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Distribution, enrichment and sources of thallium in the surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea 全文
2015
Zhuang, Wen | Gao, Xuelu
The concentrations of thallium (Tl) in the surface sediments of the southwestern coastal Laizhou Bay and the rivers it connects were determined. In riverine sediments, the Tl concentrations ranged from 0.34 to 0.76μgg−1 in summer; in autumn, the corresponding data were 0.35–1.08μgg−1. In marine sediments, the Tl concentrations ranged from 0.36 to 0.58μgg−1 in summer; and from 0.30 to 0.56μgg−1 in autumn. The grain size, Al and Fe oxides were major factors affecting Tl distribution. Tl in the surface sediments of the studied area was mainly from the natural input with the non-natural input as a subsidiary source. The low concentrations of Tl made it hard to cause potential negative environmental effects in this area.
显示更多 [+] 显示较少 [-]Biodegradation of phthalate acid esters by different marine microalgal species 全文
2015
Gao, Jing | Chi, Jie
Biodegradation of diethyl phthalate (DEP) and di-n-butyl phthalate (DBP) by three marine algae was investigated. When they were coexistent, DBP was degraded more quickly than DEP. The first-order biodegradation rate constants of DBP in the algal solutions were in the order of Cylindrotheca closterium (0.0169h−1)>Dunaliella salina (0.0035h−1) and Chaetoceros muelleri (0.0034h−1). When singly existed, DEP was degraded more quickly than in a mixture with DBP, indicating that DBP had inhibitory effect on the biodegradation of DEP. Moreover, the degradation trends of DEP and DBP in both extra- and intracellular crude extracts were similar to those in algal solutions. At the end, DEP was largely in water phase, whereas DBP remained in both water phase and algal phase. It can be concluded that biodegradation of DEP was mainly by algal extracellular enzymes, and both extra- and intracellular enzymes played key roles in the degradation of DBP.
显示更多 [+] 显示较少 [-]The management in response to marine oil spill from ships in China: A systematic review 全文
2015
Xiong, Shangao | Long, Hualou | Tang, Guoping | Wan, Jun | Li, Hongyuan
Historical trends about marine ship-source oil spill incidents from 1990 to 2010 in China were analyzed, and it provided an overview of the status quo of China’s management in response to marine oil spill from ships. The Chinese government has issued a series of laws on marine environmental protection since 1982, and promulgated many regulations to prevent and tackle ship-source oil spill. At present, the oil spill emergency response system established in China has five levels: the national level, sea level, provincial level, port level, and ship level. China has demonstrated its ability to control and remove small-scale oil spill from ships in port area and near-shore coastal waters, and also paid attention to related research and development projects. Although China has made significant progress in managing shipping oil spill, challenges still exist, including strengthening oil spill emergency cooperation, enhancing China’s response capability, and improving relevant research and development projects.
显示更多 [+] 显示较少 [-]Antifouling assessments on biogenic nanoparticles: A field study from polluted offshore platform 全文
2015
Krishnan, Muthukumar | Sivanandham, Vignesh | Hans-Uwe, Dahms | Murugaiah, Santhosh Gokul | Seeni, Palanichamy | Gopalan, Subramanian | Rathinam, Arthur James
Turbinaria ornata mediated silver nanoparticles (TOAg-NPs) were evaluated for antibacterial activity against 15 biofilm forming bacterial isolates. A field study in natural seawater for 60days showed antifouling activity of TOAg-NPs on stainless steel coupons (SS-304) coated with Apcomin zinc chrome (AZC) primer. Though TOAg-NPs showed broad spectrum of antibacterial activity, the maximum zone of inhibition was with Escherichia coli (71.9%) and a minimum with Micrococcus sp. (40%) due to the EPS secretion from Gram-positive bacteria. Compared to control coupons (18.9 [×103], 67.0 [×103], 13.5 [×104] and 24.7 [×104]CFU/cm2), experimental biocide coupons (71.0 [×102], 32.0 [×103], 82.0 [×103] and 11.3 [×104]CFU/cm2) displayed lesser bacterial population density. Toxicity studies revealed 100% mortality for Balanus amphitrite larvae at 250μgml−1 concentration within 24h, while 56.6% recorded for Artemia marina at the same concentration indicating less toxicity to non target species. It proved that AZC+TOAg-NPs prevent biofouling by its Ag-NS affinity and antimicrobial effectivity.
显示更多 [+] 显示较少 [-]Debris ingestion by the Antillean Manatee (Trichechus manatus manatus) 全文
2015
Attademo, Fernanda Loffler Niemeyer | Balensiefer, Deisi Cristiane | Freire, Augusto Carlos da Bôaviagem | de Sousa, Glaucia Pereira | da Cunha, Fábio Adonis Gouveia Carneiro | Luna, Fábia de Oliveira
The Antillean manatee inhabits coastal regions of North and Northeastern Brazil and currently is considered an endangered species in the country. Aiming to gather information for the development of public policies focusing on the conservation of manatees, the National Center for Research and Conservation of Aquatic Mammals of the Chico Mendes Institute for Biodiversity has been rescuing, rehabilitating and releasing these mammals since the 1980s. Over the last 36years, 40 manatees were released by the CMA/ICMBio and four of them were rescued again due to debris ingestion. Two of these manatees died and the other two were taken back into captivity for a new rehabilitation process. The four mammals had confirmed diagnosis of plastic debris ingestion. These findings demonstrate that the environment where the manatees live after being released had a significant amount of garbage which may hinder the success of the species conservation in Brazil.
显示更多 [+] 显示较少 [-]Metal Pollution in Coastal Sediments 全文
2015
Qian, Yu | Zhang, Weiguo | Yu, Lizhong | Feng, Huan
Coastal sediment is a vital habitat for aquatic and marine life in coastal ecosystem. However, urbanization and economic development in coastal areas have resulted in environmental problems globally. Due to coastal development such as new industrial facilities and commercial port expansion, anthropogenic metals are introduced to the adjacent areas. Therefore, metal pollution in coastal areas is one of the focused environmental concerns. Sediment quality in coastal zone reflects the long-term environmental status because it keeps a record of the development in the area. In this review paper, sediment metal concentrations in 52 selected sites worldwide are summarized for evaluation of the coastal environmental quality. The results from this study can be applied to science-based policy formulation and ecological restoration/rehabilitation practices in an integrated coastal zone environmental management.
显示更多 [+] 显示较少 [-]Environmental controls on the speciation and distribution of mercury in surface sediments of a tropical estuary, India 全文
2015
Chakraborty, Parthasarathi | Babu, P.V Raghunadh
Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream of the estuary were uncontaminated but the sediments from the middle of the estuary were contaminated by Hg. The concentrations of Hg became considerably less during the monsoon and post monsoon period. Total Hg concentrations and its speciation (at the middle of the estuary) were dependent on the salinity of the overlying water column. However, salinity had little or no effect on Hg association with organic phases in the sediments at downstream. Increasing pH of the overlying water column corresponded with an increase in the total Hg content in the sediments. Total organic carbon in the sediments played an important role in controlling Hg partitioning in the system. Uncomplexed Hg binding ligands were available in the sediments.
显示更多 [+] 显示较少 [-]Heavy metal pollution assessment in relation to sediment properties in the coastal sediments of the southern Caspian Sea 全文
2015
Bastami, Kazem Darvish | Neyestani, Mahmoud Reza | Shemirani, Farzaneh | Soltani, Farzaneh | Haghparast, Sarah | Akbari, Atefeh
This study aimed to evaluate major elements and heavy metal concentrations of Arsenic (As), Copper (Cu), Chromium (Cr), Cobalt (Co), Vanadium (V), Nickel (Ni), lead (Pb) and Zinc (Zn) in surface sediments of the southern Caspian Sea. Metal contents in the sediment were observed in the order of: V>Cr>Zn>Ni>Co>Cu>Pb>As. Correlations between elements showed that sediment TOM, grain size and chemical composition are the main factors that influence the distribution of heavy metals. According to the pollution load index (PLI), sediments from some sampling sites were polluted. Concentrations of Ni, As, Cr and Cu were higher than sediment quality guidelines at some sampling sites, implying potential adverse impacts of these metals.
显示更多 [+] 显示较少 [-]The impact of debris on marine life 全文
2015
Gall, S.C. | Thompson, R.C.
Marine debris is listed among the major perceived threats to biodiversity, and is cause for particular concern due to its abundance, durability and persistence in the marine environment. An extensive literature search reviewed the current state of knowledge on the effects of marine debris on marine organisms. 340 original publications reported encounters between organisms and marine debris and 693 species. Plastic debris accounted for 92% of encounters between debris and individuals. Numerous direct and indirect consequences were recorded, with the potential for sublethal effects of ingestion an area of considerable uncertainty and concern. Comparison to the IUCN Red List highlighted that at least 17% of species affected by entanglement and ingestion were listed as threatened or near threatened. Hence where marine debris combines with other anthropogenic stressors it may affect populations, trophic interactions and assemblages.
显示更多 [+] 显示较少 [-]Biodiversity and degradation potential of oil-degrading bacteria isolated from deep-sea sediments of South Mid-Atlantic Ridge 全文
2015
Gao, Xiangxing | Gao, Wei | Cui, Zhisong | Han, Bin | Yang, Peihua | Sun, Chengjun | Zheng, Li
The indigenous oil-degrading bacterial consortia MARA and MARB were enriched from the deep-sea sediments of South Mid-Atlantic Ridge (MAR) with crude oil as sole carbon and energy sources. Biodiversity and community analyses showed that members of α-Proteobacteria were the key players in consortium MARA, whereas those of γ-Proteobacteria were the key players in consortium MARB, which were studied by MiSeq sequencing method. Gravimetric method estimated the oil degradation rates of MARA and MARB to be 63.4% and 85.8%, respectively, after 20d. Eleven cultivable oil degraders with different morphologies were isolated. These strains were identified as Alcanivorax, Bacillus, Dietzia, Erythrobacter, Marinobacter, Nitratireductor, and Oceanicola based on 16S rRNA gene sequences. Three strains belonging to Dietzia exhibited the highest oil degradation capability. Results indicated that the intrinsic biodegradation capacity of oil contaminants by indigenous microbial communities exists in South MAR sediments.
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