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Mysterious oil spill in the Atlantic Ocean threatens marine biodiversity and local people in Brazil
2020
Magris, Rafael Almeida | Giarrizzo, Tommaso
This study provides the first preliminary assessment of the potential impact from the recent oil spill in the Southern Atlantic Ocean. Using information on the occurrence of oil patches along the Brazilian coast, we quantified potential exposure of marine coastal habitats (estuaries, mangroves, beaches, seagrass meadows, tidal flats, and coral reefs) to oil-related disturbances. We also evaluated which threatened species in the coastal zone may have been impacted and the magnitude of the impacts on socioeconomic activities (i.e. artisanal fisheries and local tourism). Estuaries, mangroves, and seagrass meadows had the highest footprint among the habitats assessed. A total of 27 threatened coastal species occur within the area impacted by the oil residue. Approximately 870,000 people, employed in both artisanal fisheries and local tourism, appear to have been affected by the oil spill. We pinpointed priority areas for monitoring of contamination and accumulation in marine biota.
Mostrar más [+] Menos [-]Spatial variability of phthalates contamination in the reef-building corals Porites lutea, Pocillopora verrucosa and Pavona varians
2020
Montano, Simone | Seveso, Davide | Maggioni, Davide | Galli, Paolo | Corsarini, Stefano | Saliu, Francesco
Microplastic pollution represents a serious hazard for the marine environment, including coral reefs. Scleractinian corals can easily mistake microplastics with their natural preys, and ingest them and all the annexed plasticizer additives. Here we selectively searched on field for five phthalates esters (PAEs) namely dibutyl-phthalate (DBP), benzylbutyl-phthalate (BBzP), diethyl-phthalate (DEP), Bis(2-ethylhexyl)-phthalate (DEHP), and dimethyl-phthalate (DMP) in the coral species Pocillopora verrucosa, Porites lutea and Pavona varians. Our data reveal that >95% of corals sampled were contaminated, with a maximum of 172.4 ng/g, a value 7 time-fold higher than those found in a previous study. The Σ₅ PAEs showed an average of about 30 ng/g per coral, but no differences in PAEs contamination was detected between species, depth or reef exposure. Despite their effects on coral physiology are not yet known, PAEs should be now considered as a novel, and ubiquitous, form of contamination in corals.
Mostrar más [+] Menos [-]210Pb dating to investigate the historical variations and identification of different sources of heavy metal pollution in sediments of the Pearl River Estuary, Southern China
2020
Ye, Zhiping | Chen, Jianyao | Gao, Lei | Liang, Zuobing | Li, Shaoheng | Li, Rui | Jin, Guangzhe | Shimizu, Yuta | Onodera, Shin-ichi | Saito, Mitsuyo | Gopalakrishnan, Gnanachandrasamy
In this study, we investigated the historical variation, source identification, and distribution of heavy metal pollution in sediments of the Pearl River Estuary (PRE) using ²¹⁰Pb dating. Our results suggest that the heavy metal concentrations were higher in the western part of the estuary. For all heavy metals, Cd was significantly enriched in the sediments. The Pearl River Delta (PRD) has experienced rapid economic development in the past 40 years, a decreasing trend in heavy metal fluxes after 2004 was identified, which suggests a reduction in heavy metal concentrations due to the removal of heavy polluting industries and the effective control of sewage discharge. A binary mixing model reveals that the contributions of anthropogenic Pb ranged from 45.4 to 64%. Based on lead isotopic ratios (²⁰⁶/²⁰⁷Pb and ²⁰⁸/²⁰⁶Pb), it was found that geologic materials and industrial pollution were the main sources of heavy metals in the PRE sediments.
Mostrar más [+] Menos [-]Selective extraction and detection of norfloxacin from marine sediment and seawater samples using molecularly imprinted silica sorbents coupled with HPLC
2020
Qin, Dan | Zhao, Min | Wang, Jiangtao | Lian, Ziru
A simple, sensitive and effective method was developed and validated for selective adsorption and quantitation of norfloxacin (NFX) from marine sediments and seawater samples using the novel molecularly imprinted silica polymers as sorbents followed by high-performance liquid chromatographic analysis with diode array detection (HPLC-DAD). The imprinted particles were characterized by different techniques and the molecular recognition for NFX was also investigated. Several parameters affecting the extraction efficiency of molecularly imprinted solid-phase extraction (MISPE) process were optimized. Three sediment and seawater samples from Weihai bay in China were analyzed and the results show that satisfactory recoveries (77.2–98.7%) were achieved in seawater samples with low relative standard deviation (RSD) values less than 6.89% (n = 3), and the recoveries in sediments were in the range of 75.5–91.7%. The limits of detection are respectivley 2 μg L⁻¹ in seawater samples and 5 μg kg⁻¹ in sediments.
Mostrar más [+] Menos [-]Blue-Green Algae in Surface Water: Problems and Opportunities
2020
Vu, Hang P. | Nguyen, Luong N. | Zdarta, Jakub | Nga, Tran T. V. | Nghiem, Long D.
PURPOSE OF REVIEW: Cyanobacteria, commonly known as blue-green algae, are often seen as a problem. Their accumulation (bloom) in surface water can cause toxicity and aesthetic concerns. Efforts have been made in preventing and managing cyanobacterial blooms. By contrast, purposeful cultivation of cyanobacteria can create great opportunities in food, chemical and biofuel applications. This review summarises the current stage of research and the socio-economic impacts associated with both the problems and opportunities induced from the presence of cyanobacteria in surface water. RECENT FINDINGS: Insightful knowledge of factors that trigger cyanobacterial blooms has allowed for the development of prevention and control strategies. Advanced technologies are utilised to detect, quantify and treat cyanobacterial biomass and cyanotoxins in a timely manner. Additionally, understanding of cyanobacterial biochemical properties enables their applications in food and health industry, agriculture and biofuel production. Researchers have been able to genetically modify several cyanobacterial strains to obtain a direct pathway for ethanol and hydrogen production. Cyanobacterial blooms have been effectively addressed with advances technologies and cyanobacterial research. However, this review identified a knowledge gap regarding cyanotoxin synthesis and the relevant environmental triggers. This information is essential for developing measures to prevent cyanobacterial blooms. Additionally, this review affirms the promising opportunities that cyanobacteria offer in the food, cosmetics, pigments and agriculture. Biofuel production from cyanobacterial biomass presents an immense potential but is currently constrained by the cultivation process. Thus, future research should strive to achieve effective mass harvesting of cyanobacterial biomass and obtain a profound understanding of cyanotoxin production.
Mostrar más [+] Menos [-]Tropical shrimp aquaculture farms harbour pathogenic Vibrio parahaemolyticus with high genetic diversity and Carbapenam resistance
2020
Narayanan, Sreejith V. | Joseph, Toms C. | Peeralil, Shaheer | Koombankallil, Reshmi | Vaiyapuri, Murugadas | Mothadaka, Mukteswar P. | Lalitha, Kuttanapilly V.
In characterization of food borne pathogens from the environment, assessment of virulence, genetic diversity and AMR are essential preludes to formulate preventive strategies and to combat the spread. This study aimed to identify and characterize pathogenic Vibrio parahaemolyticus in the coastal aquaculture farms of Kerala, India. Twenty-seven β-haemolytic V. parahaemolyticus were isolated from 7 out of 40 farms studied. Among the 27 isolates, 15 possessed the tdh gene and 4 had trh. ERIC PCR and PFGE illustrated the presence of pathogenic isolates that shared genetic similarity with clinical strains. One pathogenic isolate was identified to be multidrug resistant (MDR) and 59% exhibited a MAR index of 0.2 or above. Seventy four percent of the pathogenic isolates were ESBL producers and 3.7% of them were carbapenemase producers phenotypically. This asks for adoption of control measures during farming to prevent the transmission of pathogenic V. parahaemolyticus to the environment and food chain.
Mostrar más [+] Menos [-]Bioremediation as a promising strategy for microplastics removal in wastewater treatment plants
2020
Masiá, Paula | Sol, Daniel | Ardura, Alba | Laca, Amanda | Borrell, Yaisel J. | Dopico, Eduardo | Laca, Adriana | Machado-Schiaffino, Gonzalo | Díaz, Mario | García Vázquez, Eva
Microplastics (MPs) attract ever-increasing attention due to environmental concerns. Nowadays, they are ubiquitous across ecosystems, and research demonstrates that the origin is mainly terrestrial. Wastewater treatment plants (WWTPs) are a major source of MPs, especially fibres, in water masses. This review is focused on understanding the evolution and fate of microplastics during wastewater treatment processes with the aim of identifying advanced technologies to eliminate microplastics from the water stream. Among them, bioremediation has been highlighted as a promising tool, but confinement of microorganisms inside the WWTP is still a challenge. The potential for MPs bioremediation in WWTPs of higher aquatic eukaryotes, which offer the advantages of low dispersion rates and being easy to contain, is reviewed. Animals, seagrasses and macrophytes are considered, taking into account ecoethical and biological issues. Necessary research and its challenges have been identified.
Mostrar más [+] Menos [-]Competitive advantages of Ulva prolifera from Pyropia aquaculture rafts in Subei Shoal and its implication for the green tide in the Yellow Sea
2020
Hao, Ya | Qu, Tongfei | Guan, Chen | Zhao, Xinyu | Hou, Chengzong | Tang, Xuexi | Wang, Ying
The physiological characteristics of Ulva prolifera and Blidingia sp. during two pre-bloom stages (March & May) were compared to evaluate the competitive advantage of U. prolifera on Pyropia aquaculture rafts in Subei Shoal. (1) Compared to Blidingia sp., U. prolifera had a lower growth rate, chlorophyll content, photosynthetic efficiency, and antioxidant capacity in March. (2) In May, various indicators of U. prolifera's physiological function improved significantly, while the antioxidant capacity of Blidingia sp. decreased significantly. Large lipidic globules in U. prolifera cells became scattered small lipidic globules in May, which indicated a decrease in lipid membrane peroxidation. (3) In U. prolifera, the ratio of buoyancy to gravity of per unit volume was 1.73, and the bubbles inside the thalli provided 60% of the total buoyancy. Buoyancy generated by the inflatable structure of U. prolifera allowed this species to float after being separated from the rafts.
Mostrar más [+] Menos [-]Microplastic ingestion by pelagic and benthic fish and diet composition: A case study in the NW Iberian shelf
2020
Filgueiras, Ana Virginia | Preciado, Izaskun | Cartón, Ana | Gago, Jesús
We evaluated the incidence of microplastics in the digestive tract contents of four fish species: Engraulis encrasicolus, Sardina pilchardus, Callionymus lyra and Mullus surmuletus. Alkaline digestion (10% KOH) was used to degrade the organic matter. The percentage of fish with microplastics was 78% (88% fibres, 12% fragments). The main types of polymers identified by Raman spectroscopy were polyethylene and polypropylene. The diet of the four species was also studied and two feeding types were determined: plankton-feeders and benthic-feeders. The effect of a set of biological variables (Length, Fullness index, Fulton's condition factor and Feeding type) on the number and size of microplastics ingested was studied using Generalised Additive Models (GAMs). A significant increase in the number of microplastics with increasing length was observed. No significant effect of trophic variables (fullness index and feeding type) on the number and size of microplastics was found.
Mostrar más [+] Menos [-]Sediment quality of the Bohai Sea and the northern Yellow Sea indicated by the results of acid-volatile sulfide and simultaneously extracted metals determinations
2020
Gao, Xuelu | Song, Jinming | Li, Xuegang | Yuan, Huamao | Zhao, Jianmin | Xing, Qianguo | Li, Peimiao
The surface sediments from the Bohai Sea (BS) and the northern Yellow Sea (NYS) were analyzed for acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) to assess the sediment quality. The results indicated that >60% of the samples were found to have possible adverse effects on aquatic life in the BS based on the difference between the concentrations of AVS ([AVS]) and SEM ([SEM]), and the corresponding percentage in the NYS was <25%. Nevertheless, there was no indication of adverse effects for all the BS and the NYS samples when the total organic carbon (TOC) concentration was introduced in the sediment quality evaluation with [AVS] and [SEM]. The grain size composition, TOC, water content and pH all had significant influence on the distribution of [SEM] and the [SEM]/[AVS] ratios; while, in contrast, the distribution of [AVS] could be mainly determined by the redox condition of sediment.
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