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Accurate assessment of the impact of salmon farming on benthic sediment enrichment using foraminiferal metabarcoding Full text
2015
Pochon, X. | Wood, S.A. | Keeley, N.B. | Lejzerowicz, F. | Esling, P. | Drew, J. | Pawlowski, J.
Assessing the environmental impact of salmon farms on benthic systems is traditionally undertaken using biotic indices derived from microscopic analyses of macrobenthic infaunal (MI) communities. In this study, we tested the applicability of using foraminiferal-specific high-throughput sequencing (HTS) metabarcoding for monitoring these habitats. Sediment samples and physico-chemical data were collected along an enrichment gradient radiating out from three Chinook salmon (Oncorhynchus tshawytscha) farms in New Zealand. HTS of environmental DNA and RNA (eDNA/eRNA) resulted in 1,875,300 sequences that clustered into 349 Operational Taxonomic Units. Strong correlations were observed among various biotic indices calculated from MI data and normalized fourth-root transformed HTS data. Correlations were stronger using eRNA compared to eDNA data. Quantile regression spline analyses identified 12 key foraminiferal taxa that have potential to be used as bioindicator species. This study demonstrates the huge potential for using this method for biomonitoring of fish-farming and other marine industrial activities.
Show more [+] Less [-]Particulate matter in ambient air and its association with alterations in lung functions and respiratory health problems among outdoor exercisers in National Capital Region, India Full text
2015
Kesavachandran, Chandrasekharan Nair | Kamal, Ritul | Bihari, Vipin | Pathak, Manoj Kumar | Singh, Amarnath
Regular exercise improves physiological processes and yields positive health outcomes. However, it is relatively less known that exposure to air pollution during outdoor exercises may actually exacerbate several health problems. The present cross–sectional study was undertaken to assess the particulate matter (PM) in the ambient air and its association with lung functions, pulse rate and respiratory problems among 378 outdoor exercisers in the National Capital Region (NCR), India. Lung functions were measured using a Spirometer (PIKO–1, PIKO–6) and respiratory problems were recorded through a questionnaire–based survey. Concentrations of particulate matter smaller than 2.5 and 1 microns were monitored at 10 locations across the study area using an online automated ambient air monitoring instrument–HAZ–DUST (EPAM–5000). Decline in Forced Expiratory Volume in 1 sec–FEV1 (p<0.001) and Peak Expiratory Flow Rate–PEFR (p<0.001) was observed among the outdoor exercisers compared to the Indian reference values. Ambient air monitoring showed higher PM2.5 concentrations at all the study locations compared to the recommended permissible levels for residential areas in India. Risk of FEV1 (%) predicted cases with <80% showed an increase from 2.32% to 8.69% among the exercisers with respect to PM1 concentration from lower to higher limit at the study locations. Similarly, PEFR showed an increased risk of predicted cases <80% from 0.78% to 2.91% among outside exercisers for lower to higher limit of PM1 concentration. Cases with FEV1 predicted <80% increased from 2.56% to 13.98% and for PEFR from 0.96% to 5.24% among outdoor exercisers for the corresponding lower to higher limits of PM2.5 concentrations. The study demonstrates that outdoor exercisers in locations with high PM concentrations are at a risk of lung function impairment. These impairments are due to deposition of PM in the smaller and larger airways.
Show more [+] Less [-]Sample port design for ballast water sampling: Refinement of guidance regarding the isokinetic diameter Full text
2015
Wier, Timothy P. | Moser, Cameron S. | Grant, Jonathan F. | First, Matthew R. | Riley, Scott C. | Robbins-Wamsley, Stephanie H. | Drake, Lisa A.
By using an appropriate in-line sampling system, it is possible to obtain representative samples of ballast water from the main ballast line. An important parameter of the sampling port is its “isokinetic diameter” (DISO), which is the diameter calculated to determine the velocity of water in the sample port relative to the velocity of the water in the main ballast line. The guidance in the U.S. Environmental Technology Verification (ETV) program protocol suggests increasing the diameter from 1.0× DISO (in which velocity in the sample port is equivalent to velocity in the main line) to 1.5–2.0× DISO. In this manner, flow velocity is slowed—and mortality of organisms is theoretically minimized—as water enters the sample port. This report describes field and laboratory trials, as well as computational fluid dynamics modeling, to refine this guidance. From this work, a DISO of 1.0–2.0× (smaller diameter sample ports) is recommended.
Show more [+] Less [-]Spatial variation, fractionation and sedimentary records of mercury in the East China Sea Full text
2015
Duan, Li-Qin | Song, Jin-Ming | Yu, Yu | Yuan, Hua-Mao | Li, Xue-Gang | Li, Ning
Surface and core sediments were collected to study distributions, phases and potential environmental risk of Hg and to reconstruct anthropogenic Hg change over the past one hundred years in the East China Sea (ECS). Hg contents in surface sediments displayed a decreasing gradient from the Changjiang Estuary to the outer sea. Sequential extraction analysis showed that Hg mainly existed as residual fraction (70.18% of total), and while organic matter fraction (22.96% of total) was the main component of labile fraction, indicating the strong adsorption of organic matters on Hg. Enrichment factor and sediment quality guidelines suggested that Hg in sediments of ECS were at minor enrichment and low adverse effect. Temporal distributions of total Hg content, labile fraction, burial flux and anthropogenic Hg flux showed that anthropogenic Hg input increased since the 1960s, which was related to riverine input and atmospheric transport.
Show more [+] Less [-]Assessing the viability of microorganisms in the ballast water of vessels transiting the North Atlantic Ocean Full text
2015
Steichen, Jamie L. | Quigg, Antonietta
Testing phytoplankton viability within ballast tanks and receiving waters of ballast water discharge remain understudied. Potentially harmful dinoflagellates and diatoms are transported via ballast water to Galveston Bay, Texas (USA), home to three major ports: Houston, Texas City and Galveston. Ballast water from vessels transiting the North Atlantic Ocean was inoculated into treatments representing low and high salinity conditions similar to the Ports of Houston and Galveston respectively. Phytoplankton in ballast water growout experiments were deemed viable and showed growth in low and mid salinities with nutrient enrichment. Molecular methods identified several genera: Dinophysis, Gymnodinium, Gyrodinium, Heterocapsa, Peridinium, Scrippsiella, Chaetoceros and Nitzschia. These phytoplankton genera were previously identified in Galveston Bay except Scrippsiella. Phytoplankton, including those capable of forming harmful algal blooms leading to fish and shellfish kills, are transported to Galveston Bay via ballast water, and are viable when introduced to similar salinity conditions found in Galveston Bay ports.
Show more [+] Less [-]Studies on polycyclic aromatic hydrocarbons in surface sediments of Mithi River near Mumbai, India: Assessment of sources, toxicity risk and biological impact Full text
2015
Singare, Pravin U.
This study investigated the levels, sources and potential risks of 17 polycyclic aromatic hydrocarbons in surface sediment samples collected along the Mithi River of Mumbai. The concentration level of ΣPAHs found in the present study was in the range of 1206–4735ng/gdw. The composition patterns of PAHs by ring size in sediment were surveyed which indicate the dominance of four rings followed by five and three ring PAHs. In the study it was observed that the high molecular weight PAHs (HMW PAHs) made greater contributions of 90.83% as compared to that of low molecular PAHs (LMW PAHs) contributing to 9.17% to the total PAH concentrations. Toxicity and biological risk were assessed using toxic equivalent quantity and sediment quality guideline quotient. It is feared that the pollution level of PAHs in the sediments might increase in coming times resulting in an unconspicuous risks for the environment and humans through food chains.
Show more [+] Less [-]Characterizing the parent and oxygenated polycyclic aromatic hydrocarbons in mangrove sediments of Hong Kong Full text
2015
Wang, Xiaowei | Yuan, Ke | Yang, Lihua | Lin, Li | Tam, Nora F.Y. | Chen, Baowei | Luan, Tiangang
Parent and oxygenated polycyclic aromatic hydrocarbons (PAHs) were investigated in mangrove sediments of Hong Kong. Most of the analytes were detected, and the dominant carbonylic and hydroxylated PAHs in mangrove sediments were 9-fluorenone and 2-hydroxy fluorene, respectively. The concentration of 9-fluorenone and 9,10-anthraquinone was higher than their parent PAHs. Moreover, the concentration of total organic matter (TOM) related with those of the parent PAHs and carbonylic PAHs, except for hydroxylated PAHs, which indicated that TOM was not the only factor regulating the distribution of oxygenated PAHs. Nevertheless, the parent PAHs in mangrove sediments was correlated positively with carbonylic PAHs which demostrated not only the similar source but also the fate of these two compound class. However, hydroxylated PAHs had different source by comparing with parent PAHs and carbonylic PAHs, they were probably originated from biodegradation and accumulated in mangrove sediments.
Show more [+] Less [-]First evidence of presence of plastic debris in stomach of large pelagic fish in the Mediterranean Sea Full text
2015
Romeo, Teresa | Pietro, Battaglia | Pedà, Cristina | Consoli, Pierpaolo | Andaloro, Franco | Fossi, Maria Cristina
This study focuses, for the first time, on the presence of plastic debris in the stomach contents of large pelagic fish (Xiphias gladius, Thunnus thynnus and Thunnus alalunga) caught in the Mediterranean Sea between 2012 and 2013. Results highlighted the ingestion of plastics in the 18.2% of samples. The plastics ingested were microplastics (<5mm), mesoplastics (5–25mm) and macroplastics (>25mm).These preliminary results represent an important initial phase in exploring two main ecotoxicological aspects: (a) the assessment of the presence and impact of plastic debris on these large pelagic fish, and (b) the potential effects related to the transfer of contaminants on human health.
Show more [+] Less [-]Inactivation of microalgae in ballast water with pulse intense light treatment Full text
2015
Feng, Daolun | Shi, Jidong | Sun, Dan
The exotic emission of ballast water has threatened the coastal ecological environment and people’s health in many countries. This paper firstly introduces pulse intense light to treat ballast water. 99.9±0.09% inactivation of Heterosigma akashiwo and 99.9±0.16% inactivation of Pyramimonas sp. are observed under treatment conditions of 350V pulse peak voltage, 15Hz pulse frequency, 5ms pulse width and 1.78L/min flow rate. The energy consumption of the self-designed pulse intense light treatment system is about 2.90–5.14 times higher than that of the typical commercial UV ballast water treatment system. The results indicate that pulse intense light is an effective technique for ballast water treatment, while it is only a competitive one when drastic decreasing in energy consumption is accomplished.
Show more [+] Less [-]A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples Full text
2015
Song, Young Kyoung | Hong, Sang Hee | Jang, Mi | Han, Gi Myung | Rani, Manviri | Lee, Jongmyoung | Shim, Won Joon
The analysis of microplastics in various environmental samples requires the identification of microplastics from natural materials. The identification technique lacks a standardized protocol. Herein, stereomicroscope and Fourier transform infrared spectroscope (FT-IR) identification methods for microplastics (<1mm) were compared using the same samples from the sea surface microlayer (SML) and beach sand. Fragmented microplastics were significantly (p<0.05) underestimated and fiber was significantly overestimated using the stereomicroscope both in the SML and beach samples. The total abundance by FT-IR was higher than by microscope both in the SML and beach samples, but they were not significantly (p>0.05) different. Depending on the number of samples and the microplastic size range of interest, the appropriate identification method should be determined; selecting a suitable identification method for microplastics is crucial for evaluating microplastic pollution.
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