Refine search
Results 771-780 of 1,955
Biological impacts of enhanced alkalinity in Carcinus maenas Full text
2013
Cripps, Gemma | Widdicombe, Stephen | Spicer, John I. | Findlay, Helen S
Biological impacts of enhanced alkalinity in Carcinus maenas Full text
2013
Cripps, Gemma | Widdicombe, Stephen | Spicer, John I. | Findlay, Helen S
Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals’ acid–base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid–base balance in this comparatively robust crustacean species.
Show more [+] Less [-]Biological impacts of enhanced alkalinity in Carcinus maenas Full text
2013
Cripps, Gemma | Widdicombe, Stephen | Spicer, John I | Findlay, Helen S
Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals' acid-base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid-base balance in this comparatively robust crustacean species.
Show more [+] Less [-]Quantitative analysis of plastic debris on recreational beaches in Mumbai, India Full text
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.
Show more [+] Less [-]Spatial and long-term analyses of reference and sewage-impacted sites in the SW Atlantic (38°S, 57°W) for the assessment of sensitive and tolerant polychaetes Full text
2013
Sánchez, María A. | Jaubet, María L. | Garaffo, Griselda V. | Elías, Rodolfo
Discharges of effluent in urbanized littoral areas produce nonlinear changes in benthic organisms. Data on the composition of the benthic community are often used to obtain environmental quality classifications that serve to indicate the health of the environment. This study conducted a comparative analysis of the polychaetes associated with mussel beds and related these results to the values of environmental variables at both reference and sewage-impacted sites over a 10year period in a rocky intertidal habitat on the coast of the SW Atlantic. The results of the study showed spatial and temporal differences in the abundance and dominance of the polychaetes. The study also furnished evidence of a decrease in the environmental quality of the area. This study allowed the classification of the polychaetes into ecological groups, facilitating the calculation of environmental quality indexes.
Show more [+] Less [-]Broad-scale patterns of tissue-δ15N and tissue-N indices in frondose Ulva spp.; Developing a national baseline indicator of nitrogen-loading for coastal New Zealand Full text
2013
Barr, Neill G. | Dudley, Bruce D. | Rogers, Karyne M. | Cornelisen, Christopher D.
A survey of tissue-δ15N and tissue-N values in the green macroalga, Ulva, was conducted around the coast of New Zealand to determine if these indices could be used as indicators of anthropogenic nutrient loading in coastal waters. In addition, data from four case studies showed temporal and spatial responses of tissue-δ15N and tissue-N in Ulva to significant terrestrial nutrient inputs. Tissue-δ15N in Ulva from ‘natural’ exposed coastal sites showed a relatively narrow baseline range of values (6.6±0.1–8.8±0.1‰) in both summer and winter that was consistent throughout New Zealand. Departures in Ulva tissue-δ15N ratios outside this range, particularly when coupled with high (>3.1%) tissue-N values, indicate significant contributions of terrestrially-derived nitrogen to coastal seawater. We note that tissue-N content is also affected by exposure, light and season; however provided such factors are taken into account Ulva can be a cost-effective indicator of relative changes in both source and amount of nitrogen-loading.
Show more [+] Less [-]Chemometric evaluation of the heavy metals distribution in waters from the Dilovası region in Kocaeli, Turkey Full text
2013
Bingöl, Deniz | Ay, Ümit | Karayünlü Bozbaş, Seda | Uzgören, Nevin
The main objective of this study was to test water samples collected from 10 locations in the Dilovası area (a town in the Kocaeli region of Turkey) for heavy metal contamination and to classify the heavy metal (Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb and Hg) contents in water samples using chemometric methods. The heavy metals in the water samples were identified using inductively coupled plasma-mass spectrometry (ICP-MS). To ascertain the relationship among the water samples and their possible sources, the correlation analysis, principal component analysis (PCA), and cluster analysis (CA) were used as classification techniques. About 10 water samples were classified into five groups using PCA. A very similar grouping was obtained using CA.
Show more [+] Less [-]Microbiological composition of native and exotic clams from Tagus estuary: Effect of season and environmental parameters Full text
2013
Anacleto, Patrícia | Pedro, Sónia | Nunes, Maria Leonor | Rosa, Rui | Marques, António
The influence of seasonal and environmental parameters on the occurrence of bacteria was investigated in two clam species (Venerupis pullastra and Ruditapes philippinarum), water and sediment from the Tagus estuary. Total viable counts (TVC), Escherichia coli, Salmonella spp. and Vibrio spp. were evaluated during one-year. Overall, significant seasonal variations were found in both sampling sites, especially for E. coli and Vibrio spp. levels. In summer, significantly higher Vibrio spp. levels were found in R. philippinarum and sediment samples, but not in V. pullastra clams and water samples. In contrast, significantly higher TVC and E. coli levels were observed in winter months in water and sediment samples. Salmonella spp. was generally isolated when higher levels of E. coli were detected, particularly in R. philippinarum. This study is useful for authorities to develop monitoring strategies for coastal contamination and to estimate human health risks associated with the consumption of bivalves.
Show more [+] Less [-]Metals contamination along the watershed and estuarine areas of southern Bohai Sea, China Full text
2013
Xu, Li | Wang, Tieyu | Ni, Kun | Liu, Shijie | Wang, Pei | Xie, Shuangwei | Meng, Jing | Zheng, Xiaoqi | Lü, Yonglong
Distributions and magnitude of metals in water, sediment and soil collected from the watershed and estuarine areas of southern Bohai Sea, were investigated. The largest dissolved concentrations of As, Cu and Zn in water were 347.70, 2755.00, 2076.00μg/L, respectively, much higher than corresponding drinking water guidelines. The greatest concentrations of Cu, Zn, Cr, Ni, Pb, As and Cd in sediments were 1462.2, 1602.17, 196.43, 67.15, 63.54, 73.86 and 1.41mg/kg, dw, respectively. The mean concentrations of Cu, Ni, Cd, Zn, Cr, Pb and As in soils were 24.67, 24.73, 0.14, 64.75, 56.52, 25.12 and 9.34mg/kg, dw, respectively. Land use was confirmed to be an important factor of influence on soil metal concentrations. Metal contents along the watershed of Jie River were significantly greater than in other locations. The detection of metals in relatively high concentrations from different environmental matrices in this region indicates the necessity of further studies.
Show more [+] Less [-]Ingestion of marine debris plastic by the wedge-tailed shearwater Ardenna pacifica in the Great Barrier Reef, Australia Full text
2013
Verlis, K.M. | Campbell, M.L. | Wilson, S.P.
We present the first evidence of ingestion of plastic by seabirds from the southern Great Barrier Reef (GBR), Australia. The occurrence of marine debris ingestion in the wedge-tailed shearwater, Ardenna pacifica, on Heron Island was the focus of this preliminary research. Our findings indicate that 21% of surveyed chicks are fed plastic fragments by their parents, having ingested 3.2 fragments on average. The most common colours of ingested plastic fragments were off/white (37.5%) and green (31.3%). Ingested fragments had a mean size of 10.17±4.55mm and a mean weight of 0.056±0.051g. Our results indicate that further research is critical to understanding the extent of ingestion, colour preferences, and what impacts ingestion may have on these and other seabird populations in the GBR.
Show more [+] Less [-]Modeling air concentrations and risk of carcinogens and co–carcinogens in Gibraltar and source apportionment of nearby industrial facilities Full text
2013
Fauser, Patrik | Sanderson, Hans | Lofstrom, Per
Airborne exposures of carcinogenic and co–carcinogenic pollutants, emitted from industries and various diffuse sources in a 10km radius of Gibraltar, were calculated at the west side of the Rock of Gibraltar facing the Bay. 2005 and 2008 industrial annual emission rates reported to E–PRTR and 2005 municipal diffuse annual emission rates were entered in OML–Multi, a multi–source version of an atmospheric Gaussian plume local scale dispersion model. The model results reveal that carcinogens PAH, represented by benzo[a]pyrene (BaP), arsenic and nickel, and potentially chromium are the priority pollutants with respect to human cancer risk and that the contribution from industrial sources on the Spanish coastal area exceeds that from the diffuse sources from adjacent Spanish municipalities. There is a decrease in annual mean air concentrations from industrial emissions between the years 2005 and 2008. The assessment of contribution to the Gibraltar air concentrations of the priority pollutants from industrial sources shows that refinery CEPSA, chemical industry Petresa and petroleum industry Lubricantes del Sur are significant for nickel. Chemical industry Interquisa is significant for PAHs with a notable decrease in PAH emissions from 2006 to 2007, whereas the contribution from CEPSA is more constant. For arsenic only CEPSA shows a continuous trend and contributes to the 2008 air concentration together with sewerage Edar de la Linea de la Concepcion. CEPSA and metal industry Acerinox contribute the most to the chromium air concentrations. NO2/NOx is the most critical co–carcinogen and electricity plant Central Termica Los Barrios, CEPSA, electricity plant Generacion Electrica Peninsular and electricity plant Cogeneracion de Interquisa are the most significant contributors to the air concentrations in Gibraltar. Pollutant contributions from CEPSA flaring, ship traffic in the Bay and Strait, local road traffic and local diesel generators are currently un–quantified.
Show more [+] Less [-]Risk assessment for exemptions from ballast water management – The Baltic Sea case study Full text
2013
David, Matej | Gollasch, Stephan | Leppäkoski, Erkki
The International Convention for the Control and Management of Ship’s Ballast Water and Sediments sets requirements to prevent organism transfers. Vessels on certain routes can be exempted from such requirements based on risk assessment (RA). As the convention nears its entry into force, the interest in exemptions increases. Such RA should be conducted according to the International Maritime Organization G7 Guidelines. We present a RA study for exemptions applied to intra-Baltic shipping considering different RA methods, i.e., environmental matching, species specific method including target species and species biogeographical aspects. As reliable species data in the ports considered are unavailable and following the precautionary principle, no exemptions should be granted. To ensure data reliability, port baseline surveys and regular monitoring programs should be undertaken during the exemption period as new species found influence the RA result. The RA model prepared is considered as of value to other areas worldwide.
Show more [+] Less [-]