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Threat of plastic ageing in marine environment. Adsorption/desorption of micropollutants
2018
Kedzierski, Mikaël | D'Almeida, Mélanie | Magueresse, Anthony | Le Grand, Adélaïde | Duval, Hélène | César, Guy | Sire, Olivier | Bruzaud, Stéphane | Le Tilly, Véronique
Ageing of various plastics in marine environment was monitored after immersion of two synthetic (polyvinylchloride, PVC, and polyethylene terephthalate, PET) and one biodegradable (poly(butylene adipate co-terephtalate), PBAT) plastics for 502days in the bay of Lorient (Brittany, France). Data analysis indicates that aged PVC rapidly releases estrogenic compounds in seawater with a later adsorption of heavy metals; PET undergoes a low weakening of the surface whereas no estrogenic activity is detected; PBAT ages faster in marine environment than PVC. Aged PBAT exhibits heterogeneous surface with some cavities likely containing clay minerals from the chlorite group. Besides, this degraded material occasionally shows a high estrogenic activity. Overall, this study reports, for the first time, that some aged plastics, without being cytotoxic, can release estrogenic compounds in marine environment.
Показать больше [+] Меньше [-]Experimental evidence of warming-induced flowering in the Mediterranean seagrass Posidonia oceanica
2018
Ruiz, J.M. | Marín-Guirao, L. | García-Muñoz, R. | Ramos-Segura, A. | Bernardeau-Esteller, J. | Perets, Mikhaʼel ben Yosef | Sanmartí, N. | Ontoria, Y. | Romero, J. | Arthur, R. | Alcoverro, T. | Procaccini, G.
Sexual reproduction in predominantly clonal marine plants increases recombination favoring adaptation and enhancing species resilience to environmental change. Recent studies of the seagrass Posidonia oceanica suggest that flowering intensity and frequency are correlated with warming events associated with global climate change, but these studies have been observational without direct experimental support. We used controlled experiments to test if warming can effectively trigger flowering in P. oceanica. A six-week heat wave was simulated under laboratory mesocosm conditions. Heating negatively impacted leaf growth rates, but by the end of the experiment most of the heated plants flowered, while controls plants did not. Heated and control plants were not genetically distinct and flowering intensity was significantly correlated with allelic richness and heterozygosity. This is an unprecedented finding, showing that the response of seagrasses to warming will be more plastic, more complex and potentially more resilient than previously imagined.
Показать больше [+] Меньше [-]Seasonal biomass and alginate stock assessment of three abundant genera of brown macroalgae using multispectral high resolution satellite remote sensing: A case study at Ekas Bay (Lombok, Indonesia)
2018
Setyawidati, Nur Azmi R. | Puspita, Maya | Kaimuddin, Awaludin H. | Widowati, Ita | Deslandes, Eric | Bourgougnon, Nathalie | Stiger-Pouvreau, Valérie
The potential of Indonesian bays as alginate producers was assessed by determining the stock of wild brown algae and exploring their biomass as alginophytes at the scale of entire bay, using a combination of field observations, remote sensing high resolution data and GIS tools. Ekas Bay in Lombok Island presented a stock of brown macroalgae which varied with season and species: for Padina the biomass reached 97.85±12.63 and 79.54±2.53tons in May/June and November respectively; for Sargassaceae species, it reached 669.70±109.64 and 147.70±77.97tons in May/June and November respectively. The best alginate yields occurred during the May/June period: Padina could produce 9.10±0.06tons DW of alginates. Interestingly, Sargassum/Turbinaria together allow 207.61±0.42tons DW of alginates. This study suggests that wild Sargassaceae represent an interesting stock in terms of biomass, alginate yield and M/G ratio.
Показать больше [+] Меньше [-]A modeling approach for reposition dynamics of litter composition in coastal areas of the city of Santos, Sao Paulo, Brazil
2018
Cordeiro, Taynara Cristina | Barrella, Walter | Butturi-Gomes, Davi | Petrere Jr., Miguel (Petrere Junior)
Given the complexity of the dynamics in litter reposition, our objective was modeling the possible main and interaction effects of tidal oscillations, seasons of the year and the moon phases over the solid waste in Santos beaches. A total of 80 collections were carried out using quadrat sampling, from which we classified, counted and weighed all residue items. We fitted mixed Hurdle models to the output datasets and performed hypotheses tests based on this framework. We found plastic to be the most abundant residue in all seasons, moon phases and tides, followed by Styrofoam and wood. Our models suggest the strongest effect was due to seasonal variations, which, in turn, may be related to different human activities. Although the dynamics of different components showed independency of all interaction structures, plastics depended on the interaction of tide and season, whose impact over estuarine life and ecosystem services shall be further investigated.
Показать больше [+] Меньше [-]Evidence of marine debris usage by the ghost crab Ocypode quadrata (Fabricius, 1787)
2018
Costa, Leonardo Lopes | Rangel, Danilo Freitas | Zalmon, Ilana Rosental
Sandy beaches are sites of marine debris stranding, but the interaction of beach biota with waste is poorly studied. The objective of this study was to investigate whether the ghost crab Ocypode quadrata selects marine debris by types using a non-destructive method on sandy beaches of Southeastern Brazil. We found marine debris in 7% of 1696 surveyed burrows, and the ghost crabs selectivity was mainly by soft plastic (30%), straw (11%), rope (6%) and foam (4%). Burrows with marine debris showed higher occupation rate (~68%) compared to burrows without debris (~28%), indicating that these materials may increase the capacity of ghost crabs to memorize their burrows placement (homing). The percentage of marine debris was not always related to their amount in the drift line, but ghost crabs used more debris near urbanized areas. Future studies should test whether ghost crabs are using marine debris for feeding, homing or other mechanisms.
Показать больше [+] Меньше [-]Antimicrobial resistance and pulsed-field gel electrophoresis typing of Vibrio parahaemolyticus isolated from shrimp mariculture environment along the east coast of China
2018
Zhao, Shu | Ma, Licai | Wang, Yuan | Fu, Guihong | Zhou, Junfang | Li, Xincang | Fang, Wenhong
Environmental antimicrobial resistance (AMR) has drawn increasing attention due to its great risk to human health. The aim of this study was to investigate AMR and genotyping of Vibrio parahaemolyticus isolates (n = 114) recovered from shrimp mariculture environment in China. The isolates exhibited a high rate of resistance to streptomycin (78.9%), ampicillin (64.9%) and gentamicin (53.5%). Furthermore, multi-drug resistance was highly prevalent (61.4%), in which 95.9% of these ampicillin-resistant isolates were primarily mediated by blaCARB-17. Surprisingly, doxycylcine, florfenicol, and trimethoprim/sulfamethoxazole (TMP/SMZ) resistance genes occurred in susceptible isolates. Moreover, 114 isolates were grouped into unique pulsed field gel electrophoresis patterns. These findings suggest the need for the prudent use of antimicrobial agents on mariculture farms, in order to control the dissemination of antimicrobial resistant V. parahaemolyticus.
Показать больше [+] Меньше [-]Underwater noise from airplanes: An overlooked source of ocean noise
2018
Erbe, Christine | Williams, Rob | Parsons, Miles | Parsons, Sylvia K. | Hendrawan, I Gede | Dewantama, I Made Iwan
The effects of underwater noise pollution on marine life are of increasing concern. Research and management have focussed on the strongest underwater sound sources. Aerial sound sources have understandably been ignored as sound transmits poorly across the air-water interface. However, there might be situations when air-borne noise cannot be dismissed. Commercial passenger airplanes were recorded in a coastal underwater soundscape exhibiting broadband received levels of 84–132 dB re 1 μPa rms. Power spectral density levels of airplane noise underwater exceeded ambient levels between 12 Hz and 2 or 10 kHz (depending on site) by up to 36 dB. Underwater noise from airplanes is expected to be audible to a variety of marine fauna, including seals, manatees, and dolphins. With many of the world's airports lying close to the coast, it is cautioned that airplane noise not be ignored, in particular in the case of at-risk species in small, confined habitats.
Показать больше [+] Меньше [-]Critical evaluation of different methods to calculate the Geoaccumulation Index for environmental studies: A new approach for Baixada Santista – Southeastern Brazil
2018
Kim, Bianca Sung Mi | Angeli, José Lourenço Friedmann | Ferreira, Paulo Alves Lima | de Mahiques, Michel Michaelovich | Figueira, Rubens Cesar Lopes
Although the Igeo is widely used in heavy metal contamination studies, its application differs in each study in terms of the mathematical equation used, the chosen background, and whether the fine fraction or whole sediment matrix is used. This study aims to assess these different methods, propose a new equation to calculate this index and use the index to evaluate the environmental quality of Baixada Santista. The levels of heavy metals were quantified in fifty sediment samples using both in the whole sediment sample and only in the fine fraction. The index was calculated in both fractions and in the normalized levels. Using the fine fraction of the sample was more suitable to the classification. The ratio of the levels in the whole sediment to the fine content did not present a significant statistical difference compared to the levels obtained from the fine fraction. Based on this study, a new equation is proposed for use in future environmental studies.
Показать больше [+] Меньше [-]Marine litter on the seafloor of the southern Baltic
2018
Urban-Malinga, Barbara | Wodzinowski, Tycjan | Witalis, Bartosz | Zalewski, Mariusz | Radtke, Krzysztof | Grygiel, Włodzimierz
Marine litter occurrence and composition were investigated during routine bottom trawl fish surveys type BITS performed in the Polish Maritime Areas (the southern Baltic Sea). Sampling covered a distance of 325km and an area of 16km² at a depth range of 19–110m. Litter densities varying between 0 items/ha (34% of tows) and 2.23items/ha with a mean of 0.20items/ha (SD=0.30) are at the bottom range of densities reported from other shelf habitats worldwide at similar water depths. The majority of the items (40%) were found at a depth range of 51–60m. Overall, plastic was the most common litter type (67% of all items) found in all tows with litter. The results of this study indicate that despite the Baltic being a semi-enclosed basin, with a densely populated coastline and extensive shipping, marine litter pollution of the southern Baltic seafloor is low compared to other coastal areas.
Показать больше [+] Меньше [-]Challenges in rendering Coral Triangle habitat richness in remotely sensed habitat maps: The case of Bunaken Island (Indonesia)
2018
Ampou, Eghbert Elvan | Ouillon, Sylvain | Andréfouët, Serge
The Coral Triangle is the epicenter of marine biodiversity, yet the numbers of habitats that can be found on coral reefs remain poorly described. First surveys for habitat mapping in Indonesia revealed a high number of habitats (>150) even for structurally simple reefs. To be able to represent all these habitats, typical habitat mapping procedures and performances are poorly effective even using very high resolution satellite images. Using Bunaken Island (North Sulawesi, Indonesia) as a case study, we devised a way to maintain all the in situ habitat information in remote sensing habitat map products without loss and with mapping procedures based on photo-interpretation. The result is a product which is consistent with a per-polygon fuzzy classification. As such, it is a complex product that meets our habitat representation goal, but its complexity can also limit its immediate use by managers and conservation planners when analyses per habitat are needed.
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