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Relationship between wind and seagrass meadows in a non-tidal eutrophic lagoon studied by a Wave Exposure Model (WEMo)
2013
Rubegni, Fabrizio | Franchi, Enrica | Lenzi, Mauro
The hydrodynamic action of wind and the distribution of biomass of seagrass meadows in a non-tidal eutrophic lagoon (Orbetello Lagoon, Tuscany, Italy) were analysed for correlations by simulation with a Wave Exposure Model (WEMo) on 5-year data series. WEMo and statistical analysis established a weak direct correlation between the areas that the model identified as being subject to resuspension and transport of sediment and those actually colonised by seagrass. A significant difference was found between surface and bottom hydrodynamics. The areas that the model identified as exposed to higher energy surface hydrodynamics proved to be inversely correlated with seagrass biomass. Multivariate statistical analysis ordered the model variables according to their relative importance. The model indicated the need for further study, demonstrating its utility for environmental management of eutrophic lagoons.
Afficher plus [+] Moins [-]Initial impacts of the Hebei Spirit oil spill on the sandy beach macrobenthic community west coast of Korea
2013
Yu, Ok Hwan | Lee, Hyung-Gon | Shim, Won Joon | Kim, Moonkoo | Park, Heung-Sik
Petroleum hydrocarbon contamination and macrobenthos in the sandy tidal flats of Taean were monitored for 1year to assess the impacts of Hebei Spirit oil on the macrobenthic community. A total of 207 macrobenthic fauna was collected, and the mean density and biomass of macrobenthic fauna continued to decrease until 12months after the oil spill, but macrobenthic density at the most heavily affected sites increased by about twofold. In January 2008, the dominant species occurred at very low densities in strongly affected sites. The macrobenthic communities differed between oil-affected and unaffected sites. In particular, differences in community structure at Mallipo beach were larger than those at Shinduri. We suggest that long-term monitoring is needed to assess the specific effects of oil pollution on the sandy intertidal macrobenthic community.
Afficher plus [+] Moins [-]Perfluorinated compounds in blood of Caretta caretta from the Mediterranean Sea
2013
Guerranti, Cristiana | Ancora, Stefania | Bianchi, Nicola | Perra, Guido | Fanello, Emiliano Leonida | Corsolini, Simonetta | Fossi, Maria Cristina | Focardi, Silvano Ettore
Perfluorinated compounds (PFCs), widely used for their hydro-oil repellent properties, are almost non-degradable in the environment; there is scientific evidence that indicate bioaccumulation. They represent a threat to many organisms, because they are toxic and are endocrine disruptors. Scientific studies have demonstrated the presence of PFCs in blood and liver samples of fish, turtles, birds and mammals of marine ecosystems in different geographical areas. The aim of this study was to determine the distribution of PFOS and PFOA in blood samples of the marine turtle Caretta caretta, using a minimally invasive sampling procedure. 49 blood samples of marine turtle, taken from several Italian marine turtle rescue centers, were analyzed. While PFOA was never detected, measurable concentrations of PFOS were found in 15 blood samples; the values show a range from 1.14ng/g to 28.51ng/g (wet wt.). No differences between groups of samples taken from different areas were found.
Afficher plus [+] Moins [-]Carbon and nitrogen stable isotope ratios and mercury concentration in the scalp hair of residents from Taiji, a whaling town
2013
Endo, Tetsuya | Hayasaka, Moriaki | Hisamichi, Yohsuke | Kimura, Osamu | Haraguchi, Koichi
We analyzed stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) as well as mercury (Hg) concentration in the scalp hair of Japanese who consumed whale meat and those who did not, and investigated the relationships among the δ13C and δ15N values and Hg concentration. The average δ15N and δ13C values of whale meat-eaters (10.11‰ and −18.5‰) were significantly higher than those of non-eaters (9.28‰ and −18.9‰), respectively. The average Hg concentration of whale meat-eaters (20.6μg/g) was significantly higher than that of non-eaters (2.20μg/g). Significant positive correlations were found between the δ13C and δ15N values and between the δ15N value and Hg concentration in the hair of whale meat-eaters, while the correlation between the δ15N value and Hg concentration was not statistically significant in the non-eaters. The consumption of whale meat may increase Hg concentration as well as δ15N and δ13C values in scalp hair.
Afficher plus [+] Moins [-]Drivers of estuarine benthic species distribution patterns following a restoration of a seagrass bed: A functional trait analyses
2013
Dolbeth, Marina | Cardoso, Patricia | Grilo, Tiago | Raffaelli, Dave | Pardal, Miguel Ângelo
We integrate information on functional diversity (FD) patterns from estuarine intertidal benthic communities from different habitats and along a temporal disturbance gradient, to understand the drivers of species coexistence patterns. Species and traits’ biomass levels seemed to be first determined by habitat filtering, selecting those traits better adapted to the biologically challenging estuarine environment. Within that subset of traits and within each habitat, biotic interactions were probably high, as evidenced by high α-diversity and community weighted mean differences. The former patterns hold for the disturbance/recovery scenario considered. However, as the estuary recovered, biomass became more distributed among different trait categories, consistent with increases in FD when the seagrass started to increase. Policy towards the restoration of seagrass bed and other biogenic structures, and improving the connectivity within adjacent systems were confirmed and suggested, as this would imply higher FD and potentially higher resilience to disturbance within the estuarine intertidal system.
Afficher plus [+] Moins [-]Incidence of plastic fragments among burrow-nesting seabird colonies on offshore islands in northern New Zealand
2013
Buxton, Rachel T. | Currey, Caitlin A. | Lyver, Philip O’B. | Jones, Christopher J.
Marine plastic pollution is ubiquitous throughout the world’s oceans, and has been found in high concentrations in oceanic gyres of both the northern and southern hemispheres. The number of studies demonstrating plastic debris at seabird colonies and plastic ingestion by adult seabirds has increased over the past few decades. Despite the recent discovery of a large aggregation of plastic debris in the South Pacific subtropical gyre, the incidence of plastics at seabird colonies in New Zealand is unknown. Between 2011 and 2012 we surveyed six offshore islands on the northeast coast of New Zealand’s North Island for burrow-nesting seabird colonies and the presence of plastic fragments. We found non-research related plastic fragments (0.031pieces/m2) on one island only, Ohinau, within dense flesh-footed shearwater (Puffinus carneipes) colonies. On Ohinau, we found a linear relationship between burrow density and plastic density, with 3.5 times more breeding burrows in areas with plastic fragments found. From these data we conclude that plastic ingestion is a potentially a serious issue for flesh-footed shearwaters in New Zealand. Although these results do not rule out plastic ingestion by other species, they suggest the need for further research on the relationship between New Zealand’s pelagic seabirds and marine plastic pollution.
Afficher plus [+] Moins [-]Echinoderms from Azores islands: An unexpected source of antibiotic resistant Enterococcus spp. and Escherichia coli isolates
2013
Marinho, Catarina | Silva, Nuno | Pombo, Sofia | Santos, Tiago | Monteiro, Ricardo | Gonçalves, Alexandre | Micael, Joana | Rodrigues, Pedro | Costa, Ana Cristina | Igrejas, Gilberto | Poeta, Patrícia
The prevalence of antibiotic resistance and the implicated mechanisms of resistance were evaluated in Enterococcus spp. and Escherichia coli, isolated from a total of 250 faecal samples of echinoderms collected from Azorean waters (Portugal). A total of 144 enterococci (120 Enterococcus faecium, 14 E. hirae, 8 E. faecalis, 2 E. gallinarum) and 10 E. coli were recovered. High percentages of resistance in enterococci were found for erythromycin, ampicillin, tetracyclin and ciprofloxacin. The erm(A) or erm(B), tet(M) and/or tet(L), vat(D), aac(6′)-aph(2″) and aph(3′)-IIIa genes were found in isolates resistant to erythromycin, tetracycline, quinupristin/dalfopristin, high-level gentamicin and high-level kanamycin, respectively. Resistance in E. coli isolates was detected for streptomycin, amikacin, tetracycline and tobramycin. The aadA gene was found in streptomycin-resistant isolates and tet(A)+tet(B) genes in tetracycline-resistant isolates. The data recovered are essential to improve knowledge about the dissemination of resistant strains through marine ecosystems and the possible implications involved in transferring these resistances either to other animals or to humans.
Afficher plus [+] Moins [-]Seasonal variation of metal contamination in the barnacles Pollicipes pollicipes in northwest coast of Portugal show clear correlation with levels in the surrounding water
2013
Reis, Pedro A. | Salgado, María Antonia | Vasconcelos, Vitor
The concentrations of metals were determined in northwest (NW) coast of Portugal seawaters and soft tissues of goose barnacles Pollicipes pollicipes. P. pollicipes can be used for monitoring metal contamination in these coastal seawaters, because there were significant correlations (p<0.05) for all metals between soft tissues and seawaters during the four seasons. Metal concentrations in seawaters and P. pollicipes had significant (p<0.05) spatial and seasonal variations and mean log BAFs for Fe and Cd were higher than for Cr, Cu, Mn and Zn. Regarding the metal concentrations obtained in the coastal seawaters, all NW coast of Portugal should be classified as “Class IV – Bad”, except two locations (location 7 at Summer and location 10 at Winter), which should be classified as “Class III – Moderate”. However, considering the metal concentrations bioaccumulated in P. pollicipes, all locations should be classified as “Class III – Remarkably Polluted” during all seasons of 2011.
Afficher plus [+] Moins [-]Artificial radionuclides 90Sr and 241Am in the sediments of the Baltic Sea: Total and spatial inventories and some temporal trends
2013
Hutri, Kaisa-Leena | Mattila, Jukka | Ikäheimonen, Tarja Tuulikki | Vartti, Vesa-Pekka
The Baltic Sea was contaminated by radioactivity following global nuclear fallout and later by the Chernobyl accident. Despite the decrease of radioactivity caused by radioactive decay, radionuclides have a prolonged residence time in the water of the Baltic Sea due to slow water exchange and relatively rapid sedimentation. Very little is known about the amounts or spatial differences of 90Sr and 241Am in the Baltic Sea sediments. In this study, 20 sediment cores taken around the Baltic Sea were investigated to estimate inventories of these radionuclides. The rough results show that the Chernobyl fallout added the amount of 90Sr in the same areas where the increase of 137Cs can be detected, whereas this is not the case for 241Am which is more evenly distributed in the sea bottom. In addition, local differences occur in the concentrations. These results are an important amendment to the radioactivity baseline of the Baltic Sea.
Afficher plus [+] Moins [-]Characterization of mercury in atmospheric particulate matter in the southeast coastal cities of China
2013
Xu, Lingling | Chen, Jinsheng | Niu, Zhenchuan | Yin, Liqian | Chen, Yanting
Although present in a low concentration in the atmosphere, mercury in particulate matter (PHg) plays an important role in the biogeochemical process of mercury. In this study, the mercury concentrations in three size fractions of airborne particulate matters collected from 14 sites (12 urban sites, 1 rural site and 1 remote site) in the southeast coastal cities of China during different seasons in 2010–2011 were investigated. Most of PHg (46.8–71.9%) was concentrated in the finer particles, i.e. PM2.5 (particulate matter ≤2.5 µm in aerodynamic diameter). The average mercury concentrations in PM2.5 were 141.2±128.1 (range of 7.6–956.5), 37.0±19.2 (5.6–89.4), and 24.0±14.6 (3.2– 59.9) pg m–3 at urban, rural, and remote sites during the whole sampling period, respectively. The PHg concentrations were almost at the same level in spring, autumn, and winter, approximately two times of that in summer. PHg concentrations in the atmosphere displayed a significant spatial variation with far higher values in urban areas than those at rural and remote sites. The dry deposition fluxes of total PHg estimated by a theoretical model were 38.3, 47.7, and 58.7 µg m–2 y–1 at Ji’an (JA), Jimei (JM), and Longwen (LW), respectively. The backward air trajectory analysis revealed that the atmospheric PHg concentrations were mainly influenced by air masses from ocean sources that diluted PHg in summer and on contrary from continental sources in other seasons.
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