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Application of Toxicity Identification Evaluation (TIE) procedures for the characterization and management of dredged harbor sediments Texto completo
2013
Montero, N. | Belzunce-Segarra, M.J. | Gonzalez, J-L. | Menchaca, I. | Garmendia, J.M. | Etxebarria, N. | Nieto, O. | Franco, J.
This study refers to the performance of Phase I Toxicity Identification Evaluation (TIE) procedures to identify the contaminants (i.e. organic compounds, metals and ammonia) exerting toxicity in marine sediments from the Pasaia harbor (Oiartzun estuary, northern Spain). The effectiveness of the manipulations to reduce toxicity was proved with the marine amphipod survival test (whole-sediment) and the sea urchin embryo-larval assay (elutriates).By means of TIEs it was concluded that organic compounds were the major contaminants exerting toxicity, although toxic effects by metals was also demonstrated. Additionally, the combination of Phase I treatments allowed to investigate the toxicity changes associated to the mobility of contaminants during dredging activities. Therefore, the performance of TIE procedures as another line of evidence in the decision-making process is recommended. They show a great potential to be implemented at different steps of the characterization and management of dredged harbor sediments.
Mostrar más [+] Menos [-]Ecotoxicological assessment of sediments from an urban marine protected area (Xixová-Japuí State Park, SP, Brazil) Texto completo
2013
Araujo, G.S. | Moreira, L.B. | Morais, R.D. | Davanso, M.B. | Garcia, T.F. | Cruz, A.C.F. | Abessa, D.M.S.
This study aimed to evaluate the environmental quality of the marine portion of Xixová-Japuí State Park (XJSP), an urban marine protected area, which is influenced by multiple contamination sources, by using ecotoxicological and geochemical analyses. Sediments were predominantly sandy, with low CaCO3 and organic matter contents, and presented contamination by metals (Cd,Cu,Zn). Acute toxicity was detected in three tested samples, and copepod exposed to sediments from four stations exhibited lower fecundities, despite the absence of significant effects. Contamination and toxicity seemed to be associated, suggesting that the environment is degraded and presents risks to the biota. Whole sediment TIE indicated ammonia as a main responsible for toxicity, suggesting sewage is a main contributor to sediment degradation. As external contamination sources seem to be negatively influencing the sediment quality, the park conservation objectives are not being fully reached, demanding actions to mitigate impacts.
Mostrar más [+] Menos [-]Climate change and the oceans – What does the future hold? Texto completo
2013
Bijma, Jelle | Pörtner, Hans-O. | Yesson, Chris | Rogers, Alex D.
Climate change and the oceans – What does the future hold? Texto completo
2013
Bijma, Jelle | Pörtner, Hans-O. | Yesson, Chris | Rogers, Alex D.
The ocean has been shielding the earth from the worst effects of rapid climate change by absorbing excess carbon dioxide from the atmosphere. This absorption of CO2 is driving the ocean along the pH gradient towards more acidic conditions. At the same time ocean warming is having pronounced impacts on the composition, structure and functions of marine ecosystems. Warming, freshening (in some areas) and associated stratification are driving a trend in ocean deoxygenation, which is being enhanced in parts of the coastal zone by upwelling of hypoxic deep water. The combined impact of warming, acidification and deoxygenation are already having a dramatic effect on the flora and fauna of the oceans with significant changes in distribution of populations, and decline of sensitive species. In many cases, the impacts of warming, acidification and deoxygenation are increased by the effects of other human impacts, such as pollution, eutrophication and overfishing.The interactive effects of this deadly trio mirrors similar events in the Earth’s past, which were often coupled with extinctions of major species’ groups. Here we review the observed impacts and, using past episodes in the Earth’s history, set out what the future may hold if carbon emissions and climate change are not significantly reduced with more or less immediate effect.
Mostrar más [+] Menos [-]Climate change and the oceans - What does the future hold? Texto completo
2013
Bijma, Jelle | Pörtner, Hans-Otto | Yesson, Chris | Rogers, A. D.
A baseline study of levels of mercury, arsenic, cadmium and lead in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea Texto completo
2013
Julshamn, Kaare | Duinker, Arne | Nilsen, Bente M. | Frantzen, Sylvia | Maage, Amund | Valdersnes, Stig | Nedreaas, Kjell
This study is one of several baseline studies that will provide basic and reliable information about the content of undesirable substances in important species of fish caught in Norwegian waters. Concentrations of metals in the muscle and liver of more than 800 Northeast Arctic cod caught at 32 sites in the Barents Sea are reported. The highest concentration of both mercury in the muscle and cadmium in the liver was found in cod caught in the western part of the Barents Sea, while the highest concentration of total arsenic was found in cod from the eastern part. The arsenic concentrations varied greatly among individual fish, ranging from 0.3 to 170mgkg−1 wet weight in the muscle. Such high levels of total arsenic have never previously been reported in any fish, and the primary factor for these high concentrations is likely to be the shrimp in the cod diet.
Mostrar más [+] Menos [-]The regrowth of phytoplankton cultures after UV disinfection Texto completo
2013
Martínez, Lucía F. | Mahamud, Manuel M. | Lavín, Antonio G. | Bueno, Julio L.
This study addresses how cultures of three phytoplankton species –Chaetoceros calcitrans, Chlorella autotrophica and Phaeocystis globosa – can recover from the effects of UV-C exposure if the cells are placed in a rich medium. Flow cytometry and pulse amplitude modulation (PAM) were used to determine cell recovery after UV treatment. The recovery of C. calcitrans was complete 9days after treatment. For C. autotrophica, the recovery was noticeable 5days after treatment. P. globosa only recovered if the UV dose did not exceed 7.3×105μWs/cm2. The recovery of the UV-treated cultures introduced to a regrowth medium, compared with the recovery of the irradiated cultures kept in their original environment, had two main characteristics: cell recovery was slower but was more efficient. This pattern of recovery has very important implications for real ballast water management systems because such systems discharge treated water into the environment.
Mostrar más [+] Menos [-]Quantitative analysis of plastic debris on recreational beaches in Mumbai, India Texto completo
2013
Jayasiri, H.B. | Purushothaman, C.S. | Veṇṇilā,
Plastic litter was quantified on four sandy beaches in Mumbai. The mean abundance of 7.49g and 68.83 items per square metre was recorded. The abundance of plastics significantly varied among the beaches showing an increasing trend in the southern part. The abundance of plastics by weight in Dadar was significantly higher than that in Aksa. The size fractionation of plastics proved that small particles (1–20mm) are predominant with 41.85% microplastics (1–5mm) which emphasizes the high risk to marine organisms due to possible ingestion. The highest quantity of microplastics was seen in Juhu beach (55.33%) followed by Versova, Aksa and Dadar. The major contributing factors for the abundance are beach usage for different activities such as recreational, religious and fishing which suggest that the land-based sources provide major inputs to plastic pollution in these beaches.
Mostrar más [+] Menos [-]Effects of elevated pCO2 on reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica Texto completo
2013
Effects of elevated pCO2 on reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica Texto completo
2013
We investigated the effects of elevated pCO2 in seawater both on the acute mortality and the reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica with the purpose of accumulating basic data for assessing potential environmental impacts of sub-sea geological storage of anthropogenic CO2 in Japan. Acute tests showed that nauplii of T. japonicus have a high tolerance to elevated pCO2 environments. Full life cycle tests on T. japonicus indicated NOEC=5800μatm and LOEC=37,000μatm. Adult B. japonica showed remarkable resistance to elevated pCO2 in the acute tests. Embryonic development of B. japonica showed a NOEC=1500μatm and LOEC=5400μatm. T. japonicus showed high resistance to elevated pCO2 throughout the life cycle and B. japonica are rather sensitive during the veliger stage when they started to form their shells.
Mostrar más [+] Menos [-]Seawater carbonate chemistry and reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica in a laboratory experiment Texto completo
2013
Kita, Jun | Kikkawa, Takashi | Asai, Takamasa | Ishimatsu, Atsushi
We investigated the effects of elevated pCO2 in seawater both on the acute mortality and the reproductive properties of the benthic copepod Tigriopus japonicus and gastropod Babylonia japonica with the purpose of accumulating basic data for assessing potential environmental impacts of sub-sea geological storage of anthropogenic CO2 in Japan. Acute tests showed that nauplii of T. japonicus have a high tolerance to elevated pCO2 environments. Full life cycle tests on T. japonicus indicated NOEC = 5800 µatm and LOEC = 37,000 µatm. Adult B. japonica showed remarkable resistance to elevated pCO2 in the acute tests. Embryonic development of B. japonica showed a NOEC = 1500 µatm and LOEC = 5400 µatm. T. japonicus showed high resistance to elevated pCO2 throughout the life cycle and B. japonica are rather sensitive during the veliger stage when they started to form their shells.
Mostrar más [+] Menos [-]Effects of suspended particles on the growth of two dominant phytoplankton species of Bohai Bay, China Texto completo
2013
Liu, Chunguang | Wang, Junli | Feng, Jianfeng | Peng, Shitao
Suspended particles (SP) are increasing dramatically in Bohai Bay, China and may affect the growth and composition of phytoplankton assembly. To determine the effects of SP on the growth of two dominant phytoplankton species, Phaeodactylum tricornutum Bohlin and Gymnodinium sp., we cultured and tested their growth characteristics under SP concentrations ranging from 0gL−1 to 0.8gL−1. Our results show that the increase in the SP concentrations results in significant decrease in the maximum cell densities and the maximum specific growth rates of these two species. The half maximal inhibitory concentration (IC50) of SP to P. tricornutum and Gymnodinium sp. were 1.07gL−1 and 0.68gL−1 respectively, indicating the inhibitory effect of SP on Gymnodinium sp. was greater than on P. tricornutum. These results suggest that SP inhibits the growth of the two algal species and P. tricornutum is more tolerant to SP than Gymnodinium sp.
Mostrar más [+] Menos [-]Optimization of an “in situ” subtidal rocky-shore sampling strategy for monitoring purposes Texto completo
2013
Gallon, R.K. | Ysnel, F. | Feunteun, E.
This study compared 2 standardized protocols to monitor subtidal rocky shores. We tested 2 sampling methods (temporal unit and quadrat) to assess the efficiency of extracting biota parameters (diversity, abundance, and biomass) of macroalgae, Mollusca, and Porifera with respect to time–cost and the number of sampling units. Species richness and occurrence of rocky subtidal habitats were better described by visual censuses than by quadrats. The same estimated richness was provided by the 2 methods. The association of a visual census and a quadrat was the most efficient way for responding to the requirements. A minimum of 5 sampling units per discrete area is recommended for accurately describing habitats. Then, we tested the sensitivity of the proposed protocol on the Bizeux Islet to study the variations of community structures according to depth and station. Based on the results, recommendations for monitoring purposes have been proposed according to European directives.
Mostrar más [+] Menos [-]Surface ozone variations at a rural area in the northeast of the Iberian Peninsula Texto completo
2013
Adame, Jose A. | Sole, Jose G.
The aim of this paper is to study the levels and variability of surface ozone in the lower Ebre Valley and to estimate whether this surface ozone has its origin in local photochemical processes or in long–range transport. Surface ozone data series of twelve years (1994–2005) have been used from a rural area (Ebre Observatory) together with three years (2003–2005) data of nitrogen dioxide (NO2). Ozone trends over the whole seasonal period, weekly and daily variations and exceedances of the legal threshold have been investigated. Furthermore, a representative ozone event has been studied in detail. Using ozone data from the twelve–year period resulted in a positive trend with an increase of 2.18 μg m–3 year–1 and 0.64 μg m–3 year–1 in summer and winter, respectively. The seasonal evolution of ozone gives a minimum value in winter and a maximum higher than 75 μg m–3 associated with the minimum values of NO2. Ozone– NO2 variation shows a weak ozone increase on weekdays and a small decrease in NO2 concentrations at the weekends. Hence, a weekend effect is not observed. Ozone and NO2 concentrations show a diurnal pattern with NO2 peaks both in the early morning and in the evening, and maximum ozone concentrations, higher than 90–100 μg m–3, from 12:00 to 18:00 UTC in the warmer seasons. The threshold for the protection of human health has been exceeded from March to September each year, with a mean of 33 times per year. An event with high ozone levels originated by transport processes from the Mediterranean area was also analysed. The results suggest that high ozone could be caused mainly by transport mechanisms, and the Ebre valley could be considered to be a natural communication channel between the western Mediterranean basin and the Atlantic Ocean.
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