خيارات البحث
النتائج 1771 - 1780 من 4,936
Non-indigenous macrophytes in Adriatic ports and transitional waters: Trends, taxonomy, introduction vectors, pathways and management النص الكامل
2019
Orlando Bonaca, Martina | Lipej, Lovrenc | Bonanno, Giuseppe
The Adriatic Sea is considered as a hotspot of marine biodiversity but, due to intense human activities (e.g. maritime transport, mariculture), it is also a recipient area of non-indigenous species (NIS). This study analyzed the scientific literature on non-indigenous macrophytes (NIM) recorded in ports, marinas and transitional waters (TWs) of the Adriatic Sea, in the period 1987–2018. The results show that 51 out of 118 Mediterranean NIM are found in Adriatic ports and TWs. The Venice Lagoon is the main Adriatic recipient area of NIM. Mariculture is the main vector of introduction, whereas the principal pathways of NIM dispersal are shipping and shellfish transfer. The largest group of NIM is of temperate northern Pacific origin. This study corroborated the fact that ports and TWs act as dispersal hubs and invasion hotspots. The importance of early detection of NIM at such sites should be considered in any environmental management strategy.
اظهر المزيد [+] اقل [-]Marine litter and microplastic pollution on mangrove soils of the Ciénaga Grande de Santa Marta, Colombian Caribbean النص الكامل
2019
Garcés-Ordóñez, Ostin | Castillo-Olaya, Victoria A. | Granados-Briceño, Andrés F. | Blandón García, Lina M. | Espinosa Díaz, Luisa F.
Marine litter pollution has become a complex global problem, because of the negative ecological and socioeconomic impacts as well as the human health risks that it represents. In Colombia, mangroves are affected by inadequate solid waste management, which results in litter accumulation. Additionally, the information related to this problem is limited avoiding the development of prevention and reduction strategies. For the first time, pollution by marine litter and microplastics were evaluated in mangrove soils of the Ciénaga Grande de Santa Marta, where 540 ± 137 and 31 ± 23 items/ha of marine litter were determined in mangroves near and away from populated centers respectively. Plastics represented between 73 and 96% of litter, and microplastic quantity oscillated between 31 and 2,863 items/kg finding the highest concentrations in mangroves near to the population. This study contributes to the knowledge of the marine litter problem in mangroves of the Colombian Caribbean, becoming a help for their conservation.
اظهر المزيد [+] اقل [-]Inhabiting the technosphere: The encroachment of anthropogenic marine litter in Neotropical mangrove forests and its use as habitat by macrobenthic biota النص الكامل
2019
Riascos, José M. | Valencia, Natasha | Peña, Enrique J. | Cantera, Jaime R.
Coastal urbanization is leading to the accumulation of anthropogenic litter. Understanding the distribution and habitat use of litter by marine biota is important to predict how organisms will respond to anthropogenic changes. We assessed the density, distribution and composition of surface macro-litter (SML) in mangrove forests in Buenaventura (Colombia) and analysed how these microhabitats are used by marine biota. SML density ranged from 2 to 314 g m⁻² (0.22 to 35.5 items m⁻²), implying that mangrove forests surrounding Buenaventura city are among the most polluted coastal areas in the World. Biological assemblages colonizing SML differed according to position on the forest and litter type. The encroachment of SML in mangrove forest enables a seemingly transient colonization of resident and immigrant biota from intertidal rocky shores and subtidal hard bottoms. The successful colonization of SML poses questions regarding the potential for plastics or their leaching chemicals to transfer through food webs.
اظهر المزيد [+] اقل [-]Carbon and nitrogen stable isotope signatures linked to anthropogenic toxic substances pollution in a highly industrialized area of South Korea النص الكامل
2019
Hong, Seongjin | Lee, Yeonjung | Yoon, Seo Joon | Lee, Junghyun | Kang, Sujin | Won, Eun-Ji | Hur, Jin | Khim, Jong Seong | Shin, Kyung-Hoon
Sources of organic matter in a polluted coastal embayment (Lake Sihwa) indicated that δ¹³C and δ¹⁵N of suspended particulate matter (SPM) and sediments could be distinguished by land-use type and surrounding activities. Specifically, low δ¹⁵N occurred in inland creeks near industrial complex, where severe contamination by persistent toxic substances (PTSs) is evidenced. To identify the sources of ¹⁵N-depleted organic matter and PTSs, the SPM and/or sediments were collected along ~8 km of the Singil Creek and in stormwater drainage pipes that carried pollutants to the creeks from upland areas. Results indicated that stormwater originating in industrial areas was the main source of low δ¹⁵N and elevated PTSs, which appeared to flow into stormwater drains with rainwater and eventually into the creeks at stormwater outfalls. To improve the water quality of inland creeks, it will be necessary to reduce the amount of untreated stormwater entering stormwater drainage system from industrial complex.
اظهر المزيد [+] اقل [-]Modeling the toxicity of dissolved crude oil exposures to characterize the sensitivity of cod (Gadus morhua) larvae and role of individual and unresolved hydrocarbons النص الكامل
2019
Hansen, Bjørn Henrik | Parkerton, Thomas | Nordtug, Trond | Størseth, Trond R. | Redman, Aaron
Modeling the toxicity of dissolved crude oil exposures to characterize the sensitivity of cod (Gadus morhua) larvae and role of individual and unresolved hydrocarbons النص الكامل
2019
Hansen, Bjørn Henrik | Parkerton, Thomas | Nordtug, Trond | Størseth, Trond R. | Redman, Aaron
Toxicity of weathered oil was investigated using Atlantic cod (Gadus morhua) larvae. A novel exposure system was applied to differentiate effects associated with dissolved and droplet oil with and without dispersant. After a 4-day exposure and subsequent 4-day recovery period, survival and growth were determined. Analytical data characterizing test oil composition included polyaromatic hydrocarbons (PAH) based on GC/MS and unresolved hydrocarbon classes obtained by two-dimensional chromatography coupled with flame ionization detection was used as input to an oil solubility model to calculate toxic units (TUs) of dissolved PAHs and whole oil, respectively. Critical target lipid body burdens derived from modeling characterizing the sensitivity of effect endpoints investigated were consistent across treatments and within the range previously reported for pelagic species. Individually measured PAHs captured only 3–11% of the TUs associated with the whole oil highlighting the limitations of traditional total PAH exposure metrics for expressing oil toxicity data.
اظهر المزيد [+] اقل [-]Modeling the toxicity of dissolved crude oil exposures to characterize the sensitivity of cod (Gadus morhua) larvae and role of individual and unresolved hydrocarbons النص الكامل
2019
Hansen, Bjørn Henrik | Parkerton, Thomas F. | Nordtug, Trond | Størseth, Trond Røvik | Redman, Aaron D.
Toxicity of weathered oil was investigated using Atlantic cod (Gadus morhua) larvae. A novel exposure system was applied to differentiate effects associated with dissolved and droplet oil with and without dispersant. After a 4-day exposure and subsequent 4-day recovery period, survival and growth were determined. Analytical data characterizing test oil composition included polyaromatic hydrocarbons (PAH) based on GC/MS and unresolved hydrocarbon classes obtained by two-dimensional chromatography coupled with flame ionization detection was used as input to an oil solubility model to calculate toxic units (TUs) of dissolved PAHs and whole oil, respectively. Critical target lipid body burdens derived from modeling characterizing the sensitivity of effect endpoints investigated were consistent across treatments and within the range previously reported for pelagic species. Individually measured PAHs captured only 3–11% of the TUs associated with the whole oil highlighting the limitations of traditional total PAH exposure metrics for expressing oil toxicity data. | acceptedVersion
اظهر المزيد [+] اقل [-]Plastic-derived contaminants in sediments from the coastal zone of the southern Baltic Sea النص الكامل
2019
Lubecki, Ludwik | Kowalewska, Grażyna
Plastics may leach out harmful chemicals, such as plastic additives and monomers, to the environment. This study focused on three intrinsic plastic-derived contaminants, viz. bis(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and styrene, based on surface (0–5 cm) sediment samples taken from transition areas located in the human-impacted coastal zone of the southern Baltic Sea. The concentrations of DEHP in the sediments from the Gulf of Gdańsk and the Szczecin Lagoon ranged from 38 to 228 ng/g d.w. and from 494 to 807 ng/g d.w., respectively. The levels of sedimentary BPA varied from <1 to 32 ng/g d.w., whereas styrene was not detected in any of the samples studied. Compared to worldwide data, the levels of plastic-derived contaminants in the sediments from the Gulf of Gdańsk and the Szczecin Lagoon were generally not high. However, according to sediment quality guidelines, some adverse environmental effects are probable.
اظهر المزيد [+] اقل [-]Different stories told by small and large microplastics in sediment - first report of microplastic concentrations in an urban recipient in Norway النص الكامل
2019
Haave, Marte | Lorenz, Claudia | Primpke, Sebastian | Gerdts, Gunnar
Different stories told by small and large microplastics in sediment - first report of microplastic concentrations in an urban recipient in Norway النص الكامل
2019
Haave, Marte | Lorenz, Claudia | Primpke, Sebastian | Gerdts, Gunnar
Microplastics (MP) in sediments from discharge sites for wastewater and deposition sites in deep regions in an urban fjord in Norway were extracted by density separation in a Microplastic Sediment Separator with ZnCl2. Particles (>11 μm) were identified using FTIR. Twenty different polymer types were identified, at concentrations from 12,000 to 200,000 particles kg−1 dw. Over 95% of the MP were smaller than 100 μm. High deposition of small MP agreed with known areas for organic deposition. Polyurethane acrylate resins dominated the small MP while polyamide fibers dominated the larger MP. Particles >500 μm showed different maximum concentrations and spatial distribution from the smaller particles. This study is the first to report concentration ranges of identified plastic particles from a Norwegian fjord, down to sizes below the limit of visual identification. The results provides a baseline for future comparison, and point at relevant sizes for environmental risk assessments.
اظهر المزيد [+] اقل [-]Different stories told by small and large microplastics in sediment - first report of microplastic concentrations in an urban recipient in Norway النص الكامل
2019
Haave, Marte | Lorenz, Claudia | Primpke, Sebastian | Gerdts, Gunnar
Microplastics (MP) in sediments from discharge sites for wastewater and deposition sites in deep regions in an urban fjord in Norway were extracted by density separation in a Microplastic Sediment Separator with ZnCl2. Particles (>11 μm) were identified using FTIR. Twenty different polymer types were identified, at concentrations from 12,000 to 200,000 particles kg−1 dw. Over 95% of the MP were smaller than 100 μm. High deposition of small MP agreed with known areas for organic deposition. Polyurethane acrylate resins dominated the small MP while polyamide fibers dominated the larger MP. Particles >500 μm showed different maximum concentrations and spatial distribution from the smaller particles. This study is the first to report concentration ranges of identified plastic particles from a Norwegian fjord, down to sizes below the limit of visual identification. The results provides a baseline for future comparison, and point at relevant sizes for environmental risk assessments.
اظهر المزيد [+] اقل [-]Depuration reduces microplastic content in wild and farmed mussels النص الكامل
2019
Birnstiel, Stéphanie | Soares-Gomes, Abilio | da Gama, Bernardo A.P.
Plastic pollution is a pervasive problem to marine life. This study aimed (1) to investigate levels of microplastic in wild and farmed mussels (Perna perna), and (2) to assess the effectiveness of depuration in reducing microplastics. Wild and farmed mussels were sampled from Guanabara Bay (Southwestern Atlantic). Four treatments were compared (N = 10 mussels/treatment): wild non-depurated mussels, wild depurated mussels, farmed non-depurated mussels, and farmed depurated mussels. Up to 31.2 ± 17.8 microplastics/mussel (≥0.45 μm) were detected (means ± SD), and microplastics were present in all 40 individuals analyzed. Nylon fibers were more abundant than polymethyl methacrylate (PMMA) fragments. Blue, transparent, and red nylon fibers were more abundant in both wild and farmed mussels. Although 93 h-depuration significantly reduced microplastics (ANOVA, p = 0.02) in both wild (46.79%) and farmed mussels (28.95%), differences between farmed and wild mussels were not significant (p > 0.05). Depuration was more effective in removing blue fibers. Our results highlight the importance of depuration in reducing microplastic pollution in seafood.
اظهر المزيد [+] اقل [-]Marine debris at nesting grounds used by the Northern Gulf of Mexico loggerhead recovery unit النص الكامل
2019
Garrison, Samantha R. | Fuentes, Mariana M.P.B.
Anthropogenic marine debris (AMD) can cause obstructions for nesting marine turtles and hatchlings, increase their exposure to toxicants, and potentially alter the incubating environment of clutches. Given the potential impacts of AMD on marine turtles, this study provides baseline information on the abundance and distribution of AMD at the ten highest density nesting beaches in Florida used by the Northern Gulf of Mexico Loggerhead Recovery Unit. Monitoring for AMD at nesting beaches was conducted in 2017 following protocols from the International Coastal Cleanup. AMD was present at all the nesting beaches, with the majority of AMD observed at the westernmost sites beginning with St. Joseph Peninsula State Park (363 AMD/km) with a gradual decrease of abundance to the easternmost site, Alligator Point (16 AMD/km). Plastic and foam items accounted for 92% (n = 13,566) of all AMD found.
اظهر المزيد [+] اقل [-]Remote sensing estimation of the biomass of floating Ulva prolifera and analysis of the main factors driving the interannual variability of the biomass in the Yellow Sea النص الكامل
2019
Xiao, Yanfang | Zhang, Jie | Cui, Tingwei | Gong, Jialong | Liu, Rongjie | Chen, Xiaoying | Liang, Xijian
Since 2007, green tide blooms with Ulva prolifera as the dominant species have occurred every summer in the Yellow Sea. Biomass is a critical parameter used to describe the severity of green tide blooms. In this study, we analyzed the relationships between several indices (normalized difference vegetation index (NDVI), floating algae index (FAI), ratio vegetation index (RVI), enhanced vegetation index (EVI), ocean surface algal bloom index (OSABI), Korea Ocean Satellite Center (KOSC) approach) and the biomass per unit area of Ulva prolifera by using the in situ measurements from a water tank experiment. EVI, NDVI, and FAI showed strong exponential relationships with Ulva prolifera biomass per unit area. In order to apply the relationships to satellite remote sensing data, the impacts of the atmosphere (different aerosol optical depth at 550 nm) and mixed pixels to the relationships were analyzed. The results show that atmosphere has little effect on the relationship between EVI and Ulva prolifera biomass per unit area with R2 = 0.94 and APD (the average percentage deviation) = 19.55% when EVI is calculated from Rrc (Rayleigh-corrected reflectance), and R2 = 0.95 and APD = 17.53% when EVI is calculated from Rtoa (top-of-atmosphere reflectance). Due to the low sensitivity to the atmosphere, the EVI relationship can be directly utilized in the top-of-atmosphere (TOA) reflectance without atmospheric correction. In addition, the EVI was slightly affected by mixed pixels with the APD only increased by ~10%. The EVI relationship was then applied to a long MODIS image time series to obtain the maximal total biomass of floating Ulva prolifera in the Yellow Sea from 2007 to 2016. The results showed that the maximum and minimum total biomass occurred in 2016 (~1.17 million tons) and 2012 (~0.074 million tons), respectively. The main factors that caused the inter-annual biomass variability were analyzed. The total amount of nutrients from Sheyang River which was the largest river on the northern coast of Jiangsu Province, and Porphyra cultivation in the Radial Sand Ridges of Jiangsu Province had both strong correlation with Ulva prolifera total biomass.
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