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Результаты 1751-1760 из 4,926
Detecting the occurrence of indigenous and non-indigenous megafauna through fishermen knowledge: A complementary tool to coastal and port surveys
2019
Azzurro, E. | Bolognini, L. | Dragičević, B. | Drakulović, D. | Dulčić, J. | Fanelli, E. | Grati, F. | Kolitari, J. | Lipej, L. | Magaletti, E. | Marković, O. | Matić-Skoko, S. | Mavrič, B. | Milone, N. | Joksimović, A. | Tomanić, J. | Scarpato, A. | Tutman, P. | Vrdoljak, D. | Zappacosta, F.
Marine bioinvasions and other rapid biodiversity changes require today integrating existing monitoring tools with other complementary detection strategies to provide a more efficient management. Here we explored the efficacy of fishermen observations and traditional port surveys to effectively track the occurrence of both indigenous and non-indigenous megafauna in the Adriatic Sea. This consisted mainly of mobile taxa such as fishes, crustaceans and molluscs. Port surveys using traps and nets within 10 major Adriatic harbours, were compared with the information obtained from 153 interviews with local fishermen. Information gathered by traps and nets varied significantly and generally resulted of limited efficacy in exotic species detection. Interviews allowed tracking the occurrence of new species through time and space, providing complementary knowledge at the low cost. This combined approach improves our capability of being informed on the arrival of species of different origin, providing a more rational, improved basis for environmental management and decision making.
Показать больше [+] Меньше [-]Labile and stable mercury in Harris mud crab (Rhithropanopeus harrisii) from the southern Baltic Sea – Considerations for a role of non-native species in the food web
2019
Wilman, Bartłomiej | Bełdowska, Magdalena | Normant-Saremba, Monika
Mercury is a potent neurotoxin. Its main source of entry into the human body is the consumption of fish and seafood. Within the past few decades a new species of crab has appeared in the food web of the southern Baltic: Rhithropanopeus harrisii. The aim of the present study was to estimate the level of total and labile mercury concentrations in this species collected from the southern Baltic Sea. Analyses were performed using the thermodesorption method. The share of organic mercury fraction, as well as the Hgtot, increased with the size class of the crabs. Due to the increasingly common occurrence of R. harrisii and the low HgTOT concentration in its body, and assuming that it is bound to become a more and more common component of the diet of fish, it can be supposed that the load of toxic mercury entering the food web is likely to decrease.
Показать больше [+] Меньше [-]Contribution of fluorite mining waste to mercury contamination in coastal systems
2019
Forján, Rubén | Baragaño, Diego | Boente, Carlos | Fernández-Iglesias, Elena | Rodríguez-Valdes, Eduardo | Gallego, J.R.
Samples from 13 beaches along the northern Spanish coast, a region with a history of heavy industries, were first screened to identify signs of pollution. High concentrations of Hg and Ba on Vega beach were found, both elements belong to the fluorite ore paragenesis, mined in the surroundings. Samples of beach and fluvial sediments, and nearby soils were collected in Vega beach area to address potential Hg pollution, fate and sources. Most samples showed a similar pollutants fingerprint to that of beach samples, especially those taken from white dunes, registering notable Hg concentrations. Hg was enriched in the finer fractions, and overall the main input was attributed to the mining waste discharged along the coast in the past. Although a specific risk assessment and study of the submerged sediments are advisable for this area, Hg bioavailability and methylation were low, thus indicating that this metal poses a reduced environmental risk.
Показать больше [+] Меньше [-]Assessment of the organotin pollution in the coastal sediments of the Western Arabian Gulf, Saudi Arabia
2019
Hassan, Akere Taiwo | Qurban, Mohammed | Manikandan, Karuppasamy | Tawabini, Bassam | Basheer, Chanbasha | Periyadan, Krishnakumar
Organotin compounds (OTCs) are persistent pollutants and are considered as chemicals of environmental concern. They enter the marine environment from the antifouling paints containing organotin compounds on the hulls of ships and boats. We report the results of a study conducted in 2015 on the level of butyltins (TBT, DBT, and MBT) and phenyltins (TPhT, DPhT, and MPhT) in the sediments collected from three fishing harbors (Jubail, Khobar, and Qatif) and a reference site (Half Moon Bay). The concentrations of OTCs in the sediments vary widely among the different sampling locations. Overall, the phenyltins contribute more than the butyltins and the order of the abundance is: MPhT > DPhT > MBT > DBT > TPhT. In most stations, the concentrations of MBT are higher than DBT. The sediments from Khobar and Qatif are moderately polluted, whereas those from the Jubail are ranked as highly polluted. The concentrations of TBT at all study sites are less than the detection limit, and hence, the environmental and ecotoxicological risks are low.
Показать больше [+] Меньше [-]Marine litter in the Croatian part of the middle Adriatic Sea: Simultaneous assessment of floating and seabed macro and micro litter abundance and composition
2019
Palatinus, Andreja | Kovač Viršek, Manca | Robič, Uroš | Grego, Mateja | Bajt, Oliver | Šiljić, Jasna | Suaria, Giuseppe | Liubartseva, Svitlana | Coppini, Giovanni | Peterlin, Monika
In this study, abundance, distribution and composition of floating and seabed macro and micro litter in the Central Adriatic Sea were assessed. Floating macro litter observations were made. Floating and seabed micro litter were sampled with manta net and Van Veen grab, respectively. Micro litter particles visually found under the microscope were chemically analyzed with Fourier Transform Infrared microscope. Average calculated concentrations of floating macro (175 items/km2), floating micro (127 thousand particles/km2) and seabed micro litter (36 particles/100 g dry weight) show similar values as other published studies from the Mediterranean Sea. A statistically significant (p < 0.01) correlation between the floating micro and macro litter concentrations was found for the sites located in the channel waters. Disagreement between model and observations revealed gaps in our knowledge concerning the sea circulation and litter sources. Simultaneous samplings and observations of marine litter in different marine compartments proved possible, efficient and informative.
Показать больше [+] Меньше [-]Global ecological, social and economic impacts of marine plastic
2019
Beaumont, Nicola J. | Aanesen, Margrethe | Austen, Melanie C. | Börger, Tobias | Clark, James R. | Cole, Matthew | Hooper, Tara | Lindeque, Penelope K. | Pascoe, Christine | Wyles, Kayleigh J.
This research takes a holistic approach to considering the consequences of marine plastic pollution. A semi-systematic literature review of 1191 data points provides the basis to determine the global ecological, social and economic impacts. An ecosystem impact analysis demonstrates that there is global evidence of impact with medium to high frequency on all subjects, with a medium to high degree of irreversibility. A novel translation of these ecological impacts into ecosystem service impacts provides evidence that all ecosystem services are impacted to some extent by the presence of marine plastic, with a reduction in provision predicted for all except one. This reduction in ecosystem service provision is evidenced to have implications for human health and wellbeing, linked particularly to fisheries, heritage and charismatic species, and recreation.
Показать больше [+] Меньше [-]Effects of fish cage culture and suspended oyster culture on macrobenthic communities in Xiangshan Bay, a semi-enclosed subtropical bay in eastern China
2019
Liao, Yibo | Shou, Lu | Jiang, Zhibing | Tang, Yanbin | Du, Ping | Zeng, Jiangning | Chen, Quanzhen | Yan, Xiaojun | Chen, Jianfang
The impacts of fish cage culture and suspended oyster culture on macrobenthic communities were investigated in Xiangshan Bay, China, on a seasonal basis from January to October of 2015. Samples were collected from a fish cage farm, a suspended oyster farm, and two corresponding reference sites. Two-way ANOVA results showed that species richness, abundance, biomass, and Shannon–Wiener diversity differed significantly between the four different investigated areas, and different seasons as well. Cluster analysis showed that macrobenthic community composition in the fish and oyster culture areas significantly differed from that in the reference sites, respectively. Trophic structure of macrobenthos in the fish and oyster culture areas mostly clustered together owing to higher abundance and biomass of surface-deposit feeders and carnivores. The macrobenthic communities and feeding guilds correlated highly with environmental factors, such as bottom water chlorophyll a and nutrients, as well as sediment total organic carbon. Although integrated multi-trophic aquaculture is regarded as a suitable approach to coordinate desirable economic, social, and environmentally sustainable outcomes, coastal ecosystems may suffer from large-scale nutrient enrichment due to aquaculture and other human activities, which should not be considered in isolation.
Показать больше [+] Меньше [-]Differences in Symbiodiniaceae communities and photosynthesis following thermal bleaching of massive corals in the northern part of the South China Sea
2019
Gong, Sanqiang | Xu, Lijia | Yu, Kefu | Zhang, Fengli | Li, Zhiyong
Although many achievements have been made in studies on the relationship between Symbiodiniaceae and coral bleaching, there is little information on the responses of Symbiodiniaceae to coral thermal bleaching in the South China Sea (SCS). In this study, Symbiodiniaceae communities and the effective quantum yield (ФPSII) of healthy and bleached massive corals from the SCS were compared. The results indicated that the Symbiodiniaceae communities and ФPSII values showed coral bleaching-dependent variations. Specifically, the relative abundances of the rare putatively thermally tolerant Durusdinium sp. (D1) and the Symbiochlorum hainanensis increased significantly in the bleached corals. In addition, bleached Porites lutea was mainly associated with the putatively thermally tolerant Cladocopium sp. (C15 and C91) and exhibited the highest ФPSII value compared with other bleached corals. These results highlight that the rare putatively thermally tolerant algae and coral species-specific algae may be important for understanding thermal bleaching of corals.
Показать больше [+] Меньше [-]Effect of black carbon on sorption and desorption of phosphorus onto sediments
2019
Zhang, Hong-Hai | Cao, Xiao-Yan | Wang, He | Ma, Zhun | Li, Jing | Zhou, Li-Min | Yang, Gui-Peng
The sorption behavior of phosphorus onto sediment was investigated with the addition of BC derived from incomplete biomass combustion (PC). The sorption kinetic curves of phosphorus onto PC and sediment could be described by a two-compartment first order equation, and the sorption isotherms fit the Freundlich model well. With increasing amounts of PC added, the sorption capacity increased while the HI did not change much. The distribution of phosphorus forms showed that CaP (ACa-P plus DAP) constituted the highest fraction in the sediment samples. Throughout the sorption process, CaP and OP changed very little, but the Ex-P and FeP increased obviously, and the presence of PC made this increase more significantly. The high specific area and the presence of iron and aluminum, as well as the modification of the sediments surface properties, make the addition of PC be favorable for the sorption of phosphorus onto sediments.
Показать больше [+] Меньше [-]Hexadecane biodegradation of high efficiency by bacterial isolates from Santos Basin sediments
2019
Ferrari, Vitor B. | Cesar, Augusto | Cayô, Rodrigo | Choueri, Rodrigo B. | Okamoto, Débora N. | Freitas, Juliana G. | Favero, Mariana | Gales, Ana C. | Niero, Cristina V. | Saia, Flavia T. | de Vasconcellos, Suzan P.
The aim of the study was the investigation of bacterial diversity from sediments collected at Santos Estuarine System, regarding to their abilities for hexadecane biotransformation. Hexadecane is a medium-chain linear alkane, considered as a model molecule for hydrocarbon biodegradation studies. It is a component from aliphatic fraction of crude petroleum, commonly related to environmental contamination by diesel oil. Santos Basin is an area with historical petroleum contamination. In the present work, sediment samples from this area were inoculated in artificial seawater (ASW), containing hexadecane as carbon source. Six bacterial isolates were selected as resistant to hexadecane. Chromatographic results showed biodegradation indexes above 97%. After 48 h of culture, five of them could degrade >80% of the initial hexadecane added. These isolates were characterized by 16S rDNA gene sequencing analysis. The following species were found: Bacillus amyloliquefaciens, Staphylococcus epidermidis, Micrococcus luteus, Nitratireductor aquimarinus, and Bacillus pumilus.
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