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Результаты 1631-1640 из 4,309
Concomitance of oligotrophy and low grazing pressure is essential for the resilience of Mediterranean subtidal forests Полный текст
2017
Piazzi, Luigi | Ceccherelli, Giulia
The study aimed at investigating factors influencing the recovery of the canopy seaweed Cystoseira brachycarpa. A manipulative experiment was done to test if in barren patches the recovery of Cystoseira I) is enhanced by the removal of the urchins, II) is prevented by eutrophication, III) depends on the time of patch clearance and IV) decreases with the distance from Cystoseira bed edge within the barren patch. The effects of the same factors on the structure of the macroalgal assemblage were also tested. Cystoseira recovered abundantly only in clearings where nutrients were not added and urchins were removed. Furthermore, Cystoseira recovered irrespectively of the time the patches were cleared and the distance from the canopy edge. This study showed that the lack of sea urchins at oligotrophic conditions was essential for Cystoseira brachycarpa recruitment, providing evidence that interacting constraints are involved in the recovery of Cystoseira beds.
Показать больше [+] Меньше [-]Green oysters occurring in an industrial harbor in Central Taiwan Полный текст
2017
Fang, Tien-Hsi | Dai, Shi-Yan
Green oysters were found within the Mailiao industrial harbor (MIH) located in Central Taiwan. The metal concentrations in seawater (dissolved and particulate phases), sediment and oyster samples collected within the MIH were analyzed to examine the green oysters. The dissolved and particulate metal concentrations ranged within 0.008–1.47μgl−1 and 0.97–799.2mgkg−1, respectively. The Cu concentration in seawater was dominated in the dissolved phase. In contrast, Cr, Pb and Zn in seawater were chiefly present in the particulate phase. The metal concentrations in sediment and oyster samples ranged within 0.02–148.4mgkg−1 and 0.18–1238mgkg−1 (dry W.), respectively. No anomalous values were found in the analyzed samples, except the Cu content in the oyster samples ranged within 274–1238mgkg−1. The relatively high bioconcentration factor of Cu in oyster and the longer exposure time induced the green oysters occurred within the MIH.
Показать больше [+] Меньше [-]Cross-reactivities of mammalian MAPKs antibodies in rotifer and copepod: Application in mechanistic studies in aquatic ecotoxicology Полный текст
2017
Kang, Hye-Min | Jeong, Chang-Bum | Lee, Young-Hwan | Cui, Yan-Hong | Kim, Duck-Hyun | Lee, Min-Chul | Kim, Hŭi-su | Han, Jeonghoon | Hwang, Dae-Sik | Lee, Su-Jae | Lee, Jae-seong
The mitogen-activated protein kinases (MAPKs) family is known to mediate various biological processes in response to diverse environmental pollutants. Although MAPKs are well characterized and studied in vertebrates, in invertebrates the cross-reactivities of MAPKs antibodies were not clearly known in response to environmental pollutants due to limited information of antibody epitopes with material resources for invertebrates. In this paper, we performed phylogenetic analysis of MAPKs genes in the marine rotifer Brachionus koreanus and the copepods Paracyclopina nana and Tigriopus japonicus. Also in rotifer and copepods, several studies of Western blot of MAPK signaling pathways were shown in response to environmental pollutants, including multi-walled carbon nanotubes (MWCNTs), water-accommodated fractions (WAFs) of crude oil, and microplastics. This paper will provide a better understanding of the underlying mechanistic scenario in terms of cross-reactivities of mammalian antibodies in rotifer and copepod.
Показать больше [+] Меньше [-]Molecular characterization of ABC transporters in marine ciliate, Euplotes crassus: Identification and response to cadmium and benzo[a]pyrene Полный текст
2017
Kim, Hokyun | Yim, Bora | Kim, Jisoo | Kim, Haeyeon | Lee, Young-Mi
ATP-binding cassette (ABC) transporters participate in transporting various substances, including xenobiotics, in or out of cells. However, their genetic information and function in ciliates remain still unclear. In this study, we sequenced and characterized two ABC transporter genes (EcABCB and EcABCC), and investigated the effect of cadmium (Cd) and benzo[a]pyrene (B[a]P) on their function and gene expression, using efflux assay and real-time reverse transcription-polymerase chain reaction (qRT-PCR), respectively, in the marine ciliate, Euplotes crassus. Sequencing analysis and efflux assay showed that EcABCB and EcABCC are typical ABC transporters, possessing conserved function. Exposure to Cd (≥5mg/L) and B[a]P (≥50.5μg/L) enhanced accumulation of a substrate. A significant increase in the expression of EcABCB and EcABC mRNA was observed at lower concentration in response to Cd and B[a]P. Our findings indicate that Cd and B[a]P could inhibit the efflux function of ABC transporters, leading to cellular toxicity in the ciliate.
Показать больше [+] Меньше [-]Characteristics of picoplankton abundances during a Thalassiosira diporocyclus bloom in the Taiwan Bank in late winter Полный текст
2017
Jiang, Xin | Li, Jiajun | Ke, Zhixin | Xiang, Chenhui | Tan, Yehui | Huang, Liangmin
To understand the variations of picoplankton (Prochlorococcus, Synechococcus, picoeukaryotes, and heterotrophic bacteria) abundances during diatom bloom, the distribution of picoplankton in the Taiwan Bank, South China Sea was investigated using flow cytometry during a Thalassiosira diporocyclus bloom in March 2016. The results indicated an abrupt abundance decrease for Prochlorococcus, Synechococcus, and picoeukaryotes within the bloom area while the abundance of heterotrophic bacteria showed no significant difference between the bloom and non-bloom areas. We found two sub-groups of heterotrophic bacteria: high- and low-nucleic acid content (HNA and LNA) bacteria with HNA dominated in the bloom area whereas LNA dominated in the non-bloom area. Among the picoplankton components, HNA represented the highest (61.1%) carbon biomass in the bloom area while picoeukaryotes represented the highest (37.6%) in the non-bloom area. Our findings implied that heterotrophic bacteria, especially HNA, played an essential role during the diatom bloom.
Показать больше [+] Меньше [-]Chlorination induced damage and recovery in marine diatoms: Assay by SYTOX® Green staining Полный текст
2017
Venkatnarayanan, Srinivas | Sriyutha Murthy, P. | Nancharaiah, Yarlagadda V. | Kirubagaran, Ramalingam | Venugopalan, Vayalam P.
Phytoplankton entrained into cooling water systems of coastal power stations are subjected to acute chemical stress due to biocides (chlorine) used for biofouling control. They are subsequently released into the environment, where they may survive/recover or succumb. Experiments were conducted to evaluate the susceptibility of a centric (Chaetoceros lorenzianus) and pennate (Navicula sp.) diatom to in-plant administered concentrations of chlorine (0.2–0.5mg/L, TRO). Viability of cells exposed to chlorine was assessed by SYTOX® Green fluorimetry and was compared with other conventional end points like total cell counts, chlorophyll a content and cellular autofluorescence. Results showed a concentration-dependant reduction in viability, chlorophyll a and autofluorescence. C. lorenzianus cells were more susceptible to chlorine compared to Navicula sp. SYTOX® Green staining appears to be a sensitive method to assess chlorine-induced damages. The data show that in-use levels of chlorination can potentially impact entrained organisms; however, they can recover when returned to coastal waters.
Показать больше [+] Меньше [-]Long-term monitoring study of beached seabirds shows that chronic oil pollution in the southern North Sea has almost halted Полный текст
2017
Stienen, Eric W.M. | Courtens, Wouter | Van de walle, Marc | Vanermen, Nicolas | Verstraete, Hilbran
Trends in oil rates of beached seabirds reflect temporal and spatial patterns in chronic oil pollution at sea. We analysed a long-term dataset of systematic beached bird surveys along the Belgian North Sea coast during 1962–2015, where extreme high oil contamination rates and consequently high mortality rates of seabirds during the 1960s used to coincide with intensive ship traffic. In the 1960s, >90% of all swimming seabirds that washed ashore were contaminated with oil and estimated oil-induced mortality of seabirds was probably several times higher than natural mortality. More than 50years later oil rates of seabirds have dropped to historically low levels while shipping is still very intense, indicating that chronic oil pollution has significantly declined. The declining trend is discussed in the light of a series of legislative measures that were enacted in the North Sea region to reduce oil pollution.
Показать больше [+] Меньше [-]Reliability and utility of citizen science reef monitoring data collected by Reef Check Australia, 2002–2015 Полный текст
2017
Done, Terence | Roelfsema, Chris | Harvey, Andrew | Schuller, Laura | Hill, Jocelyn | Schläppy, Marie-Lise | Lea, Alexandra | Bauer-Civiello, Anne | Loder, Jennifer
Reef Check Australia (RCA) has collected data on benthic composition and cover at >70 sites along >1000km of Australia's Queensland coast from 2002 to 2015. This paper quantifies the accuracy, precision and power of RCA benthic composition data, to guide its application and interpretation. A simulation study established that the inherent accuracy of the Reef Check point sampling protocol is high (<±7% error absolute), in the range of estimates of benthic cover from 1% to 50%. A field study at three reef sites indicated that, despite minor observer- and deployment-related biases, the protocol does reliably document moderate ecological changes in coral communities. The error analyses were then used to guide the interpretation of inter-annual variability and long term trends at three study sites in RCA's major 2002–2015 data series for the Queensland coast.
Показать больше [+] Меньше [-]Plastic debris straps on threatened blue shark Prionace glauca Полный текст
2017
Colmenero, Ana I. | Barría, Claudio | Broglio, Elisabetta | García-Barcelona, Salvador
Plastic debris straps on threatened blue shark Prionace glauca Полный текст
2017
Colmenero, Ana I. | Barría, Claudio | Broglio, Elisabetta | García-Barcelona, Salvador
Juveniles of blue shark Prionace glauca caught in pelagic longlines targeting tuna and swordfish in the Atlantic Ocean and the Mediterranean Sea were found entangled with plastic straps around their gill region. The plastic debris were identified as strapping bands and caused several degrees of injuries on the dorsal musculature and pectoral fins. They were also obstructing the gill slits probably causing breathing issues. These records were uploaded in the web site seawatchers.org, and highlight the potential of citizen science in revealing the occurrence of such problems which could help to measure the effects of plastic debris on marine life.
Показать больше [+] Меньше [-]Plastic debris straps on threatened blue shark Prionace glauca Полный текст
2017
Colmenero, Ana I. | Barría, Claudio | Broglio, Elisabetta | García-Barcelona, Salvador | Fundación Española para la Ciencia y la Tecnología
3 pages, 1 figure, 1 table | Juveniles of blue shark Prionace glauca caught in pelagic longlines targeting tuna and swordfish in the Atlantic Ocean and the Mediterranean Sea were found entangled with plastic straps around their gill region. The plastic debris were identified as strapping bands and caused several degrees of injuries on the dorsal musculature and pectoral fins. They were also obstructing the gill slits probably causing breathing issues. These records were uploaded in the web site seawatchers.org, and highlight the potential of citizen science in revealing the occurrence of such problems which could help to measure the effects of plastic debris on marine life | This work was supported by the Fundación Española para la Ciencia y la Tecnología (FECYT) (FCT-15-9567) | Peer Reviewed
Показать больше [+] Меньше [-]Oxidative stress and genotoxicity biomarker responses in tilapia (Oreochromis niloticus) exposed to environmental concentration of 1-nitropyrene Полный текст
2017
Bacolod, Eugene T. | Uno, Seiichi | Villamor, Shiela S. | Koyama, Jiro
The present study aimed to assess whether environmental 1-nitropyrene (1-NP) concentration will induce genotoxicity and oxidative damages in tilapia, lives in estuarine and brackish water. Tilapia were exposed to waterborne 1-NP. Cellular antioxidant enzyme activity of glutathione peroxidase and oxidative damage, i.e., lipid peroxidation, protein and DNA oxidation were used as biomarkers of oxidative stress, while the micronucleus test was used for evaluation of chromosomal damage and was used as an indication of genotoxicity. Results showed that all biomarkers for oxidative stress positively responded, and micronucleus and other nuclear abnormalities frequencies significantly increased (p<0.001). This study showed that environmentally relevant 1-NP concentration in test water (0.15ng/L) and in fish (3ng/kg) induced genotoxicity and oxidative stress. Micronuclei and other nuclear abnormalities were probably formed as a result of oxidative stress. In conclusion, exposure to lower waterborne 1-NP concentration can pose a risk to freshwater and estuarine organisms through accumulation.
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