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Experimental assessment of critical anthropogenic sediment burial in eelgrass Zostera marina Texte intégral
2015
Munkes, Britta | Schubert, Philipp R. | Karez, Rolf | Reusch, Thorsten B.H.
Experimental assessment of critical anthropogenic sediment burial in eelgrass Zostera marina Texte intégral
2015
Munkes, Britta | Schubert, Philipp R. | Karez, Rolf | Reusch, Thorsten B.H.
Seagrass meadows, one of the world's most important and productive coastal habitats, are threatened by a range of anthropogenic actions. Burial of seagrass plants due to coastal activities is one important anthropogenic pressure leading to the decline of local populations. In our study, we assessed the response of eelgrass Zostera marina to sediment burial from physiological, morphological, and population parameters. In a full factorial field experiment, burial level (5–20cm) and burial duration (4–16weeks) were manipulated. Negative effects were visible even at the lowest burial level (5cm) and shortest duration (4weeks), with increasing effects over time and burial level. Buried seagrasses showed higher shoot mortality, delayed growth and flowering and lower carbohydrate storage. The observed effects will likely have an impact on next year's survival of buried plants. Our results have implications for the management of this important coastal plant.
Afficher plus [+] Moins [-]Experimental assessment of sediment burial in eelgrass Zostera marina in Kiel Bight Texte intégral
2015
Munkes, Britta | Schubert, Philipp | Karez, Rolf | Reusch, Thorsten B H
Seagrass meadows, one of the world's most important and productive coastal habitats, are threatened by a range of anthropogenic actions. Burial of seagrass plants due to coastal activities is one important anthropogenic pressure leading to the decline of local populations. In our study, we assessed the response of eelgrass Zostera marina to sediment burial from physiological, morphological, and population parameters. In a full factorial field experiment, burial level (5-20cm) and burial duration (4-16 weeks) were manipulated. Negative effects were visible even at the lowest burial level (5 cm) and shortest duration (4 weeks), with increasing effects over time and burial level. Buried seagrasses showed higher shoot mortality, delayed growth and flowering and lower carbohydrate storage. The observed effects will likely have an impact on next year's survival of buried plants. Our results have implications for the management of this important coastal plant.
Afficher plus [+] Moins [-]Integrating science education and marine conservation through collaborative partnerships Texte intégral
2015
Martin, Jeannie Miller | Higgins, Katie | Lee, Kristin | Stearns, Kira | Hunt, Lori
The Georgia Sea Turtle Center has a mission of conservation based rehabilitation, research, and education. Marine debris is a serious threat to marine species. In an effort to educate local students, the GSTC obtained a grant to provide educational opportunities to local third graders. Third and fourth grade classes in Glynn County, Georgia were offered a Garbage in the Water program and 964 students were reached. After programming, students showed a statistically significant (p<.0001) increase in test scores between the pre and posttests. This success led to repeat funding for additional programming for first grades as well as a formalized relationship with the Glynn County School District. As part of this relationship the Georgia Sea Turtle Center is now the official field trip location for all third grades in the district.
Afficher plus [+] Moins [-]Variation in bioaccumulation of persistent organic pollutants based on octanol–air partitioning: Influence of respiratory elimination in marine species Texte intégral
2015
Moses, Sara K. | Harley, John R. | Lieske, Camilla L. | Muir, Derek C.G. | Whiting, Alex V. | O'Hara, Todd M.
Risk assessments of persistent organic pollutants (POPs) are often based on octanol–water (KOW) partitioning dynamics and may not adequately reflect bioaccumulation in air-breathing organisms. It has been suggested that compounds with low KOW and high octanol–air partitioning (KOA) coefficients have the potential to bioaccumulate in air-breathing organisms, including marine mammals. Here we evaluate differences in concentrations of POPs for two trophically matched Arctic species, spotted seal (Phoca largha) and sheefish (Stenodus leucichthys). We compared concentrations of 108 POPs in matched tissues (liver and muscle) across three ranges of KOW. We found a significant positive correlation between POP concentration and log KOA in spotted seal tissues for low log KOW compounds (log KOW <5.5, p<0.05). This provides further evidence for empirical models and observed bioaccumulation patterns in air-breathing organisms, and highlights the potential for bioaccumulation of these compounds in Arctic marine mammals.
Afficher plus [+] Moins [-]Trace elements distribution in hawksbill turtle (Eretmochelys imbricata) and green turtle (Chelonia mydas) tissues on the northern coast of Bahia, Brazil Texte intégral
2015
de Macêdo, Gustavo R. | B. Tarantino, Taiana | Barbosa, Isa S. | Pires, Thaís T. | Rostan, Gonzalo | Goldberg, Daphne W. | Pinto, Luis Fernando B. | Korn, Maria Graças A. | Franke, Carlos Roberto
Concentrations of elements (As, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn) were determined in liver, kidneys and bones of Eretmochelys imbricata and Chelonia mydas specimens found stranded along the northern coast of Bahia, Brazil. Results showed that the concentrations of Cd, Cu, Ni and Zn in the liver and kidneys of juvenile C. mydas were the highest found in Brazil. We also observed a significant difference (p<0.05) on the bioaccumulation of trace elements between the two species: Al, Co, Mo, Na and Se in the liver; Al, Cr, Cu, K, Mo, Ni, Pb, Sr and V in the kidneys; and Al, Ba, Ca, Cd, Mn, Ni, Pb, Se, Sr and V in the bones. This study represents the first report on the distribution and concentration of trace elements in E. imbricata in the Brazilian coast.
Afficher plus [+] Moins [-]Depositional record of trace metals and degree of contamination in core sediments from the Mandovi estuarine mangrove ecosystem, west coast of India Texte intégral
2015
Veerasingam, S. | Vethamony, P. | Mani Murali, R. | Fernandes, B.
The concentrations of seven trace metals (Fe, Mn, Cu, Cr, Co, Pb and Zn) in three sediment cores were analysed to assess the depositional trends of metals and their contamination level in the Mandovi estuary, west coast of India. All sediment cores showed enrichment of trace metals in the upper part of core sediments and decrease in concentration with depth, suggesting excess of anthropogenic loading (including mining activities) occurred during the recent past. Scanning electron microscope (SEM) images distinguished the shape, size and structure of particles derived from lithogenic and anthropogenic sources in core sediments. The geo-accumulation index (Igeo) values indicate that Mandovi estuary is ‘moderately polluted’ with Pb, whereas ‘unpolluted to moderately polluted’ with Fe, Mn, Cu, Cr, Co and Zn. The comparative analysis of trace metals revealed that Fe and Mn were highly enriched in the Mandovi estuary compared to all other Indian estuaries.
Afficher plus [+] Moins [-]Intersex in the clam Scrobicularia plana (Da Costa): Widespread occurrence in English Channel estuaries and surrounding areas Texte intégral
2015
Pope, N.D. | Childs, K. | Dang, C. | Davey, M.S. | O’Hara, S.C.M. | Langston, K. | Minier, C. | Pascoe, P.L. | Shortridge, E. | Langston, W.J.
Estuarine clams Scrobicularia plana were sampled from 108 intertidal locations around the English Channel and adjacent areas. Although S. plana is believed to be a strict gonochorist, 58% of the populations sampled included intersexed individuals (described as male clams exhibiting ovotestis). Over the entire region, on average, 8.6% of male clams exhibited intersex, although proportions of affected males ranged from 0% to 53% depending on location. The severity of intersex was assessed using a simple classification scale, with the majority of individuals showing low levels of impact. Sex ratios were significantly skewed at some sites. There were no significant relationships between incidence or severity of intersex; or with size or parasitism of individual clams. Intersex in S. plana is a useful tool to assess endocrine disruptive effects in estuaries, although mechanisms of impact and causative agents remain uncertain.
Afficher plus [+] Moins [-]Polycyclic aromatic hydrocarbons, polychlorinated biphenyls and organochlorine pesticides in European hake (Merluccius merluccius) muscle from the Western Mediterranean Sea Texte intégral
2015
Moraleda-Cibrián, Núria | Carrassón, Maite | Rosell-Melé, A. (Antoni)
Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were quantified in muscle tissue of European hake, an ecologically and commercially important species. Samples were collected from the Western Mediterranean, in seven different stations at different depths and a batch was bought in a local market. PCBs are the dominant pollutants, but the overall concentrations do not show significant differences between the different specimens analyzed from various locations, with the exception of the concentration of PCBs at a shallow station close to the River Besòs mouth. This probably suggests that generally the pollutants in hake from the Western Mediterranean derive from historical and non-point sources. The occurrence of pollutants is widespread in the samples but their concentration is below recommended legal limits for fish or other foodstuffs.
Afficher plus [+] Moins [-]Debris ingestion by juvenile marine turtles: An underestimated problem Texte intégral
2015
Santos, Robson Guimarães | Andrades, Ryan | Boldrini, Marcillo Altoé | Martins, Agnaldo Silva
Marine turtles are an iconic group of endangered animals threatened by debris ingestion. However, key aspects related to debris ingestion are still poorly known, including its effects on mortality and the original use of the ingested debris. Therefore, we analysed the impact of debris ingestion in 265 green turtles (Chelonia mydas) over a large geographical area and different habitats along the Brazilian coast. We determined the death rate due to debris ingestion and quantified the amount of debris that is sufficient to cause the death of juvenile green turtles. Additionally, we investigated the original use of the ingested debris. We found that a surprisingly small amount of debris was sufficient to block the digestive tract and cause death. We suggested that debris ingestion has a high death potential that may be masked by other causes of death. An expressive part of the ingested debris come from disposable and short-lived products.
Afficher plus [+] Moins [-]Natural dispersion revisited Texte intégral
2015
Johansen, Øistein | Reed, Mark | Bodsberg, Nils Rune
This paper presents a new semi-empirical model for oil droplet size distributions generated by single breaking wave events. Empirical data was obtained from laboratory experiments with different crude oils at different stages of weathering. The paper starts with a review of the most commonly used model for natural dispersion, which is followed by a presentation of the laboratory study on oil droplet size distributions formed by breaking waves conducted by SINTEF on behalf of the NOAA/UNH Coastal Response Research Center. The next section presents the theoretical and empirical foundation for the new model. The model is based on dimensional analysis and contains two non-dimensional groups; the Weber and Reynolds number. The model was validated with data from a full scale experimental oil spill conducted in the Haltenbanken area offshore Norway in July 1982, as described in the last section of the paper.
Afficher plus [+] Moins [-]Enterococcus species diversity and molecular characterization of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands, India Texte intégral
2015
Meena, Balakrishnan | Anburajan, Lawrance | Sathish, Thadikamala | Raghavan, Rangamaran Vijaya | Jha, Dilip Kumar | Venkateshwaran, Pitchiah | Das, Apurba Kumar | Dheenan, Palaiya Sukumaran | Vinithkumar, Nambali Valsalan | Dharani, Gopal | Kirubagaran, Ramalingam
This study was performed to evaluate the abundance and diversity of Enterococcus sp. and the distribution of biomarker genes in Enterococcus faecalis in Port Blair Bay, Andaman and Nicobar Islands. The Enterococcus sp. densities at the seven sampling stations were highly influenced by tidal fluctuations and season. The distributions and diversities of species varied in the inner and outer regions of Port Blair Bay. Among the 1816 total isolates, the occurrence of fecal Enterococcus was high (1.78×104CFU/100mL) in Phoenix Bay. Moreover, 67.76% of the isolates were identified as Enterococcus, and the most frequently identified species were E. hirae, E. avium and E. faecalis. Assessments of antibiotic resistance and biomarker genes revealed the maximum occurrence in the Aberdeen Bay isolates. The most prevalent biomarker genes observed in the E. faecalis isolates were gelE and asa1, whereas cyl was not found among the isolates. In silico sequence analysis of biomarker genes of E. faecalis also revealed that they are evolutionarily well conserved with those of earlier reports. Further, multivariate analysis distinguished the JB, PB and OS stations from the other stations according to distinctive microbial densities and compositions. In addition, the Shannon-Wiener diversity indices and box-whisker plots further facilitated and supported the multivariate results.
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