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Pathogenic fungi: An unacknowledged risk at coastal resorts? New insights on microbiological sand quality in Portugal
2011
Sabino, Raquel | Veríssimo, Cristina | Cunha, Maria Ana | Wergikoski, Bela | Ferreira, Filipa C. | Rodrigues, Raquel | Parada, Helena | Falcão, Leonor | Rosado, Laura | Pinheiro, Catarina | Paixão, Eleonora | Brandão, João
Whilst the potential impact on beach users from microorganisms in water has received considerable attention, there has been relatively little investigation into microbial contaminants in sand. Thirty three beaches across Portugal were analyzed during a five year period (2006–2010) to determine the presence of yeasts, pathogenic fungi, dermatophytes, total coliforms, Escherichia coli and intestinal enterococci in sand. Our results showed that 60.4% of the samples were positive for fungi and that 25.2% were positive for the bacterial parameters. The most frequent fungal species found were Candida sp. and Aspergillus sp., whereas intestinal enterococci were the most frequently isolated bacteria. Positive associations were detected among analyzed parameters and country-regions but none among those parameters and sampling period. Regarding threshold values, we propose 15cfu/g for yeasts, 17cfu/g for potential pathogenic fungi, 8cfu/g for dermatophytes. Eighty four cfu/g for coliforms, 250cfu/g for E. coli, and 100cfu/g for intestinal enterococci.
Afficher plus [+] Moins [-]Effects of macroalgal blooms on carbon and nitrogen biogeochemical cycling in photoautotrophic sediments: An experimental mesocosm
2011
García-Robledo, E. | Corzo, A.
The effects of floating macroalgae (250gDWm⁻²) on photoautotrophic microbenthos were studied in a flow-through mesocosm with a parallel mesocosm without macroalgae serving as Control. Vertical microprofiles of O₂ at the sediment–water interface showed a immediate and complete suppression of photosynthetic activity of microphytobenthos (MPB) under the macroalgal canopy, resulting in a shift of benthic metabolism from autotrophic to heterotrophic. MPB abundance and chlorophyll a content decreased and a change from a diatom-dominated to cyanobacteria-dominated community was observed. Inorganic nitrogen nutrients´ concentrations increased in the porewater as a result of the inhibition of MPB nutrient demand, leading to an increase in net ammonification and anaerobic NOₓ ⁻ consumption rates. No organic matter transfer from macroalgae to the sediment was detected, resulting in a net consumption of the carbon and nitrogen stored in the sediment. In consequence, sediment was progressively impoverished in nitrogen, reducing sediment nutrient regeneration.
Afficher plus [+] Moins [-]Decrease of Zn, Cd and Pb concentrations in marine fish species over a decade as response to reduction of anthropogenic inputs: The example of Tagus estuary
2011
Raimundo, Joana | Pereira, Patrícia | Caetano, Miguel | Cabrita, Maria Teresa | Vale, Carlos
Concentrations of Zn, Cd and Pb were measured in muscle of pelagic, demersal and benthic fishes, captured in the coastal area adjoining the Tagus estuary (Portugal), in 1998 and 2010. Additionally, Pb and Cd were determined in estuarine waters, showing a pronounced decrease between 1999 and 2010. Accordingly, specimens captured in 2010 presented significantly lower metal concentrations than individuals caught in 1998. Reductions were more evident for Pb (reduction of 59–99%) than for Cd (14–93%) and Zn (17–54%). Values in pelagic and demersal species exhibited higher reductions than in benthic species. Decrease of metal concentrations in fish appears thus to reflect the improvement of estuarine water quality as anthropogenic sources have been reduced or eliminated. Furthermore, it emphasises the usefulness of the descriptor “Contaminants in Fish” to assess the efficiency of measures to achieve a good environmental status, in the scope of the Marine Strategy Framework Directive.
Afficher plus [+] Moins [-]Perfluorinated alkyl acids in water, sediment and wildlife from Sydney Harbour and surroundings
2011
Thompson, Jack | Roach, Anthony | Eaglesham, Geoff | Bartkow, Michael E. | Edge, Katelyn | Mueller, Jochen F.
Perfluorinated alkyl compounds (PFCs) including perfluorooctane sulphonate (PFOS) and perfluorooctanoate (PFOA) were measured in environmental samples collected from around Homebush Bay, an urban/industrial area in the upper reaches of Sydney Harbour and Parramatta River estuary. Water, surface sediment, Sea Mullet (Mugil cephalus), Sydney Rock Oyster (Saccostrea commercialis) and eggs of two bird species; White Ibis (Threskiornis molucca), and Silver Gull (Larus novaehollandiae) were analysed. In most samples PFOS was the dominant PFC. Geometric mean PFOS concentrations were 33ng/gww (wet weight) in gull eggs, 34ng/gww in ibis eggs, and 1.8ng/gww and 66ng/gww in Sea Mullet muscle and liver, respectively. In sediment the PFOS geometric mean was 1.5ng/g, in water average PFOS and PFOA concentrations ranged from 7.5 to 21ng/L and 4.2 to 6.4ng/L, respectively. In oysters perfluorododecanoic acid was most abundant, with a geometric mean of 2.5ng/gww.
Afficher plus [+] Moins [-]Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in harbor sediments from Sea Lots, Port-of-Spain, Trinidad and Tobago
2011
Mohammed, Azad | Peterman, Paul | Echols, Kathy | Feltz, Kevin | Tegerdine, George | Manoo, Anton | Maraj, Dexter | Agard, John | Orazio, Carl
Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in nearshore marine surficial sediments from three locations in Trinidad. Sediments were sampled at Sea Lots on the west coast, in south Port-of-Spain Harbor, south of Sea Lots at Caroni Lagoon National Park, and on Trinidad’s east coast at Manzanilla. Total PCB concentrations in Sea Lots sediments ranged from 62 to 601ng/g (dry weight {dw}), which was higher than at Caroni and Manzanilla, 13 and 8ng/g dw, respectively. Total OCP concentrations at Sea Lots were ranged from 44.5 to 145ng/g dw, compared with 13.1 and 23.8n/g (dw), for Caroni and Manzanilla respectively. The concentrations of PCBs and of some OCPs in sediments from Sea Lots were above the Canadian interim sediment quality guidelines. To date, this data is the first report on the levels of PCBs and other organochlorine compounds from Trinidad and Tobago.
Afficher plus [+] Moins [-]Assessment of health safety from ingestion of natural radionuclides in seafoods from a tropical coast, India
2011
Khan, M Feroz | Godwin Wesley, S.
The activities of ²¹⁰Po and ²¹⁰Pb were determined in commonly consumed seafoods to evaluate the internal exposure and risk to humans residing Kudankulam coast where a mega nuclear power plant is under construction. The concentration of ²¹⁰Po in seafoods ranged from 1.2±0.7 to 248±8.1Bqkg⁻¹. Meanwhile, ²¹⁰Pb ranged between 1.1±0.05 and 14.8±1.6Bqkg⁻¹. The committed effective dose (CED) due to ²¹⁰Po and ²¹⁰Pb varied from 11.04 to 515.6 and 3.93 to 23.5μSvyr⁻¹, respectively. The lifetime cancer risk for the public due to ²¹⁰Po was in the range of 3.47×10⁻⁵–1.62×10⁻³ and it was 4.03×10⁻⁵–1.96×10⁻⁴ due to ²¹⁰Pb. The activity intake, effective dose and cancer risk was found lesser than international guidelines and the seafood intake was considered to be safe for human consumption.
Afficher plus [+] Moins [-]Do long lived seabirds reduce the negative effects of acute pollution on adult survival by skipping breeding? A study with European storm petrels (Hydrobates pelagicus) during the “Prestige” oil-spill
2011
Zabala, Jabi | Zuberogoitia, Iñigo | Martínez-Climent, Jose Antonio | Etxezarreta, Jon
We estimated the survival probability of breeding European storm petrels before, during and after a severe oil-spill. We hypothesized that petrels might have deserted the breeding colony to maximize their own survival probability and we expected no major change on adult survival probabilities as a consequence of the spill. We used an information-theoretical approach and multi-model inference to assess the strength of the evidence in favour of different hypotheses. Evidence contained in the data clearly supported the non-effect of the spill on adult survival hypothesis while punctual impact of the spill on survival and expanded (3years) impact alternatives received less support. The effect size of the spill on averaged survival estimates was negligible in every case. We suggest that petrels minimized the impact of acute pollution by not investing in reproduction. We suggest that short-medium term management actions after oil-spills and similar catastrophes should focus on ecosystem restoration.
Afficher plus [+] Moins [-]Species- and size-specific variability of mercury concentrations in four commercially important finfish and their prey from the northwest Atlantic
2011
Staudinger, Michelle D.
Total mercury was analyzed as a function of body length, season, and diet in four commercially and recreationally important marine fish, bluefish (Pomatomus saltatrix), goosefish (Lophius americanus), silver hake (Merluccius bilinearis), and summer flounder (Paralichthys dentatus), collected from continental shelf waters of the northwest Atlantic Ocean. Mercury levels in the dorsal muscle tissue of 115 individuals ranged from 0.006 to 1.217μg/g (wet weight) and varied significantly among species. The relationship between predator length and mercury concentration was linear for bluefish and summer flounder, while mercury levels increased with size at an exponential rate for silver hake and goosefish. Mercury burdens were the highest overall in bluefish, but increased with size at the greatest rate in silver hake. Seasonal differences were detected for bluefish and goosefish with mercury levels peaking during summer and spring, respectively. Prey mercury burdens and predator foraging habits are discussed as the primary factors influencing mercury accumulation.
Afficher plus [+] Moins [-]Macrobenthos habitat mapping in a tidal flat using remotely sensed data and a GIS-based probabilistic model
2011
Choi, Jong-Kuk | Oh, Hyun-Joo | Koo, Bon Joo | Lee, Saro | Ryu, Joo-Hyung
This paper proposes and tests a method of producing macrofauna habitat potential maps based on a weights-of-evidence model (a probabilistic approach) for the Hwangdo tidal flat, Korea. Samples of macrobenthos were collected during field work, and we considered five mollusca species for habitat mapping. A weights-of-evidence model was used to calculate the relative weights of 10 control factors that affect the macrobenthos habitat. The control factors were compiled as a spatial database from remotely sensed data combined with GIS analysis. The relative weight of each factor was integrated as a species potential index (SPI), which produced habitat potential maps. The maps were compared with the surveyed habitat locations, revealing a strong correlation between the potential maps and species locations. The combination of a GIS-based weights-of-evidence model and remote sensing techniques is an effective method in determining areas of macrobenthos habitat potential in a tidal flat setting.
Afficher plus [+] Moins [-]Status of macrobenthic community of Manifa–Tanajib Bay System of Saudi Arabia based on a once-off sampling event
2011
Joydas, T.V. | Krishnakumar, P.K. | Qurban, Mohammad A. | Ali, Said M. | Al-Suwailem, Abdulaziz | Al-Abdulkader, Khaled
Shallow water bays located in the western Arabian Gulf experience harsh environmental conditions. Some of these bays, including Manifa–Tanajib Bay System (MTBS), were also exposed to the 1991 oil pollution event. This study investigates the status of the macrobenthos in MTBS during 2006. This bay system is characterized by very shallow inner bays with elevated salinity and temperature compared to the rest of the bay area. As a result mainly of the hyper salinity, the inner bay communities are distinct from the outer bay communities. Overall, fairly high species richness with several rare species was observed. High Shannon–Wiener diversity values and ABC plots indicated the healthy status of the polychaete communities, while BOPA index indicated slightly polluted status in 20% of the stations. The oil sensitive amphipods were not completely re-colonized in 20% of the stations, even after 15years of recovery from the 1991 oil spill.
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