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Distribution and sources of aliphatic hydrocarbons in surface sediments of Sergipe River estuarine system Full text
2012
Lima, Manoel B. | Feitosa, Elaine A. | Emídio, Elissandro S. | Dórea, Haroldo S. | Alexandre, Marcelo R.
The assessment of aliphatic hydrocarbons was performed in the Sergipe River estuarine system, northeastern Brazil. Aliphatic hydrocarbons concentration ranged from 9.9ugg⁻¹ up to 30.8ugg⁻¹ of dry sediment. The carbon preference index (CPI, based on nC₂₄ to nC₃₄ range), indicated predominance of petrogenic input in two of the sites analyzed (P4 and P5). The unresolved complex mixture (UCM) was found to be present in seven of the nine sites sampled (except for P4 and P5). Overall, the results of this work suggest that there is a mix of organic matter sources to the sediment. Although the coast of Sergipe has an intense off shore petroleum exploration and the Sergipe River crosses the entire city of Aracaju, the capital city of Sergipe, non-significant anthropogenic fingerprint was assessed.
Show more [+] Less [-]Ostreopsis cf. ovata (Dinophyta) bloom in an equatorial island of the Atlantic Ocean Full text
2012
Nascimento, Silvia Mattos | França, Julia Vitor | Gonçalves, José E.A. | Ferreira, Carlos E.L.
The epi-benthic dinoflagellate Ostreopsis cf. ovata Fukuyo has an increasingly global distribution. In Brazil there are reports of O. cf. ovata along the coast from 8°S to 27°S latitude and blooms have been registered on the Rio de Janeiro coastline. In the current study, an O. cf. ovata bloom is reported at Saint Paul’s Rocks (0°55′10″N; 29°20′33″W), between the southern and northern hemispheres. The Archipelago is not inhabited and not subjected to eutrophication, due to isolation, and sustains a number of endemic species. Therefore, blooms of O. cf. ovata may potentially cause demise to trophic chains by affecting marine invertebrates and vertebrates.
Show more [+] Less [-]The use of diatom assemblages as ecological indicators in highly stratified estuaries and evaluation of existing diatom indices Full text
2012
Rovira, L. | Trobajo, R. | Ibáñez, C.
Diatom indices are used to evaluate the ecological status of rivers but they have been rarely applied in estuaries. This study aimed to identify the diatom species indicating the main environmental gradients and pressures in a highly stratified estuary; and to evaluate the applicability of existing freshwater diatom indices. Marine influence due to salt-wedge intrusion and sea water mixing appeared as the main factor affecting diatom community. Three diatom assemblages were identified: indicators of riverine conditions (without marine influence), indicators of estuarine conditions (heterogeneous conditions with higher conductivities due to marine influence) and those specifically indicating well-established salt-wedge situations. Nowadays, the main human pressure affecting diatom community in the Ebro Estuary is the hydrological alteration resulting from flow regulation and abstraction. Several limitations were encountered in the application of diatom indices (e.g. inverse response with nutrients; ecologically important species not considered). Therefore, their use in estuaries should be done cautiously.
Show more [+] Less [-]Indicators of sediment and biotic mercury contamination in a southern New England estuary Full text
2012
Taylor, David L. | Linehan, Jennifer C. | Murray, David W. | Prell, Warren L.
Total mercury (Hg) and methylmercury (MeHg) were analyzed in near surface sediments (0–2cm) and biota (zooplankton, macro-invertebrates, finfish) collected from Narragansett Bay (Rhode Island/Massachusetts, USA) and adjacent embayments and tidal rivers. Spatial patterns in sediment contamination were governed by the high affinity of Hg for total organic carbon (TOC). Sediment MeHg and percent MeHg were also inversely related to summer bottom water dissolved oxygen (DO) concentrations, presumably due to the increased activity of methylating bacteria. For biota, Hg accumulation was influenced by inter-specific habitat preferences and trophic structure, and sediments with high TOC and percent silt–clay composition limited mercury bioavailability. Moreover, hypoxic bottom water limited Hg bioaccumulation, which is possibly mediated by a reduction in biotic foraging, and thus, dietary uptake of mercury. Finally, most biota demonstrated a significant positive relationship between tissue and TOC-normalized sediment Hg, but relationships were much weaker or absent for sediment MeHg. These results have important implications for the utility of estuarine biota as subjects for mercury monitoring programs.
Show more [+] Less [-]An assessment of residence times of land-sourced contaminants in the Great Barrier Reef lagoon and the implications for management and reef recovery Full text
2012
Brodie, Jon | Wolanski, Eric | Lewis, Stephen | Bainbridge, Zoë
We argue that the residence times of key pollutants exported to the Great Barrier Reef (GBR) are greater in the GBR lagoon than those of the water itself, in contradiction to some previous assumptions. Adverse effects of the pollutant discharge will be greater and longer lasting than previously considered, in turn requiring stronger or more urgent action to remediate land practices. Residence times of fine sediments, nitrogen and phosphorus, pesticides and trace metals are suggested to be from years to decades in the GBR lagoon and highly likely to be greater than the residence time of water, estimated at around 15–365days. The recovery of corals and seagrass in the central region of the GBR following current land-use remediation in the catchment depends on the residence time of these contaminants. Ecohydrological modeling suggests that this recovery may take decades even with adequate levels of improved land management practices.
Show more [+] Less [-]The eutrophication commandments Full text
2012
Fulweiler, R.W. | Rabalais, N.N. | Heiskanen, A.S.
Typically, rising atmospheric carbon dioxide concentrations are used to illustrate how humans have impacted the earth. However, we have also dramatically altered the amount of nitrogen (N) and phosphorus (P) cycling through the biosphere. Eventually these nutrients are carried to coastal receiving waters where they cause severe, often negative consequences including increased phytoplankton and macroalgae blooms, loss of submerged aquatic vegetation, low oxygen events, and decreased biodiversity. In many systems mitigation efforts are now underway to return these ecosystems to a less impacted state. While many uncertainties about the best way to manage eutrophic systems remain it is clear that we must take action to lessen our human nutrient footprint. Based on our current understanding of eutrophic systems we present ten eutrophication commandments or guidelines as a tool for scientists, policy makers, managers, and the public.
Show more [+] Less [-]The oil spill model OILTRANS and its application to the Celtic Sea Full text
2012
Berry, Alan | Dąbrowski, Tomasz | Lyons, Kieran
The oil spill model OILTRANS and its application to the Celtic Sea Full text
2012
Berry, Alan | Dąbrowski, Tomasz | Lyons, Kieran
This paper describes details of an oil spill model, OILTRANS, developed by the authors. The model is an off-line particle-transport model coupled to the most up to date operational met-ocean model forecasts. Formulations for the dominant oil fate processes of spreading, advection, diffusion, evaporation, emulsification and dispersion have been encoded, providing the model with the ability to accurately predict the horizontal movement of surface oil slick, the vertical entrainment of oil into the water column and the mass balance of spilled oil. The application of the OILTRANS model to an accidental release during a ship-to-ship fuel transfer in the Celtic Sea in February 2009 is presented to validate the system. Comparisons with aerial observations of the oil slick at the time of the incident, and subsequent model simulations, indicate that the OILTRANS model is capable of accurately predicting the transport and fate of the oil slick.
Show more [+] Less [-]The oil spill model OILTRANS and its application to the Celtic Sea Full text
2012
Berry, Alan | Dabrowski, Tomasz | Lyons, Kieran
NOTICE: this is the author’s version of a work that was accepted for publication in Marine Pollution Bulletin. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Marine Pollution Bulletin, [Volume 64, Issue 11, (November 2012)] doi:10.1016/j.marpolbul.2012.07.036 | This paper describes details of an oil spill model, OILTRANS, developed by the authors. The model is an off-line particle-transport model coupled to the most up to date operational met-ocean model forecasts. Formulations for the dominant oil fate processes of spreading, advection, diffusion,evaporation, emulsification and dispersion have been encoded, providing the model with the ability to accurately predict the horizontal movement of surface oil slick, the vertical entrainment of oil into the water column and the mass balance of spilled oil. The application of the OILTRANS modelto an accidental release during a ship-to-ship fuel transfer in the Celtic Sea in February 2009 is presented to validate the system. Comparisons with aerial observations of the oil slick at the time ofthe incident, and subsequent model simulations, indicate that the OILTRANS model is capable of accurately predicting the transport and fate of the oil slick.
Show more [+] Less [-]Organotin levels in Nazaré canyon (west Iberian Margin, NE Atlantic) and adjacent coastal area Full text
2012
Sousa, Ana C.A. | Oliveira, Isabel B. | Laranjeiro, Filipe | Takahashi, Shin | Tanabe, Shinsuke | Cunha, Marina R. | Barroso, Carlos M.
Organotin levels in Nazaré canyon (west Iberian Margin, NE Atlantic) and adjacent coastal area Full text
2012
Sousa, Ana C.A. | Oliveira, Isabel B. | Laranjeiro, Filipe | Takahashi, Shin | Tanabe, Shinsuke | Cunha, Marina R. | Barroso, Carlos M.
Organotin compounds (OTs) are ubiquitous in the marine environment and high concentrations (μgg⁻¹ range) in sediments from different coastal areas around the world have been reported. However, few reports have described the OTs contamination status in the offshore and deep sea environment. This work investigated organotin levels in Nazaré canyon for the first time. Levels of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT), dioctyltin (DOT) and trioctyltin (TOT) were quantified in sediment samples from the upper flanks of the canyon and from the adjacent coastal area. TBT levels detected in the canyon flanks are about two to three orders of magnitude lower than those found in the coastal area. Nevertheless, when quantifiable, TBT levels in the canyon samples were higher than the Environmental Assessment Criteria set for TBT in sediments by the OSPAR Commission indicating that at those locations negative ecological impacts are likely to occur.
Show more [+] Less [-]Organotin levels in Nazare canyon (west Iberian Margin, NE Atlantic) and adjacent coastal area Full text
1000
Sousa, Ana C. A. | Oliveira, Isabel B. | Laranjeiro, Filipe | Takahashi, Shin | Tanabe, Shinsuke | Cunha, Marina R. | Barroso, Carlos M.
Organotin compounds (OTs) are ubiquitous in the marine environment and high concentrations (mu g g(-1) range) in sediments from different coastal areas around the world have been reported. However, few reports have described the OTs contamination status in the offshore and deep sea environment. This work investigated organotin levels in Nazare canyon for the first time. Levels of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT), triphenyltin (TPT), dioctyltin (DOT) and trioctyltin (TOT) were quantified in sediment samples from the upper flanks of the canyon and from the adjacent coastal area. TBT levels detected in the canyon flanks are about two to three orders of magnitude lower than those found in the coastal area. Nevertheless, when quantifiable. TBT levels in the canyon samples were higher than the Environmental Assessment Criteria set for TBT in sediments by the OSPAR Commission indicating that at those locations negative ecological impacts are likely to occur. (C) 2011 Elsevier Ltd. All rights reserved.
Show more [+] Less [-]Multi-scale distribution and dynamics of bivalve larvae in a deep atoll lagoon (Ahe, French Polynesia) Full text
2012
Thomas, Y. | Garen, P. | Bennett, A. | Le Pennec, M. | Clavier, J.
Multi-scale distribution and dynamics of bivalve larvae in a deep atoll lagoon (Ahe, French Polynesia) Full text
2012
Thomas, Y. | Garen, P. | Bennett, A. | Le Pennec, M. | Clavier, J.
Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550m⁻³ in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial vertical migration correlated with food concentration. Variations in larval abundance were driven by bivalve reproductive activity correlated with meteorological conditions (i.e. windy periods). Finally, relationship between bivalve larvae patterns and pearl oyster (Pinctada margaritifera) settlement structuring is discussed.
Show more [+] Less [-]Multi-scale distribution and dynamics of bivalve larvae in a deep atoll lagoon (Ahe, French Polynesia) Full text
2012
Thomas, Yoann | Garen, Pierre | Bennett, Auguste | Le Pennec, Marcel | Clavier, Jacques
Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550 m(-3) in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial vertical migration correlated with food concentration. Variations in larval abundance were driven by bivalve reproductive activity correlated with meteorological conditions (i.e. windy periods). Finally, relationship between bivalve larvae patterns and pearl oyster (Pinctada margaritifera) settlement structuring is discussed. (C) 2012 Elsevier Ltd. All rights reserved.
Show more [+] Less [-]Biomarkers responses in muscle of Senegal sole (Solea senegalensis) from a heavy metals and PAHs polluted estuary Full text
2012
Oliva, Milagrosa | Perales, José Antonio | Gravato, Carlos | Guilhermino, Lucia | Galindo-Riaño, María Dolores
Biomarkers responses in muscle of Senegal sole (Solea senegalensis) from a heavy metals and PAHs polluted estuary Full text
2012
Oliva, Milagrosa | Perales, José Antonio | Gravato, Carlos | Guilhermino, Lucia | Galindo-Riaño, María Dolores
The biochemical responses in muscle, such as the enzymatic activities of acetylcholinesterase, lactate dehydrogenase and isocitrate dehydrogenase, were studied in sole (Solea senegalensis) collected in Huelva estuary (SW Spain), in the vicinity of a petrochemical and mining industry. The sampling sites showed different type and degree of pollution. The results demonstrated significant differences in muscle activities of AChE and IDH in Odiel and Tinto Rivers compared to control fish. LDH activity did not show any difference between sampling sites. Significant correlations were established between some biomarkers and heavy metals: AChE was correlated with Pb, Cd and Cu concentrations in water; IDH activity was correlated with Cd and Cu concentrations in water and As, Pb and Cd concentrations in sediments; LDH activity was correlated with As and Zn concentration in water and Cd concentration in sediment. Only one correlation was established between the biomarkers analysed and the concentrations of PAHs: benzo(b)fluoranthene concentration in sediment and IDH.
Show more [+] Less [-]Biomarkers responses in muscle of Senegal sole (Solea senegalensis) from a heavy metals and PAHs polluted estuary. Full text
2012
Oliva Ramírez, Milagrosa | Perales Vargas-Machuca, José Antonio | Gravato, Carlos | Guilhermino, Lucía | Galindo Riaño, María Dolores | Tecnologías del Medio Ambiente
The biochemical responses in muscle, such as the enzymatic activities of acetylcholinesterase, lactate dehydrogenase and isocitrate dehydrogenase, were studied in sole (Solea senegalensis) collected in Huelva estuary (SW Spain), in the vicinity of a petrochemical and mining industry. The sampling sites showed different type and degree of pollution. The results demonstrated significant differences in muscle activities of AChE and IDH in Odiel and Tinto Rivers compared to control fish. LDH activity did not show any difference between sampling sites. Significant correlations were established between some biomarkers and heavy metals: AChE was correlated with Pb, Cd and Cu concentrations in water; IDH activity was correlated with Cd and Cu concentrations in water and As, Pb and Cd concentrations in sediments; LDH activity was correlated with As and Zn concentration in water and Cd concentration in sediment. Only one correlation was established between the biomarkers analysed and the concentrations of PAHs: benzo(b)fluoranthene concentration in sediment and IDH.
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