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Virulence, resistance, and genetic diversity of Vibrio parahaemolyticus recovered from commonly consumed aquatic products in Shanghai, China
2020
Su, Chenli | Chen, Lanming
Vibrio parahaemolyticus can cause severe gastroenteritis, septicaemia and even death in humans. Continuous monitoring of V. parahaemolyticus contamination in aquatic products is imperative for ensuring food safety. In this study, we isolated and characterized 561 V. parahaemolyticus strains recovered from 23 species of commonly consumed shellfish, crustaceans, and fish collected in July and August of 2017 in Shanghai, China. The bacterium was not isolated from two fish species Carassius auratus and Parabramis pekinensis. The results revealed a very low occurrence of pathogenic V. parahaemolyticus carrying the toxin genes trh (0.2%) and tdh (0.0%). However, high percentages of resistance to the antimicrobial agents ampicillin (93.0%), rifampin (82.9%), streptomycin (75.4%) and kanamycin (50.1%) were found. A high incidence of tolerance to the heavy metals Hg²⁺ (74.7%) and Zn²⁺ (56.2%) was also observed in the isolates. ERIC-PCR-based fingerprinting of MDR isolates (77.5%) revealed 428 ERIC-genotypes, demonstrating remarkable genetic variation among the isolates. The results of this study support the urgent need for food safety risk assessment of aquatic products.
Afficher plus [+] Moins [-]High abundance of Vibrio in tarball-contaminated seawater from Vagator beach, Goa, India
2020
Fernandes, Clafy | Khandeparker, Rakhee D.S. | Shenoy, Belle Damodara
Tarballs are semi-solid remnants of crude oil and they are formed in marine environment after oil-spill incidents. They are composed of diverse hydrocarbons; some of which are recalcitrant in nature. Recent studies based on amplicon sequencing of 16S rRNA gene suggested that tarballs support hundreds of bacterial genera and provided insights into their role as hydrocarbon degraders and potential human pathogens. In this study, bacterial composition of tarball-contaminated seawater from Vagator beach, Goa, India was characterized by amplicon sequencing of V₃–V₄ regions of 16S rRNA gene. The DNA data revealed an unusual surge of Vibrio in sea-water contaminated with tarballs in May 2018 (16.16% OTUs), compared to tarball-free seawater samples collected in March 2018 (no detectable OTUs) and September 2018 (0.17% OTUs). Further studies are required to investigate if Vibrio species form biofilms on tarballs which may act as good reservoirs for their survival and transmission success.
Afficher plus [+] Moins [-]Oil spill from the Era: Mangroves taking eons to recover
2020
Connolly, Rod M. | Connolly, Finnian N. | Hayes, Matthew A.
Mangroves are highly susceptible to oil exposure. Depending on the severity, oil exposure can result in initial defoliation and eventual recovery through to mass mortality and complete loss of habitat. Some aspects of the impact of oil on mangroves and their recovery are well studied, but the focus has been on short-term responses, and the understanding of the longer-term trajectory of mangrove recovery from oiling is very limited. Here, we combine field results from sampling in the two years following a significant oiling event, with analysis of canopy cover in aerial images from before the event to 26 years afterwards. Approximately 100 ha of a monospecific stand of Avicenna marina mangroves were oiled as a result of a spill from the Era tanker in Spencer Gulf in southern Australia in September 1992. While lightly oiled trees made a full recovery, trees in heavily oiled areas experienced mass defoliation and ultimately mortality within several months of the oiling event. An analysis of aerial images indicated that there was no recovery in heavily oiled areas for 10 years following the oiling event. Between 10 and 25 years, seedling establishment and growth saw canopy cover increase to 35% of pre-oiling cover within heavily oiled areas. Predictive modelling estimates that complete recovery of mangroves to pre-oiling cover will take 55 years (median prediction in 2047). Our findings indicate that although mangroves can recover following a heavy oiling event, the rate of recovery can be slow, with full recovery in the order of half a century, much longer than has previously been anticipated.
Afficher plus [+] Moins [-]Effects of marine noise pollution on Mediterranean fishes and invertebrates: A review
2020
Di Franco, E. | Pierson, P. | Di Iorio, L. | Calò, A. | Cottalorda, J.M. | Derijard, B. | Di Franco, A. | Galvé, A. | Guibbolini, M. | Lebrun, J. | Micheli, F. | Priouzeau, F. | Risso-de Faverney, C. | Rossi, F. | Sabourault, C. | Spennato, G. | Verrando, P. | Guidetti, P.
Marine noise pollution (MNP) can cause a multitude of impacts on many organisms, but information is often scattered and general outcomes difficult to assess. We have reviewed the literature on MNP impacts on Mediterranean fish and invertebrates. Both chronic and acute MNP produced by various human activities - e.g. maritime traffic, pile driving, air guns - were found to cause detectable effects on intra-specific communication, vital processes, physiology, behavioral patterns, health status and survival. These effects on individuals can extend to inducing population- and ecosystem-wide alterations, especially when MNP impacts functionally important species, such as keystone predators and habitat forming species. Curbing the threats of MNP in the Mediterranean Sea is a challenging task, but a variety of measures could be adopted to mitigate MNP impacts. Successful measures will require more accurate information on impacts and that effective management of MNP really becomes a priority in the policy makers' agenda.
Afficher plus [+] Moins [-]Biological Aerosol Particles in Polluted Regions
2020
Hu, Wei | Wang, Zihan | Huang, Shu | Ren, Lujie | Yue, Siyao | Li, Ping | Xie, Qiaorong | Zhao, Wanyu | Wei, Lianfang | Ren, Hong | Wu, Libin | Deng, Junjun | Fu, Pingqing
PURPOSE OF REVIEW: Biological aerosol particles play a crucial role in the Earth system, particularly in the land/ocean-atmosphere interactions. This paper aims to summarize the up-to-date research progresses on the characteristics, biomarkers as well as the health-related, climatic and ecological effects of biological aerosol particles in polluted regions, especially in East Asia and South Asia. RECENT FINDINGS: The atmospheric abundance, size distribution, and community structure of microorganisms show differences during haze and non-haze conditions. The long-distance transportation of dust-associated microorganisms influences the abundance and community structure of airborne microbes in downwind areas. Wildfire smoke or biomass burning potentially impacts the release, transport and dispersal of microorganisms in the atmosphere. Meteorological conditions and air pollutants likely interact with airborne microorganisms, pollen, and fluorescent biological aerosol particles. Molecular biomarkers including proteins and amino acids, sugars, and lipid compounds have been used to fingerprint the sources of biological aerosols and give important biogeochemical information of atmospheric aerosols. In addition to pathogenic and allergenic microorganisms and pollen, biological aerosol particles indicated by abundant endotoxins and antibiotic resistance genes could have significant impacts on public health. In polluted regions, the potential influences of biological aerosol particles on climate and ecosystems could be more complex. We comprehensively summarize the recent research progresses on the characteristics, biomarkers, influencing factors, and effects of biological aerosol particles in polluted regions, mostly in East Asia and South Asia. To further understand the complicated effects of biological aerosol particles in polluted regions, the development and application of novel approaches and techniques as well as in-depth investigations on the roles of biological aerosol particles in atmospheric chemistry, cloud formation, and public health need to be implemented.
Afficher plus [+] Moins [-]First marine litter survey on beaches in Solomon Islands and Vanuatu, South Pacific: Using OSPAR protocol to inform the development of national action plans to tackle land-based solid waste pollution
2020
Binetti, U. | Silburn, B. | Russell, J. | van Hoytema, N. | Meakins, B. | Kohler, P. | Desender, M. | Preston-Whyte, F. | Fa'abasu, E. | Maniel, M. | Maes, T.
The increasing abundance of marine litter is impacting the environment, human health and economies in the South Pacific. Small Islands Developing States are particularly affected by marine litter, primarily due to insufficient waste management systems. For the first time, marine litter was quantified and characterised on 13 beaches in Solomon Islands and Vanuatu in the South Pacific region using the OSPAR beach litter monitoring guidelines. A total of 1053 (±1017) and 974 (±745) items of litter per 100 m beach were recorded in Solomon Islands and Vanuatu respectively. Litter composition and distribution show that the majority of the litter comes from local land-based sources and large quantities of fragments and single use plastics were found by cities and river mouths. Actions to reduce single use plastic, improve collection, reuse and recycling, together with outreach campaigns would reduce marine litter significantly in these countries. Furthermore, there is great potential to develop a more circular economy to manage the substantial quantities of recyclable items that were found stranded on the beaches.
Afficher plus [+] Moins [-]Metal pollution and its biological effects in swimming crab Portunus trituberculatus by NMR-based metabolomics
2020
Yu, Deliang | Peng, Xiao | Ji, Chenglong | Li, Fei | Wu, Huifeng
Metal pollution in the Bohai Sea in China has posed a potential risk on marine organisms. In this work, crabs (Portunus trituberculatus) were sampled from four sites, namely a reference (site 3934) and three metal-polluted (sites 6151, 6351, and 3562) sites, located in the Bohai Sea. Metal concentrations in crab gill tissues were measured using inductively coupled plasma mass spectrometry. Cu, Zn, and Cd in crab samples from S3562 presented the highest concentrations. Particularly, Cu concentration exceeded the marine biological quality standard II. Cd contents in crab samples from all metal-polluted sites exceeded the marine biological quality standard I. Nuclear magnetic resonance-based metabolomics indicated metal pollution-induced immune stresses in crab samples from all metal-polluted sites. Metal pollution in S6151 and S6351 disturbed energy metabolism through differential pathways. For crab samples from S3562, the metabolic profile suggested that metal pollution mainly induced osmotic stress.
Afficher plus [+] Moins [-]Seasonal ingestion of anthropogenic debris in an urban population of gulls
2020
Stewart, Lillian G. | Lavers, Jennifer L. | Grant, Megan L. | Puskic, Peter S. | Bond, Alexander L.
Gulls are generalist seabirds, increasingly drawn to urban environments where many species take advantage of abundant food sources, such as landfill sites. Despite this, data on items ingested at these locations, including human refuse, is limited. Here we investigate ingestion of prey and anthropogenic debris items in boluses (regurgitated pellets) from Pacific Gulls (Larus pacificus). A total of 374 boluses were collected between 2018 and 2020 in Tasmania. Debris was present in 92.51% of boluses (n = 346), with plastic (86.63%, n = 324) and glass (64.71%, n = 242) being the most prominent types. An abundance of intact, household items (e.g., dental floss, food wrappers) suggest the gulls regularly feed at landfill sites. In addition, the boluses are deposited at a roosting site located within an important wetland, thus we propose that the gulls may be functioning as a previously unrecognised vector of anthropogenic debris from urban centres to aquatic environments.
Afficher plus [+] Moins [-]Deep-sea meiofauna assemblages with special reference to marine nematodes in the Caiwei Guyot and a Polymetallic Nodule Field in the Pacific Ocean
2020
Zhao, Meihong | Liu, Qinghe | Zhang, Dongsheng | Liu, Zhensheng | Wang, Chunsheng | Liu, Xiaoshou
Meiofauna particularly marine nematodes around the Caiwei Guyot in the northwest Pacific Ocean and a Polymetallic Nodule Field in the northeast Pacific Ocean were studied. Due to the geographic structure, the Caiwei Guyot and the Polymetallic Nodule Field had different environmental characteristics. Meiofaunal abundances around the Guyot area ranged from 9.18 to 25.59 ind./10 cm², which were much lower than those in the Polymetallic Nodule Field. Marine nematode was the most dominant group. A total of 123 species, belonging to 74 genera and 29 families were found. Xyalidae (21.43%), Cyatholaimidae (9.82%), Linhomoeidae (8.03%) were the dominant families. The values of species number, Margalef's species richness and Shannon-Wiener diversity index ranged from 15 to 62, 4.75 to 12.84 and 2.58 to 3.93, respectively. The combination of water depth, silt-clay content and chlorophyll-a concentration can best explain the differences of nematode community. This study provides a baseline for deep-sea meiofauna distribution.
Afficher plus [+] Moins [-]Citizen science reveals microplastic hotspots within tidal estuaries and the remote Scilly Islands, United Kingdom
2020
Nel, Holly A. | Sambrook Smith, Gregory H. | Harmer, Rogan | Sykes, Rebecca | Schneidewind, Uwe | Lynch, Iseult | Krause, Stephan
The identification of microplastic hotspots is vital to our long-term understanding of their environmental fate and distribution. Although case studies have increased globally, sampling campaigns are often restricted geographically, with poor spatial resolution. Here, we use citizen science to increase our geographical reach, which improved our understanding of microplastic distribution in estuarine and beach sediment along the south-west coast of England. Hotspots (>700 particles per kg dry sediment) were identified on the Scilly Islands and in close proximity to major metropolitan hubs (i.e. Falmouth and Plymouth). Particles extracted from the Scilly Island sites were composed of polyethylene and polypropylene. With low population density on the Isle of Scilly, hotspots may suggest that microplastics originate from distant sources, while Falmouth and Plymouth, on mainland UK, are locally supplied. This information supports the design of future campaigns and targeted mitigation strategies in areas of highest concentrations.
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