can end up in waterways and reach the sea. Recent laboratory studies in invertebrates and fishes suggest that exposure to ENPs could have harmful effects. Because there is not much data available for gauging the effects of ENPs on marine wildlife, the ultimate ecotoxicological impacts of chronic exposure to ENPs should be investigated further using laboratory tests and field studies. We propose the use of model organisms to understand the molecular pathways involved in the mechanisms that may be affected by exposure to ENPs. Sensitive and innovative molecular methods will provide information regarding the hazards of ENPs that may exist in the marine environment. Model organisms that have not been conventionally used for risk assessment and the development of eco-toxicogenomic approaches will result in an improved understanding of the mechanistic modes of action of contaminating ENPs in the marine environment. © 2012 Elsevier Ltd
Cholinesterase activities in the adductor muscle of the Antarctic scallop Adamussium colbecki
No full textAntarctica is regarded as one of the most pristine parts of the Earth but even this remote ecosystem is affected by contamination and high levels of certain heavy metals, such as cadmium, which may occur naturally in Antarctic waters. The bivalve scallop Adamussium colbecki is considered a key species of Antarctic benthic ecosystems and a sensitive target for bioaccumulation of xenobiotics and metals. Since cholinesterases (ChEs) in the adductor muscle of A. colbecki presumably play a prominent physiological role through regulation of swimming movements, the main aims of this study was to characterize ChE activities in adductor Muscle of A. colbecki and to investigate their sensitivity to organophosphate pesticides and heavy metals. The results suggest that an acetylcholinesterase-like enzyme in the adductor muscle of the scallop has low sensitivity to organophosphates but was significantly inhibited by exposure to cadmium
Safety and sustainable development of European aquaculture: new tools for an environmentally sound aquaculture
No full textSustainable and long-term growth of the aquaculture industry should involve both ecologically sound practices and appropriate resource management. The increasing economic dimension of Mediterranean aquaculture is opening new economic niches and may be a valid support to reduce the pressure of traditional fisheries. Aquaculture practices can also lead to modifications of coastal habitats through the impact of wastes of land-based and open-sea mariculture facilities. In addition to these aspects which place a direct pressure on aquatic ecosystems and wild fishery resources, a wide range of environmental contaminants, such as chemicals used in farming operations, can accumulate in farmed organisms and put fish health and quality at risk. Thus, as aquaculture makes its transition to a major food-producing sector, proper assessment and control of environmental impacts and food safety awareness are becoming increasingly important. The development of simple tools able to monitor the extent of environmental and biological impacts associated with farming operations at various levels of biological complexity from the ecosystem to the organism level is required. Although a number of techniques for assessing the environmental and biological impact of pollutants in natural ecosystems are available, the development of practical and validated tools is sorely needed in aquaculture
Mixed function oxidase activity and organochlorine levelks in farmed sharpnout seabream (Diplodus puntazzo) from two intensive aquaculture facilities
No full textMixed function oxidase (MFO) activities and organochlorine levels were investigated
in liver of farmed sharpsnout seabream bred in two intensive facilities, a sea farm
and a land-based farm. The aim of this study is to investigate how different facility locations
and breeding conditions might affect fish metabolic capabilities and accumulation of
toxic chemicals in farmed sharpsnout seabream. The differences between breeding two or
more fish species in the same cage or tank known as polyculture and monoculture (1 species)
were also investigated. The results showed that both facility location (sea and land) as
well as breeding systems (polyculture and monoculture) might be responsible for the differences
observed in both MFO enzyme activity and organochlorine levels. Significantly higher
activities of two metabolizing enzymes such as 7-ethoxyresorufin-O-deethylase (EROD) and
benzo(a)pyrene monooxygenase (B(a)PMO) were in fact recorded in land-based farmed fish
than in sea farmed ones, and much higher in those from polyculture than in monoculture
(p<0.05). By contrast, the highest levels of dichlorodiphenyldichloroethilene (ppDDE) and
polychlorinated biphenyls (PCBs as Aroclor 1260) were measured in sea-farmed fish, except
for hexachlorobenzene (HCB), which gave higher levels in land-based farmed fishes. No significant
differences were observed between monoculture and polyculture in p,pDDE and PCBs
levels except for p,pDDE which was significantly higher in monoculture than in polyculture
(p<0.05) in fish reared in tanks. Finally significantly higher HCB levels were measured in
fish reared in monoculture in tanks (p<0.05) and in polyculture in cages (p<0.05). The low
TEQ values obtained for PCB congeners at liver level indicated no concern for fish health
Cholinesterase activities in the scallop Pecten jacobaeus: characterization and effects of exposure to aquatic contaminants
No full textNearshore marine environments of industrialized countries are increasingly threatened by anthropogenic pollution. It is therefore a priority task to investigate the sensitivity of new ecotoxicological warning signals of the occurrence and effects of aquatic pollutants. The main aims of the present study were: 1) to characterize the biochemical properties of ChEs in tissues of the bivalve Pecten jacobaeus, using different specific substrates and selective inhibitors; 2) to measure sensitivity of ChE activities to in vitro exposure to the OPs azamethiphos and DFP and to the heavy metals cadmium and zinc. Our final aim was to carry out a preliminary evaluation of the suitability of ChEs measurement in tissues of the scallop for monitoring marine environmental quality and neurotoxic compounds contamination in the Mediterranean Sea. Responses to specific inhibitors have suggested that ChEs in adductor muscle share many characteristics with vertebrate acetylcholinesterase. Dose-dependent inhibition of ChE was observed in response to in vitro exposure to environmental contaminants such as cadmium and azamethiphos. Sensitivity to zinc and DFP was lower. ChEs in P. jacobaeus might therefore have potential as a sensitive biomarker for monitoring marine pollution. Results of the present study will be useful to focus further experiment of exposure to pollutants under in vivo conditions. Capsule: Cholinesterase activities in scallop Pecten jacobaeus were observed to be sensitive to contaminants in vitro and may therefore have potential as biomarkers for monitoring water pollution. © 2007 Elsevier B.V. All rights reserved
PCB levels in European eel (Anguilla anguilla) from two coastal lagoons of the Mediterranean
No full textEels are exposed to pollutants due to their unusual life cycle and are vulnerable to contamination associated with sediment due to their diet, feeding habits and territoriality. Since the 1980s, a decline in American and European eel populations has been recorded. The causes of this decline still are unknown but pollution from domestic and industrial effluents is known to be involved. Since little data is available on PCB contamination in eels from Italian waters, PCBs were measured in muscle of Anguilla anguilla captured in 2001 in two brackish ecosystems of the Mediterranean: the lagoons of Orbetello and Santa Giusta (Italy). PCBs were higher in samples from Orbetello lagoon than in those detected from Santa Giusta lagoon (P < 0.05). Congener and isomer analyses indicated Aroclor 1260 as a likely source of PCBs in the Orbetello and Santa Giusta samples. Only the toxic equivalents (TEQs) of mono-ortho PCBs were calculated. © Springer Science + Business Media, Inc. 2006
Organochlorines and trace metals exposure and effects in sharpnout seabream cultured in intensive seafarm: a case study on a coastal area of the Tyrrhenian Sea
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