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Результаты 1971-1980 из 4,896
Is recreational boating a potential vector for non-indigenous peracarid crustaceans in the Mediterranean Sea? A combined biological and social approach
2019
Martínez-Laiz, G. | Ulman, A. | Ros, M. | Marchini, A.
Shipping is understood to be a major vector for the introduction and spread of marine non-indigenous species (NIS). However, recreational boating is still unregulated and its influence as vector has not yet been assessed for the Mediterranean Sea, which is the second most popular recreational boating destination worldwide. This is the first large-scale study to examine this by a combined biological (analyzing hull and marina fouling) and social approach (boaters surveys on maintenance habits, travel patterns and awareness), focused on peracarid crustaceans. A surprisingly high number of NIS were found on vessels cruising Mediterranean waters, and species compositions suggest an exchange between marina and vessel assemblages. This means recreational boating presents a risk for NIS spread which should warrant regulation. Results also implied that regionally coordinated management should be supported by effective local-scale-based management in the Mediterranean, which could improve upon with targeted environmental education to solve lack of awareness.
Показать больше [+] Меньше [-]Evaluation of macroalgae and amphipods as bioindicators of petroleum hydrocarbons input into the marine environment
2019
Lourenço, Rafael André | Magalhães, Caio Augusto | Taniguchi, Satie | Siqueira, Silvana Gomes Leite | Jacobucci, Giuliano Buzá | Leite, Fosca Pedini Pereira | Bícego, Márcia Caruso
The brown alga Sargassum furcatum and three families of amphipods (Ampithoidae, Caprellidae and Hyalidae) associated to that algae were evaluated as bioindicators of petroleum hydrocarbons input into the marine environment of São Sebastião Channel, in southeastern region of Brazil. The n-alkanes pattern were mainly associated with the natural composition of the macroalgae and amphipods, although some indicatives of petroleum hydrocarbons such as unresolved complex mixture and the no predominance of odd over even n-alkanes have been observed in some samples. Total PAHs ranged from 33.4 to 2010 ng g⁻¹ dry weight with the predominance of low molecular weight PAHs, mostly of naphthalene and alkyl-naphthalenes, which also suggested petroleum input. Even in low concentration, Sargassum furcatum and amphipods species studied seems to be good indicators of the introduction of petroleum hydrocarbons.
Показать больше [+] Меньше [-]A trial of in situ and static measurements of levels of radioactive cesium 137 on shallow rugged reefs lying close to the coastline of Fukushima
2019
Suzuki, Fumie | Ohashi, Hideo | Shibata, Hiromi | Nogami, Ken-ichi | Arakawa, Hisayuki | Shiotani, Nobuhiro
With the use of an in situ and static method for gamma-ray measurements, levels of radioactive cesium 137 on shallow rugged reefs which lie between 37.3° N and 37.4° N, from the coastline of Fukushima to 141.06° E, at a depth of around 10 m were surveyed for the first time from May 2016 to December 2017. To confirm the contact between the detector and a surface of rock, we used a fact that potassium containing minerals are abundant and uniformly distributed in the area, and thus the strength of the photoelectric peak of natural radioactive potassium 40 is nearly constant over the area. We have found that the levels of radioactive cesium 137 varied from point to point within a range from 1 × 10⁴ Bq/m² to 6 × 10⁴ Bq/m².
Показать больше [+] Меньше [-]Arsenic in Drinking Water : Is 10 μg/L a Safe Limit?
2019
Ahmad, Arslan | Bhattacharya, Prosun
Arsenic (As) is a naturally occurring element in the Earth’s crust. Both anthropogenic and natural processes can release As into sources for drinking water supply. A substantial epidemiological evidence is available to support that the chronic exposure to high concentrations in drinking water (> 10 μg/L) is associated with several detrimental effects on human health including skin lesions [1] and cancer of the lung [2], bladder [3], kidney [4], and liver [4]. Furthermore, dermatological, developmental, neurological [5], respiratory [6], cardiovascular [7], immunological [8], and endocrine effects [9] as a result of chronic exposure to high As concentrations have been reported. However, there remains considerable uncertainty on the chronic risks due to As exposure at low concentrations (< 10 μg/L) and the shape of the dose-response relationship [10, 11]. It is therefore crucial to question whether the 10 μg/L limit ensures protection of human health from the adverse health effects of As.
Показать больше [+] Меньше [-]A novel GIS-based tool for predicting coastal litter accumulation and optimising coastal cleanup actions
2019
Haarr, Marthe Larsen | Westerveld, Levi | Fabres, Joan | Iversen, Kriss Rokkan | Busch, Kjersti Eline Tønnessen
Effective site selection is a key component of maximising debris removal during coastal cleanup actions. We tested a GIS-based predictive model to identify marine litter hotspots in Lofoten, Norway based on shoreline gradient and shape. Litter density was recorded at 27 randomly selected locations with 5 transects sampled in each. Shoreline gradient was a limiting factor to litter accumulation when >35%. The curvature of the coastline correlated differently with litter density at different spatial scales. The greatest litter concentrations were in small coves located on larger headlands. A parsimonious model scoring sites on a scale of 1–5 based on shoreline slope and shape had the highest validation success. Sites unlikely to have high litter concentrations were successfully identified and could be avoided. The accuracy of hotspot identifications was more variable, and presumably more parameters influencing litter deposition, such as shoreline aspect relative to prevailing winds, should be incorporated.
Показать больше [+] Меньше [-]To clean or not to clean? A critical review of beach cleaning methods and impacts
2019
Zielinski, Seweryn | Botero, Camilo M. | Yanes, Andrea
Cleaning is a fundamental concern of beach managers in many destinations as well as an important requirement in beach quality awards. However, it has been largely neglected in the literature. This paper provides an overview of empirical studies on beach cleaning and analyzes cleaning-related requirements of 11 beach awards that generate controversy in the literature. This study comments on key aspects of beach cleaning, resolves various misconceptions, and provides new perspectives by integrating related topics drawn from a wide range of literature. The arguments based on both the ecological and tourism managerial perspectives are presented, indicating the gaps and proposing research solutions. The paper calls for empirical studies with regard to the efficiency of different cleaning approaches on beaches with varying levels of use intensity and for methodological designs that separate the impacts of mechanical grooming from those of trampling, dune destruction, shore armoring, artificial lighting, among others.
Показать больше [+] Меньше [-]Seawater quality criteria derivation and ecological risk assessment for oil pollution in China
2019
Zhenguang, Yan | Pan, Jinfen | Gao, Fu | An, Zhe | Liu, Huifang | Huang, Yi | Wang, Xiaobing
The establishment of water quality criteria (WQC) for oil pollutants is the basis for ecological risk assessment of marine oil pollution. Ecotoxicity data of oil pollutants to marine organisms in China were collected and toxicity test of oil to nine Chinese marine organisms were performed. Based on the WQC guidelines of the United States, the sea WQC of oil pollutants in China were studied. Then, the ecological risk of oil in 7 sea areas of China was assessed. Results showed that the long-term and short-term criteria of oil pollutants in China are 7.3 μg/L and 36 μg/L, respectively. Except for Qinhuangdao and Xiamen sea areas, the highest oil concentration in the other five sea areas exceeded the long-term WQC by >10 times, and the highest oil concentration in the Pearl River Estuary exceeded the long-term WQC by >100 times, indicating serious ecological risk.
Показать больше [+] Меньше [-]Stable isotopes and geochemical indicators in marine sediments as proxies for anthropogenic impact: A baseline for coastal environments of central Chile (33°S)
2019
Pastene, Marion | Quiroga, Eduardo | Hurtado, Carlos Felipe
Stable isotopes and geochemical proxies (TOC/TN and Chla/TOC) in sediments can be used to distinguish organic matter sources (anthropogenic, terrestrial, or marine). This study aims to characterize organic matter (OM) in superficial sediments from three sectors of central Chile (33°S) that are highly influenced by urban and industrial development. Our results show that a substantial fraction of these OM in Quintero Bay is anthropogenic, from industrial and domestic wastewater sources. In contrast, a mixture of terrestrial and anthropogenic OM dominates the isotopic signal of surface sediments from Concón, derived from non-point industrial and agriculture sources associated with the Aconcagua River basin, while Ritoque exhibited a mixture of different OM sources. However, deposition of allochthonous OM in our study area depends on coastal topography, which influences the local currents and well-ventilated waters, promoting the dispersion and assimilation of OM and thus providing an environment with a high capacity for natural remediation.
Показать больше [+] Меньше [-]Heavy metal contamination status in soil-plant system in the Upper Mersey Estuarine Floodplain, Northwest England
2019
Enya, Osim | Lin, Chuxia | Qin, Junhao
Globally, soil contamination by heavy metals is common in estuarine floodplains. A study was conducted to assess heavy metal contamination in the soil-plant system in Mersey estuarine floodplain, North West England. Representative composite soil samples and plant samples were collected from nine identified land use types across the study area. Various fraction of heavy metals in soils and plant tissue-borne heavy metals were determined. The results show that the study area has elevated concentrations of As, Cr, Cu, Pb and Zn. Heavy metal concentration in soils was generally higher in the lowlying areas than in the upland portions. There was a trend that concentration of heavy metals increased with increasing depth due to de-industrialisation in the upper catchment. The soil contamination resulted in elevated concentration of heavy metals in the grazed plants, which could pose a risk to wild animals, grazing animals and people who consume the grazing animal meat.
Показать больше [+] Меньше [-]Inhabiting the technosphere: The encroachment of anthropogenic marine litter in Neotropical mangrove forests and its use as habitat by macrobenthic biota
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.
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