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Результаты 1921-1930 из 5,152
Microplastics reduced posterior segment regeneration rate of the polychaete Perinereis aibuhitensis Полный текст
2018
Leung, Julia | Chan, Kit Yu Karen
Microplastics are found in abundance in and on coastal sediments, and yet, whether exposure to this emerging pollutant negatively impact whole organism function is unknown. Focusing on a commercially important polychaete, Perinereis aibuhitensis, we demonstrated that presence of microplastics increased mortality and reduced the rate of posterior segment regeneration. The impact of the micro-polystyrene beads was size-dependent with smaller beads (8–12μm in diameter) being more detrimental than those bigger in size (32–38μm). This observed difference suggests microplastic impact could be affected by physical properties, e.g., sinking speed, surface area available for sorption of chemicals and bacteria, and selective feeding behaviors of the target organism.
Показать больше [+] Меньше [-]Addressing the impact of mercury estuarine contamination in the European eel (Anguilla anguilla L., 1758) – An early diagnosis in glass eel stage based on erythrocytic nuclear morphology Полный текст
2018
Castro, D. | Mieiro, C.L. | Coelho, J.P. | Guilherme, S. | Marques, A. | Santos, M.A. | Duarte, A.C. | Pereira, E. | Pacheco, M.
The decline of the European eel (Anguilla anguilla L., 1758) population throughout Europe has been partially attributed to pollution. As glass eel estuarine migration may represent a considerable threat, the impact of mercury (Hg) contamination at this stage was evaluated through an in situ experiment (7days). Total Hg (tHg) bioaccumulation was evaluated concomitantly with erythrocytic nuclear morphology alterations: erythrocytic nuclear abnormalities assay (ENA), frequency of immature erythrocytes (IE) and the erythrocytic maturity index (EMI). The ENA results suggested a genotoxic pressure at the most contaminated sites, in line with the tHg increase. The EMI data, together with IE frequency, showed that fish exposed to high levels of Hg exhibited alterations of haematological dynamics, translated into an erythropoiesis increment. Despite the presence of these compensatory mechanisms, the present findings suggest a harmful impact of Hg on genome integrity at this early development stage, potentially affecting eels' condition and ultimately the population sustainability.
Показать больше [+] Меньше [-]An 87-year sedimentary record of mercury contamination in the Old Yellow River Estuary of China Полный текст
2018
Ge, Meng | Liu, Guijian | Liu, Yuan | Yuan, Zijiao | Liu, Houqi
A sediment core, spanning from the year 1925 ± 3.03 to 2012, was collected for analyzing historical distribution of mercury (Hg) in the Old Yellow River Estuary (OYRE), China. The Hg concentrations in the sediment core ranged from 14 to 351 ng g−1, with the high values occurred in the middle layers (1960–1996), which may be resulted from intensive human activities during this period, such as oil exploitation and booming of petrochemical industry, salt chemical industry and chlor-alkali plants. A significant positive correlation was found between THg and loss on ignition (LOI). The main fraction of Hg existed in residual part while the fraction that was easy to leach out from sediments accounted for only a small portion according to the results of BCR sequential extraction procedure. Multiple ecological risks indices and guidelines of Hg indicated that the sedimentary record presented an “intermediate state” for Hg contamination in the OYRE.
Показать больше [+] Меньше [-]Stable isotopes demonstrate the effectiveness of a tidally-staged sewage release system Полный текст
2018
Kaminski, Hayley L. | Fry, Brian | Warnken, Jan | Pitt, Kylie A.
Nutrient loading from sewage wastewater discharge contributes to the eutrophication of coastal waters. Wastewater from the Gold Coast, Australia is discharged into the Gold Coast Seaway (GCS) for 13.5 h d⁻¹ primarily on the ebbing tide to disperse wastewater seawards. Nitrogen stable isotopes were used to assess how effectively the tidally staged release system dispersed wastewater out of the GCS and identified pathways by which sewage-N was incorporated into food webs. Turf algae, limpets and barnacles were sampled at the GCS, at two coastal sites and at the mouth of a control estuary that lacked point-source discharge. In the GCS δ¹⁵N values of algae and limpets returned to coastal baseline levels within 250 m of the diffusers. In contrast, δ¹⁵N of filter-feeding barnacles did not significantly vary indicating wastewater-N does not dominate the pelagic food web. Nitrogen stable isotopes clearly demonstrated that the tidally-staged wastewater release system effectively disperses wastewater offshore.
Показать больше [+] Меньше [-]Type and quantity of coastal debris pollution in Taiwan: A 12-year nationwide assessment using citizen science data Полный текст
2018
Walther, Bruno A. | Kunz, Alexander | Hu, Chieh-Shen
Man-made coastal debris pollution is a growing concern for Taiwan. In 2004, Taiwanese environmental organizations led by the “Society of Wilderness” began gathering data on 19 categories of debris items collected during cleanup events. We present our analysis of the resulting 12-year dataset collated from 541 events held between October 2004 and December 2016. In total, 904,302 items weighing 131,358.3 kg were collected, and 63.6% and 27.2% of items were made of either plastic or plastic mixed with other materials, respectively. The five most commonly recorded debris categories were plastic shopping bags, plastic bottle caps, disposable tablewares, fishing equipment, and plastic drinking straws. We estimated that during the 12-year period on average between 3.7 and 7.9 million items weighing 560–1110 metric tons polluted Taiwan's coastline. We offer recommendations for improving the quality of data collected during Taiwan's cleanup events and report some policy changes due partly to previous reports of this dataset.
Показать больше [+] Меньше [-]Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms Полный текст
2018
Jung, Melissa R. | Horgen, F David | Orski, Sara V. | Rodriguez C., Viviana | Beers, Kathryn L. | Balazs, George H. | Jones, T Todd | Work, Thierry M. | Brignac, Kayla C. | Royer, Sarah-Jeanne | Hyrenbach, K David | Jensen, Brenda A. | Lynch, Jennifer M.
Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1–6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon.
Показать больше [+] Меньше [-]Integrated toxicity evaluation of metals in sediments of Jiaozhou Bay (China): Based on biomarkers responses in clam Ruditapes philippinarum exposed to sediment extracts Полный текст
2018
Lin, Yufei | Liu, Qunqun | Meng, Fanping | Lin, Yichen | Du, Yongxiang
To evaluate the integrated toxicity of metals in sediments of Jiaozhou Bay, we exposed clam (Ruditapes philippinarum) to sediments extracts obtained using of sediment extraction with deionised water adjusted to pH 4 which simulated the weak acidity in the digestive juice of clams and tested the selected biomarkers responses in clams for exposure over 15 days. At the same time, the contents of metals in sediments were assessed with method of the mean sediment quality guideline quotient (SQG-Q). The integrated biomarker response version 2 (IBRv2) was used to assess the integrated toxicity induced by metals in sediment extracts based on biomarkers response in clams: the results demonstrated that site S7 located in the mouth of Nanxin'an River show higher IBRv2 values compared to the other sites. The IBRv2 values exhibited the good consistency with SQG-Q values.
Показать больше [+] Меньше [-]Influence of land-based Kaliningrad (Primorsky) amber mining on coastal zone Полный текст
2018
Krek, Alexander | Ulyanova, Marina | Koschavets, Svetlana
In this paper, we report on the pollution in the coastal zone of the South-Eastern Baltic Sea (Russian coast). It was studied through a range of methods, including analyses potential water quality indicators (WQIs) and potentially harmful elements (PHEs). A contamination factor and modified degree of contamination were used for describing the contamination of the sediments by toxic substances. Special attention was paid to activity of the Kaliningrad Amber Combine (KAC), the biggest world amber mining company, located onshore close to the coastal zone (Kaliningrad Region). The amber extraction contribution to the ecological state of the coastal zone was estimated. Contamination of the quarry by metals (Cr, Co, Ni, Cu, Pb, Zn) was comparable with contamination of abrasion bench. The pollution of the western coastal zone of the Sambia Peninsula is caused both by land-based anthropogenic developments (including KAC) and natural processes (coastal abrasion).
Показать больше [+] Меньше [-]High level of tris-(2,3-dibromopropyl) isocyanurate (TBC) and hexabromocyclododecanes (HBCDs) in sediments from the intertidal zone of New River Estuary—a polluted and degraded wetland Полный текст
2018
Zhang, Yu | Zheng, Minggang | Wang, Ling | Lou, Yinghua | Shi, Lei | Ke, Runhui | Wang, Bingui
The levels and distribution of tris-(2,3-dibromopropyl) isocyanurate (TBC) and hexabromocyclododecanes (HBCDs) in sediments in the intertidal zone of the New River Estuary were investigated. The concentration of TBC ranged from 2.78 to 35.1 ng·g−1dw, and the concentration of total HBCDs ranged from 10.3 to 43.5 ng·g−1dw. The composition of the three HBCD isomers, α-, β-, and γ-HBCD, was 6.23%, 8.00% and 85.8%, respectively. Moreover, the mass inventory of TBC, α-, β-, γ-HBCD, and total HBCDs in sediments were estimated to be about 1465.49, 124.64, 154.98, 1707.54, 1987.16 kg, respectively. Compared to previous studies, the concentrations of TBC and HBCDs in the intertidal zone of the New River Estuary were relatively high. Therefore, more concern of the potential public health and environmental risks of TBC and HBCDs is necessary.
Показать больше [+] Меньше [-]Comparative analysis of trace element accumulation in seagrasses Posidonia oceanica and Cymodocea nodosa: Biomonitoring applications and legislative issues Полный текст
2018
Bonanno, Giuseppe | Borg, Joseph A.
This study aimed to compare the bioaccumulation patterns and translocation of trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) from the environment in the seagrasses Posidonia oceanica and Cymodocea nodosa. Results showed that P. oceanica has a higher capacity of accumulation. P. oceanica and C. nodosa accumulate mainly in roots and leaves, the main organs acting as potential bioindicators. No significant correlation was found between water and both seagrasses. In turn, P. oceanica and C. nodosa were correlated, to a different extent, with As, Cd, Cu, Ni and Zn in sediments. This study showed also that current European regulations do not provide an exhaustive set of legal concentration limits of trace elements in marine water and sediments. Seagrasses P. oceanica and C. nodosa can act as effective bioindicators of trace elements only if quality limits are set for the most toxic elements present in marine ecosystems.
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