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Resultados 1791-1800 de 4,309
Effects of metal contamination on the gene expression profile of two benthic species: Cerastoderma edule and Ruditapes philippinarum Texto completo
2017
This study aimed to identify new biomarkers for metal exposure in two bivalve species. Suppressive Subtractive Hybridization (SSH) was employed to evaluate the transcriptomic response of Cerastoderma edule and Ruditapes philippinarum to metal pollution. Protein synthesis and catalytic activity were the most affected metabolic processes in C. edule and R. philippinarum, respectively. Also, different genes responded to the effect of contamination in each species. The different response observed in both species reinforces the importance of including more than one bioindicator species in risk assessment studies. These results provide the basis for new studies, which are necessary for further validation of the use of the identified genes as molecular biomarkers for metal exposure.
Mostrar más [+] Menos [-]Floating marine litter as a raft for drifting voyages for Planes minutus (Crustacea: Decapoda: Grapsidae) and Liocarcinus navigator (Crustacea: Decapoda: Polybiidae) Texto completo
2017
Tutman, P. | Kapiris, K. | Kirinčić, M. | Pallaoro, A.
The Columbus crab Planes minutus and Arch-fronted swimming crab Liocarcinus navigator, within their distribution ranges in the Mediterranean, were found rafted on plastic macro-litter floating on the open south Adriatic. While P. minutus was recorded from inanimate flotsam outside of the Mediterranean, L. navigator is herein reported for the first time on floating marine litter. The role of floating litter as habitat or as a dispersal agent for marine invertebrates has received quite attention however, records of decapod crabs drifting on litter has been relatively sparse. Our results suggests that vast quantities of floating debris, comprised primarily of non-biodegradable plastic polymers, probably will augment natural floating substrates in the marine environment, potentially facilitating the spread of invasive species. The dispersion of rafting crabs through floating debris should be investigated given the high potential ecological risk of invasion by exotic species due to the increase in waste production (ecological risk assessment).
Mostrar más [+] Menos [-]Environmental consequences of the flooding of the Bay Park Sewage Treatment Plant during Superstorm Sandy Texto completo
2017
Swanson, R Lawrence | Wilson, Robert | Brownawell, Bruce | Willig, Kaitlin
Failure of the Bay Park Sewage Treatment Plant (STP) during Superstorm Sandy led to adverse effects in the waters of Hempstead Bay, Long Island, NY. These appear to be related to large discharges of partially treated sewage through its primary and auxiliary outfalls. Modeled dilution discharges indicate that sewage infiltrated the bay, remaining up to 10days. Water column impacts included salinity and dissolved oxygen declines, and biological oxygen demand and nitrogen concentration increases. While the STP does not appear to have released fecal coliform, there were elevated levels of enterococci within the bay for a considerable period following the storm, probably from multiple sources.The STP's reduced functioning and associated environmental impacts, even with resilience upgrades, are not conducive to removing the bay from the list of Impaired Water Bodies. The results reinforce the need to transfer the discharge from the existing outfall to the ocean.
Mostrar más [+] Menos [-]Determination of hydrocarbons transported by urban runoff in sediments of São Gonçalo Channel (Pelotas – RS, Brazil) Texto completo
2017
Sanches Filho, Pedro J. | Böhm, Emerson M. | Böhm, Giani M.B. | Montenegro, Gissele O. | Silveira, Lucas A. | Betemps, Glauco R.
A high concentration of hydrocarbons in the environment is indicative of pollution. To evaluate the effect of hydrocarbons transported by urban runoff, the present study analyzed total petroleum hydrocarbons (TPHs), aliphatic hydrocarbons (AHs), unresolved complex mixture (UCM), and n-alkanes of the sediments of the canal that cross the urban area of Pelotas, Rio Grande do Sul, Brazil. The carbon preference index (CPI), terrigenous/aquatic ratio (TAR), and pristane/phytane ratio were determined. The TPH content ranged from 177,043.7μg·kg−1±13.4% to 5,892,667.0μg·kg−1±5.9%. The total aliphatic content ranged from 116,268.8μg·kg−1±11.1% to 2,393,592.6μg·kg−1±7.7%, indicating chronic contamination of n-alkanes petrogenic and biogenic sources. The levels of hydrocarbons (TPH, AHs, and n-alkanes) were considered relatively high, confirming the effect of urban runoff on the drainage system of cities and their consequent effect on the estuarine region of Patos Lagoon and other water resources.
Mostrar más [+] Menos [-]Elevated gonadal atresia as biomarker of endocrine disruptors: Field and experimental studies using Mytilus trossulus (L.) and 17-alpha ethinylestradiol (EE2) Texto completo
2017
Smolarz, Katarzyna | Hallmann, Anna | Zabrzańska, Sandra | Pietrasik, Anna
In the present work we compared the type and frequency of gonadal abnormalities among Mytilus trossulus populations from the Gulf of Gdańsk, Baltic Sea. Observed histopathologies were grouped as regressive changes (RC, gonadal atresia (GA) and regression (GR)), progressive changes (PC, gonadal tumors) and intersex. Sex-based and spatial differences in frequency of RC were found, with the highest frequency of RC and PC found in mussels from polluted station B followed by mussels from station A located near a purification plant outlet. Bivalves from the reference area had the lowest frequency of RC.In order to confirm biomarker applicability of RC, an exposure experiment with model xenoestrogen 17α-ethinylestradiol (EE2) was performed. The exposure of M. trossulus to 50 and 500ngdL−1 of EE2 resulted in an increased frequency of gonadal regression and atresia, including melanized hemocytes infiltration in seminiferous tubules. We thus suggest that these changes can serve as biomarkers of endocrine disrupting compounds in biomonitoring studies.
Mostrar más [+] Menos [-]A Systematic Review on Bioelectrochemical Systems Research Texto completo
2017
Ghangrekar, M. M. | Chatterjee, Pritha
Bioelectrochemical systems (BESs) convert the energy present in wastewater to recover resources like bioelectricity, hydrogen, nutrients, heavy metals, minerals, and industrial chemicals. Various aspects of BES have been discussed here along with their applications and other advantages towards bioenergy recovery. More scientifically organized cross-discipline research efforts are required to scale-up these systems and to get benefit of recovering useful energy from waste materials. Full-scale implementation of bioelectrochemical wastewater treatment is complicated because certain microbiological, technological, and economic challenges need to be resolved that have not previously been encountered in any other wastewater treatment system. BES has higher prospects for in situ remediation of polluted water body or marshy soils and sediments. This technology is likely to evolve as a way of treating sewage, industrial, or agricultural wastewater, not only by lowering the amount of energy required, but at the same time producing electricity, hydrogen, or other chemicals of high value. Thus, after improving the performance of the BES, widening the scope for products recovery by developing better understanding of the process and with efforts to reduce its production cost, it can become a sustainable technology for treatment of wastewater with added advantage of recovery of resources and bioenergy.
Mostrar más [+] Menos [-]SMART marine goals, targets and management – Is SDG 14 operational or aspirational, is ‘Life Below Water’ sinking or swimming? Texto completo
2017
Cormier, Roland | Elliott, Michael
The United Nations Sustainable Development Goals (SDG), adopted in September 2015, are accompanied by targets which have to be met individually and collectively by the signatory states. SDG14 Life Below Water aims to lay the foundation for the integrated and sustainable management of the oceans. However, any environmental management has to be based around targets which are SMART – specific, measurable, achievable, realistic and time bounded – otherwise it is not possible to determine whether management actions are successful and achieve the desired aims. The discussion here shows that many of the targets adopted for SDG14, and especially a detailed analysis of Target 1, are aspirational rather than fully quantified. In order to move towards making the targets operational, we advocate merging the language of environmental management with that used by industry for linking risks to the environment, management performance and ensuing controls. By adopting an approach which uses Key Performance Indicators (‘KPIs’), Key Risk Indicators (‘KRIs’) and Key Control Indicators (‘KCIs’), we advocate that a degree of rigour leading to defendable actions can be brought to marine management.
Mostrar más [+] Menos [-]Assessing marine environmental status through microphytobenthos assemblages colonizing the Autonomous Reef Monitoring Structures (ARMS) and their potential in coastal marine restoration Texto completo
2017
Pennesi, Chiara | Danovaro, Roberto
Microphytobenthos is potentially highly sensitive to environmental alterations, but has been rarely utilized in monitoring studies. Here we investigated the use of microphytobenthos colonizing Autonomous Reef Monitoring Structures (ARMS) to assess the marine environmental quality. We analysed microphytobenthic assemblages in terms of abundance, biomass and species composition on ARMS deployed in northern Adriatic Sea along a gradient of increasing impacts. We show that microphytobenthic variables changed significantly across sites, with lowest abundance and biodiversity in the highly impacted site. Moreover, the specific analysis of Diatoms revealed that genera like Entomoneis and Cylindrotheca could be used as indicators of nutrient enriched and stressed conditions. We provide evidence that the analysis of microphytobenthos colonizing artificial substrates could be used as a tool for detecting altered environmental characteristics. We also show that the ARMS, recreating hot spots of microphytobenthic biodiversity, and protect them from grazing, could be potentially utilized to restore degraded hard substrates. Our result indicates that microphytobenthos can be easily incorporated in future monitoring and restoration programmes to assess and improve marine environmental health.
Mostrar más [+] Menos [-]A new perspective of particle adsorption: Dispersed oil and granular materials interactions in simulated coastal environment Texto completo
2017
Meng, Long | Bao, Mutai | Sun, Peiyan
This study, adsorption behaviors of dispersed oil in seawaters by granular materials were explored in simulation environment. We quantitatively demonstrated the dispersed oil adsorbed by granular materials were both dissolved petroleum hydrocarbons (DPHs) and oil droplets. Furthermore, DPHs were accounted for 42.5%, 63.4%, and 85.2% (35.5% was emulsion adsorption) in the adsorption of dispersed oil by coastal rocks, sediments, and bacterial strain particles respectively. Effects of controlling parameters, such as temperature, particle size and concentration on adsorption of petroleum hydrocarbons were described in detail. Most strikingly, adsorption concentration was followed a decreasing order of bacterial strain (0.5–2μm)>sediments (0.005–0.625mm)>coastal rocks (0.2–1cm). With particle concentration or temperature increased, adsorption concentration increased for coastal rocks particle but decreased for sediments particle. Besides, particle adsorption rate of petroleum hydrocarbons (n-alkanes and PAHs) was different among granular materials during 60 days.
Mostrar más [+] Menos [-]Rainfall contributes ~30% of the dissolved inorganic nitrogen exported from a southern Great Barrier Reef river basin Texto completo
2017
Packett, Robert
A study was conducted to estimate how much of the annual load of dissolved inorganic nitrogen (DIN) from Great Barrier Reef (GBR) river basins could come from rainfall. Results suggest rainfall contributed ~37% of the average annual DIN load from the Fitzroy Basin over three wet seasons. Rainfall DIN contribution at plot to sub-catchment scale ranged from 5 to >100% for study sites in the Fitzroy and Pioneer Basins. An estimate using measured and modelled data indicates ~28% of the longer-term average annual DIN load from the entire GBR catchment may originate from rainfall. These estimates may affect current GBR management and water quality targets. Numerous studies predict increases in atmospheric nitrogen pollution from Asia via fossil fuel combustion and more frequent severe La Nina events via global warming. Future GBR rainfall chemistry data may be required for assessing catchment management outcomes and regional trends in atmospheric DIN deposition.
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