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Concentration of organic sun-blocking agents in seawater of beaches and coral reefs of Okinawa Island, Japan Texto completo
2013
Tashiro, Yutaka | Kameda, Yutaka
The concentration of UV filters (UVFs) and UV light stabilizers (UVLSs) were measured in seawater and river water collected from sites at four beaches, two reefs, and one river on Okinawa Island, Japan. UVFs and/or UVLSs of 8–10 types were detected in beaches samples and 6–9 types were detected in reef samples. The total UVF concentrations at the beach sites were highest either in July or August with a maximum of 1.4μgL−1. The concentrations at the reef sites did not show peaks in summer and the maximum values were close to 10ngL−1. The detected UVF profiles reflected the ingredients of sunscreens used in each region. The highest UVLS concentrations at the reefs were observed not only in summer but also in June and September. The UVLS concentrations at the reefs were similar to or even higher than that at the beaches or in the river.
Mostrar más [+] Menos [-]Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) Texto completo
2013
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D’Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses | Pardal, Miguel Ângelo
Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) Texto completo
2013
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D’Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses | Pardal, Miguel Ângelo
The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities’ structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
Mostrar más [+] Menos [-]Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal)
Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal) Texto completo
2013 | 1000
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D'Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses Miranda | Pardal, Miguel Ângelo
The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities' structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
Mostrar más [+] Menos [-]Natural antifouling compounds produced by a novel fungus Aureobasidium pullulans HN isolated from marine biofilm Texto completo
2013
Gao, Min | Su, Rongguo | Wang, Ke | Li, Xuzhao | Lu, Wei
A fungus, Aureobasidium pullulans, was isolated from marine biofilm and identified. A bioassay-guided fractionation procedure was developed to isolate and purify antifouling compounds from A. pullulans HN. The procedure was: fermentation broth—aeration and addition of sodium thiosulfate–graduated pH and liquid–liquid extraction—SPE purification—GC–MS analysis. Firstly, the fermentation broth was tested for its toxicity. Then it was treated with aeration and addition of sodium thiosulfate, and its toxicity was almost not changed. Lastly, antifouling compounds were extracted at different pH, the extract had high toxicity at pH 2 but almost no toxicity at pH 10, which suggested the toxicants should be fatty acids. The EC50 of the extract against Skeletonema costatum was 90.9μgml−1, and its LC50 against Balanus amphitrete larvae was 22.2μgml−1. After purified by HLB SPE column, the EC50 of the extract against S. costatum was 49.4μgml−1. The myristic and palmitic acids were found as the main toxicants by GC–MS.
Mostrar más [+] Menos [-]Silicon alleviates cadmium toxicity in Avicennia marina (Forsk.) Vierh. seedlings in relation to root anatomy and radial oxygen loss Texto completo
2013
Zhang, Qiong | Yan, Chongling | Liu, Jingchun | Lu, Haoliang | Wang, Wenyun | Du, Jingna | Duan, Hanhui
The effects of Si on growth, the anatomy of the roots, radial oxygen loss (ROL) and Fe/Mn plaque on the root surface were investigated in Avicennia marina (Forsk.) Vierh. seedlings under Cd stress. Si prompted the growth of seedlings and reduced the Cd concentration in the root, stem and leaf of A. marina. Si prompted the development of the apoplastic barrier in the roots, which may be related to the reduction of Cd uptake. The higher amount of ROL and Mn plaque on the root surface due to Si were also related to the promotion of Cd tolerance in A. marina seedlings. Therefore, it is concluded that the alteration of the anatomy of the roots, the increase of ROL and Mn plaque of A. marina seedlings play an important role in alleviation of Cd toxicity due to Si.
Mostrar más [+] Menos [-]Trophic calculations reveal the mechanism of population-level variation in mercury concentrations between marine ecosystems: Case studies of two polar seabirds Texto completo
2013
Brasso, Rebecka L. | Polito, Michael J.
The incorporation of quantitative trophic level analysis in ecotoxicological studies provides explanatory power to identify the factors, trophic or environmental, driving population-level variation in mercury exposure at large geographic scales. In the Antarctic marine ecosystem, mercury concentrations and stable isotope values in Adélie penguins (Pygoscelis adeliae) were compared between the Antarctic Peninsula and the Ross Sea. Correcting tissue δ15N values for baseline δ15N values revealed population-level differences in trophic position which contributes to differences in mercury. Data from Thick-billed murres (Uria lomvia) were synthesized from published values from Baffin Bay and Svalbard to demonstrate the utility of baseline δ15N values in identifying differences in environmental mercury exposure independent of diet. Here, we demonstrate the importance of calculating population-specific trophic level data to uncover the source of variation in mercury concentrations between geographically distinct populations of marine predators.
Mostrar más [+] Menos [-]Molecular detection of atrazine catabolism gene atzA in coastal waters of Georgia, Puerto Rico and Trinidad Texto completo
2013
Sherchan, Samendra P. | Bachoon, D.S. | Otero, Ernesto | Ramsubhag, Adesh
In this study, quantitative polymerase chain reaction targeting the atrazine catabolism gene, atzA, was used to detect the presence of atrazine degrading bacteria as an indicator of atrazine contamination in 11 sites in Georgia, nine coastal sites in Puerto Rico and 11 coastal sites in Trinidad. The atzA gene was detected in five stations in Georgia (Oak Grove Island entrance, Blythe Island Recreation Park, Jekyll Island., Village Creek Landing and Dunbar Creek Sea Island Rd Bridge). In Puerto Rico gene was detected in five sites (Boquilla, Oro Creek, Fishers Association, Ceiba Creek and Sabalos Creek) while seven sites in Trinidad (Carli Bay, Las Cuevas Bay, Quinam Bay, Salybia River, Salybia Bay, Maracas River and Maracas Bay) showed the presence of atzA.
Mostrar más [+] Menos [-]Combined SEM/AVS and attenuation of concentration models for the assessment of bioavailability and mobility of metals in sediments of Sepetiba Bay (SE Brazil) Texto completo
2013
Ribeiro, Andreza Portella | Figueiredo, Ana Maria Graciano | Santos, José Osman dos | Dantas, Elizabeth | Cotrim, Marycel Elena Barboza | Cesar Lopes Figueira, Rubens | V. Silva Filho, Emmanoel | Cesar Wasserman, Julio
This study proposes a new methodology to study contamination, bioavailability and mobility of metals (Cd, Cu, Ni, Pb, and Zn) using chemical and geostatistics approaches in marine sediments of Sepetiba Bay (SE Brazil). The chemical model of SEM (simultaneously extracted metals)/AVS (acid volatile sulfides) ratio uses a technique of cold acid extraction of metals to evaluate their bioavailability, and the geostatistical model of attenuation of concentrations estimates the mobility of metals. By coupling the two it was observed that Sepetiba Port, the urban area of Sepetiba and the riverine discharges may constitute potential sources of metals to Sepetiba Bay. The metals are concentrated in the NE area of the bay, where they tend to have their lowest mobility, as shown by the attenuation model, and are not bioavailable, as they tend to associate with sulfide and organic matter originated in the mangrove forests of nearby Guaratiba area.
Mostrar más [+] Menos [-]Microscopic observation of symbiotic and aposymbiotic juvenile corals in nutrient-enriched seawater Texto completo
2013
Tanaka, Yasuaki | Iguchi, Akira | Inoue, Mayuri | Mori, Chiharu | Sakai, Keinan | Suzuki, Atsushi | Kawahata, Hodaka | Nakamura, Takashi
Symbiotic and aposymbiotic juvenile corals, which were grown in the laboratory from the gametes of the scleractinian coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic corals were in close physical contact with BMA. The areal growth rate of the symbiotic corals was significantly higher than that of the aposymbiotic corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic coral polyps and enhanced the growth of some of the symbiotic corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile corals to survive in high-nutrient seawater.
Mostrar más [+] Menos [-]Biomonitoring of 2,4’–methylene diphenyldianiline for assessment of exposure to methylene diphenyl diisocyanate aerosol Texto completo
2013
Mirmohammadi, Seyedtaghi | Najafpour, Ghasem | Ahmad, Anees | Hakimi, Ibrahim
The exposure to methylene diphenyl diisocyanate (MDI) aerosol was investigated by biomnitoring of 2,4’–methylene diphenyldianiline (MDA) in urines of exposed workers. Biological monitoring was done for its metabolite by the analysis of isocyanate–derived diamines released from protein adducts in urine or plasma by GC–MS. The urine samples, at the end of working shifts of polyurethane factory, were collected in polystyrene bottles containing 10 g citric acid, and stored at 4 °C until analysis. The mean concentration values of MDA in the five selected factories were in the range of 3.01 to 3.58 µmol/mol creatinine for all subjects and the highest mean value of MDI concentration was 99 µg/m³ from indoor air samples analysis. The results show a linear relationship between MDI and MDA concentrations with a value of R2=0.801 (P<0.05). This study demonstrates that not only urinary MDA is detectable following diisocyanates aerosol exposure but also it is likely to be a useful practical biomarker to monitor diisocyanates exposure in the workplaces or for the epidemiologic studies.
Mostrar más [+] Menos [-]Gull-derived trace elements trigger small-scale contamination in a remote Mediterranean nature reserve Texto completo
2013
Signa, Geraldina | Mazzola, Antonio | Tramati, Cecilia Doriana | Vizzini, Salvatrice
The role of a yellow-legged gull (Larus michahellis) small colony in conveying trace elements (As, Cd, Cr, Cu, Ni, Pb, THg, V, Zn) was assessed in a Mediterranean nature reserve (Marinello ponds) at various spatial and temporal scales. Trace element concentrations in guano were high and seasonally variable. In contrast, contamination in the ponds was not influenced by season but showed strong spatial variability among ponds, according to the different guano input. Biogenic enrichment factor B confirmed the role of gulls in the release of trace elements through guano subsidies. In addition, comparing trace element pond concentrations to the US NOAA’s SQGs, As, Cu and Ni showed contamination levels associated with possible negative biological effects. Thus, this study reflects the need to take seabirds into account as key factors influencing ecological processes and contamination levels even in remote areas, especially around the Mediterranean, where these birds are abundant but overlooked.
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