خيارات البحث
النتائج 2221 - 2230 من 8,010
Essential and non-essential heavy metal levels in key organs of winter flounder (Pseudopleuronectes americanus) and their potential impact on body condition النص الكامل
2021
Foley, M. | Askin, N. | Belanger, M.P. | Wittnich, C.
This study explored whether winter flounder, a benthic species, are potentially exposed to contaminants such as heavy metals released from the sediment of the Bay of Fundy/Gulf of Maine, both critical habitats identified to have increases in heavy metal levels. Experimentally in fish, exposure to certain heavy metals resulted in reduced weight for length and structural abnormalities, but it is unknown if this occurs in wild fish. Winter flounder (n = 72), harvested between 2015 and 2018 from the aforementioned western Atlantic region of Canada/USA, had detectable levels of most heavy metals, with some exhibiting levels of concern (arsenic, cadmium, lead, selenium, zinc) in muscle, liver, and kidney. A 1.4% incidence of structural abnormalities was noted. When compared to 1980 regionally matched flounder data, the 2018 flounder had significantly reduced weight for length, exacerbated with age. Clearly winter flounder are affected by worsening heavy metal contaminant levels in this geographic area.
اظهر المزيد [+] اقل [-]Microplastic contamination in salt pans and commercial salts – A baseline study on the salt pans of Marakkanam and Parangipettai, Tamil Nadu, India النص الكامل
2021
Nithin, A | Sundaramanickam, A | Surya, P | Sathish, M. | Soundharapandiyan, B | Balachandar, K
We studied the abundance of microplastics from commercial table salts and table salts from salt pans at Marakkanam and Parangipettai, Tamil Nadu, India. Microplastic abundance in the salts collected from salt pans had a range of 3.67 ± 1.54 to 21.33 ± 1.53 nos./10 g of salt which were higher than the microplastics retrieved from the commercial salts which ranged from 4.67 ± 1.15 to 16.33 ± 1.53 nos./10 g of salt. All the microplastics retrieved were fibers which were secondary in origin. Black, red, blue, green, white, brown, and colorless microplastics were observed in the samples. FT-IR results showed that 4 types of polymers, namely, Nylon, Polypropylene (PP), Low Density Polyethylene (LDPE), and Polyethylene Terephthalate (PET) were present in the samples. Domestic and municipal wastewater discharges into the estuaries may contribute to microplastics in the table salts. Our study proves that table salts (processed and unprocessed) are prone to microplastic contamination.
اظهر المزيد [+] اقل [-]Microplastic contamination in edible sea salt from the largest salt-producing states of India النص الكامل
2021
Vidyasakar, A. | Krishnakumar, S. | Kumar, K Suresh | Neelavannan, K. | Anbalagan, S. | Kasilingam, K. | Srinivasalu, S. | Saravanan, P. | Kāmarāj, Es. | Magesh, N.S.
The presence of microplastics in all ecological and environmental conditions has been identified as a global problem. This article aimed to study edible salt-associated microplastics from the major salt-producing states of India. The crystal and powder salt from Tamil Nadu and Gujarat (five samples of powder salt and three samples of crystal salt from each state) were collected and analyzed for their microplastic content. The total microplastic content in the salts ranged from 46 to 115 particles per 200 g in Gujarat salt and 23 to 101 particles per 200 g in Tamil Nadu salt. The microplastics are dominated by red and blue color fibrous-shaped materials. The most common microplastics identified in the edible salts were polyethylene, polyester, and polyvinyl chloride derived from marine and salt-processing units.
اظهر المزيد [+] اقل [-]Marine debris in Malaysia: A review on the pollution intensity and mitigating measures النص الكامل
2021
Fauziah, Shahul Hamid | Rizman-Idid, Mohammed | Cheah, Wee | Loh, Kar-Hoe | Sharma, Sahadev | M.R, NoorMaiza | Bordt, Michael | Praphotjanaporn, Teerapong | Azizan Abu Samah, | Sabaruddin, Johan Shamsuddin bin | George, Mary
The launch of Roadmap towards Zero Single-use Plastics in 2018 demands baseline data on the management of marine debris in Malaysia. In 2021, Malaysia is placed 28th top plastic polluter in the world with plastic consumption at 56 kg/capita/year, therefore data on mismanaged plastic is imperative. This paper reviews the abundance and distribution of marine debris in selected Malaysian beaches over the last decade (2010–2020) and discusses issue on its management. Plastic debris on beaches in Malaysia, was reported to range from 64 items/m², to as high as 1930 items/m², contributing 30–45% of total waste collected. Plastics film was the most dominant, mainly originated from packaging materials. Therefore, appropriate action including improved marine waste management system is crucial to tackle the problem, together with effective governance mechanisms. Various suggestions were proposed based on the statistical-environmental data to reduce the occurrence of marine debris in the country.
اظهر المزيد [+] اقل [-]Sargassum blooms in the East China Sea and Yellow Sea: Formation and management النص الكامل
2021
Zhuang, Minmin | Liu, Jinlin | Ding, Xiaowei | He, Jianzong | Zhao, Shuang | Wu, Lingjuan | Gao, Song | Zhao, Chunyan | Liu, Dongyan | Zhang, Jianheng | He, Peimin
Large-scale Sargassum blooms, known as golden tides, have been occurring along the coast of the Yellow Sea in recent years, resulting in an enormous loss of Pyropia yezoensis production. To locate the source of the blooms, we performed large-scale spatio-temporal sampling in the South Yellow Sea, East China Sea, and Jeju Island, South Korea. Based on morphology and molecular traits, the attached and floating Sargassum samples collected from the three regions were all identified as Sargassum horneri, although slight differences were observed in morphology among samples. Genetic distance and automatic barcode gap discovery analysis revealed very low genetic diversity among the three regions. The 33 samples from 12 sites were divided into six haplotypes, and the samples from the ECS shared more haplotypes than samples from other two regions. Our results suggested that S. horneri in the ECS was responsible for the formation of blooms in the Yellow Sea.
اظهر المزيد [+] اقل [-]Plastic litter pollution along sandy beaches in Puerto Princesa, Palawan Island, Philippines النص الكامل
2021
Sajorne, Recca E. | Bacosa, Hernando P. | Cayabo, Genese Divine B. | Ardines, Lucio B. | Sumeldan, Joel D.C. | Omar, Jhonamie M. | Creencia, Lota A.
Marine plastic litter pollution has become an emerging threat to the Philippines, especially in Palawan. This study was conducted to investigate the macroplastic litter and determine the clean-coast index (CCI) of the residential and non-residential sites on the coasts of Puerto Princesa, Palawan. Plastic litters were sampled from 21 coastal barangays by delineating a 50-m-long transect line with three 4 m × 4 m quadrats. The litter sampled were counted and sorted into categories. The results showed that 17 sites were contaminated with plastic litters. In terms of residential and non-residential sites, the east coast has thrice as much plastic, 2.61 items/m² and 1.26 items/m² compared to west coast with only 1.57 items/m² and 0.14 items/m², respectively. The plastics sampled were predominantly fishing line (nylon), food packaging, and fragments. The calculated CCI revealed that 76% of the sites sampled were categorized as dirty and extremely dirty.
اظهر المزيد [+] اقل [-]Preliminary study of oxidative stress biomarkers and trace elements in North Sea Harbour Seals النص الكامل
2021
Gismondi, Eric | Daneels, Lucienne | Damseaux, France | Lehnert, Kristina | Siebert, Ursula | Dāsa, Kr̥shṇā
Preliminary study of oxidative stress biomarkers and trace elements in North Sea Harbour Seals النص الكامل
2021
Gismondi, Eric | Daneels, Lucienne | Damseaux, France | Lehnert, Kristina | Siebert, Ursula | Dāsa, Kr̥shṇā
This preliminary study investigated the potential correlations between trace elements (mercury, zinc, cadmium, copper, selenium, lead, nickel, chromium, lithium and vanadium) concentrations, measured in red blood cells, and oxidative stress biomarkers (total thiols, total glutathione, total and selenium-dependent glutathione peroxidases, triglycerides, malondialdehyde) assessed in the respective serum, in males and females P. vitulina, sampled in the Wadden Sea in spring and autumn 2015.Only concentrations of total mercury and zinc showed significant differences by sex, and only lipid peroxidation was different by season. Moreover, significant positive and negative correlations were observed between biomarkers (triglycerides, thiols, malondialdehyde, glutathione) and trace element concentrations (copper, lead, mercury, nickel, zinc). These findings suggest that the studied biomarkers could be useful for the assessment of oxidative stress in harbour seals exposed to trace elements, but further research with larger sample sizes is needed to better understand their specific associations.
اظهر المزيد [+] اقل [-]Preliminary study of oxidative stress biomarkers and trace elements in North Sea Harbour Seals النص الكامل
2021
Gismondi, Eric | Daneels, Lucienne | Damseaux, France | Lehnert, Kristina | Siebert, Ursula | Das, Krishna | FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège
peer reviewed | This preliminary study investigated the potential correlations between trace elements (mercury, zinc, cadmium, copper, selenium, lead, nickel, chromium, lithium and vanadium) concentrations, measured in red blood cells, and oxidative stress biomarkers (total thiols, total glutathione, total and selenium-dependent glutathione peroxidases, triglycerides, malondialdehyde) assessed in the respective serum, in males and females P. vitulina, sampled in the Wadden Sea in spring and autumn 2015. Only concentrations of total mercury and zinc showed significant differences by sex, and only lipid peroxidation was different by season. Moreover, significant positive and negative correlations were observed between biomarkers (triglycerides, thiols, malondialdehyde, glutathione) and trace element concentrations (copper, lead, mercury, nickel, zinc). These findings suggest that the studied biomarkers could be useful for the assessment of oxidative stress in harbour seals exposed to trace elements, but further research with larger sample sizes is needed to better understand their specific associations. | 14. Life below water
اظهر المزيد [+] اقل [-]Preparation of Industrial Noise Mapping and Improvement of Environmental Quality النص الكامل
2021
Bozkurt, Tarık Serhat
Environmental noise control is necessary for human health and auditory comfort conditions. In this respect, it is required that industrial noise should be kept under control and healthy living spaces should be obtained in residential areas. This paper aims to explain industrial noise control at urban and building scales. In this study, the strategic noise mapping process related to industrial activities in a line with the Environmental Noise Directive (END) was clarified. Besides this, what type of factors are effective in the industrial noise mapping process were defined, and important basic parameters, which are essential in the industrial noise mapping, were detailed. The preparation of the industrial noise mapping process was explained in detail. It was mentioned that the regions exposed to excessive noise should be defined according to the strategic noise map and improvement plans should be performed. Improvement methods that reduce excessive noise in living spaces are clarified and it was explained how the improvement of environmental quality can be acquired. In this regard, this paper gives information on industrial noise mapping and industrial noise control at the urban scale.
اظهر المزيد [+] اقل [-]Spatial distribution and risk assessment of heavy metals pollution in soils of marine origin in central Saudi Arabia النص الكامل
2021
Alharbi, Talal | El-Sorogy, Abdelbaset S.
The present work aimed to evaluate the sources and ecological risks of heavy metal (HM) contamination in the soils of marine origin in central Saudi Arabia. HM concentrations were determined in 30 soil samples in October 2020, from Al Uyaynah–Al Jubailah region and their averages were in the following order: Al > Fe > Zn > Cr > Pb > Ni > As > Cu > Se > Cd > Hg > Sb. Average values of Zn, Ni, Co, Cr, and Cu in the investigated soils were less than averages of the continental crust, worldwide soils, and European soils, in contrast to the average values of As, Hg, Cd, and Se which were greater than the continental crust and worldwide soils. Enrichment factor, contamination factor, and degree of contamination revealed minor enriched and moderate contamination factors with As, Se, Hg, and Pb. Potential ecological risk index indicated that 93.33% of the soil samples fell under no-to-low risk, whereas 6.67% were categorized as moderate risk. Multivariate statistical analyses determined natural processes for Pb, Al, Cr, Sb, Zn, Fe, and Ni, while anthropogenic processes for As, Hg, and Se, mainly attributed to the chemicals used in agricultural applications and P fertilizers.
اظهر المزيد [+] اقل [-]Dynamic Energy Budget model suggests feeding constraints and physiological stress in black-lip pearl oysters, 5 years post mass-mortality event النص الكامل
2021
Monaco, Cristián J. | Sangare, Nathanael | Le Moullac, Gilles | Basset, Caline | Belliard, Corinne | Mizuno, Keiichi | Smith, Diane L. | Lo-Yat, Alain
Dynamic Energy Budget model suggests feeding constraints and physiological stress in black-lip pearl oysters, 5 years post mass-mortality event النص الكامل
2021
Monaco, Cristián J. | Sangare, Nathanael | Le Moullac, Gilles | Basset, Caline | Belliard, Corinne | Mizuno, Keiichi | Smith, Diane L. | Lo-Yat, Alain
Mass-mortality events of marine species can disturb the structure of communities. While identifying the causes of mass-mortality events is crucial for implementing recovery strategies, monitoring is challenging in remote locations. Black-lip pearl oysters (Pinctada margaritifera) are farmed for producing black pearls within remote atolls of French Polynesia. Previous mass-mortality events have resulted in the collapse of oysters and other species; however, the causes and conditions that favour recovery are unclear. We investigated the potential for oyster population recovery 5 years after a mortality event at Takaroa Atoll (Tuamotu Archipelago). Temperature, food availability (total chlorophyll-a), growth and reproduction were monitored. Growth was also simulated using a Dynamic Energy Budget model. Despite favourable conditions, reduced growth and reproduction signalled an energetic deficit. The model overpredicted growth, and supported the hypotheses that individuals are unable to profit from the phytoplankton available and maintenance costs are high in Takaroa, ultimately explaining their poor physiological condition.
اظهر المزيد [+] اقل [-]Dynamic Energy Budget model suggests feeding constraints and physiological stress in black-lip pearl oysters, 5 years post mass-mortality event النص الكامل
2021
Monaco, Cristian | Sangare, Nathanael | Le Moullac, Gilles | Basset, Caline | Belliard, Corinne | Mizuno, Keiichi | Smith, Diane L. | Lo-yat, Alain
Mass-mortality events of marine species can disturb the structure of communities. While identifying the causes of mass-mortality events is crucial for implementing recovery strategies, monitoring is challenging in remote locations. Black-lip pearl oysters (Pinctada margaritifera) are farmed for producing black pearls within remote atolls of French Polynesia. Previous mass-mortality events have resulted in the collapse of oysters and other species; however, the causes and conditions that favour recovery are unclear. We investigated the potential for oyster population recovery 5 years after a mortality event at Takaroa Atoll (Tuamotu Archipelago). Temperature, food availability (total chlorophyll-a), growth and reproduction were monitored. Growth was also simulated using a Dynamic Energy Budget model. Despite favourable conditions, reduced growth and reproduction signalled an energetic deficit. The model overpredicted growth, and supported the hypotheses that individuals are unable to profit from the phytoplankton available and maintenance costs are high in Takaroa, ultimately explaining their poor physiological condition
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