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Gillnet fisheries as a major mortality factor of Magellanic penguins in wintering areas
2011
Cardoso, Luis Gustavo | Bugoni, Leandro | Mancini, Patrícia Luciano | Haimovici, Manuel
The incidental capture in fisheries is probably the main conservation problem affecting seabirds. While the capture of albatrosses and petrels on longline hooks is well-known worldwide, the bycatch of diving seabirds in gillnets is an overlooked conservation problem. During a winter coastal fishing trip, the capture of Magellanic penguins (Spheniscus magellanicus) was recorded in driftnet and bottom setnet fisheries for the first time in southern Brazil. The highest captures rates were found in driftnets, from 146.5 to 545.5penguins/km² of net and a total of 56 dead penguins were recorded. In the bottom gillnet, a total of 12 birds were killed and the capture rates varied from 41.7 to 125.0penguins/km² of net. Although preliminary, the results presented in this paper were consistent between sets. If we consider the magnitude of driftnet and setnet fishing fleets, and that most dead penguins were adults, the impact upon Magellanic penguin populations is probably significant.
Show more [+] Less [-]Molecular ecological responses of dinoflagellate, Karenia mikimotoi to environmental nitrate stress
2011
Lei, Qiang-Yong | Lü, Song-Hui
Karenia mikimotoi is one of the most important harmful algal species in the Chinese coastal waters, and which produce hemolytic toxins and ichthyotoxins, resulting in devastating economic losses. Previous studies demonstrated that the increase of nitrate concentration could promote the growth and reproduction of K. mikimotoi. However, the intrinsic mechanisms regarding the effects of nitrate on the K. mikimotoi photosynthesis, nucleic acid replication and differential protein expression remain to be elucidated. Our study demonstrated that nitrate stress inhibited growth of K. mikimotoi (p<0.01). Algal chlorophyll fluorescence intensity varied slightly while algal cell cycle succession was significantly retarded by nitrate stress (p<0.05). Sixteen proteins were detected only in nitrate-limited cultures which related to nitrate transport, signal transduction, amino acid metabolism, DNA repair and hemolysin manufacture. Eleven proteins were detected only in nitrate-replete sample and were related to photorespiration, reproduction and growth, assistance of protein modification, cytoskeleton stability and signal transduction. Based on analysis of differential proteomic functional annotations, we hypothesized a proteomic response mechanism of K. mikimotoi to environmental nitrate stress.
Show more [+] Less [-]Assessment of sacrificial anode impact by aluminum accumulation in mussel Mytilus edulis: A large-scale laboratory test
2011
Mao, Andrea | Mahaut, Marie-Laure | Pineau, Samuel | Barillier, Daniel | Caplat, Christelle
Since the early 1960s, the application of aluminum alloy sacrificial anodes to mitigate marine corrosion has been well known. The aim of this work was to study aluminum bioconcentration in Mytilus edulis by an in vitro test performed in two tanks: the first containing non-contaminated water (NCW) and the second containing aluminum-contaminated water (CW) (530μgL⁻¹) released by sacrificial anode. The mussels were collected and examined over a period of 8weeks. A comparison between the aluminum concentrations in the digestive glands of mussels from the CW and NCW tanks shows that the highest value (1700mg/kgd.w.) was found in the CW mussels collected after 13days. In NCW, the mean aluminum concentration in digestive glands during the test was 281mg/kgd.w. The rapid concentration decrease in digestive glands is probably due to the inhibition of filtering activity due to valve closure at the high concentration as well as the induction of the detoxification response.
Show more [+] Less [-]Integrated use of biomarkers in the mussel Mytilus galloprovincialis for assessing off-shore gas platforms in the Adriatic Sea: Results of a two-year biomonitoring program
2011
Gomiero, Alessio | Da Ros, Luisa | Nasci, Cristina | Meneghetti, Francesca | Spagnolo, Alessandra | Fabi, Gianna
Despite a large number of gas platforms existing in the Adriatic Sea, which is a semi-enclosed basin characterized by a slow turnover rate and increasing industrial as well as other anthropogenic activities, the effects of these structures on the aquatic ecosystem require further investigation. Since 1998, multidisciplinary studies have been performed by CNR-ISMAR to comply with legislation and to support the development of protocols for the monitoring of offshore activities in the Adriatic Sea. The present study was developed to implement a biomonitoring plan to assess the ecotoxicological effects of the extraction activities of an off-shore gas platform. Biomarkers were evaluated in mussels collected from the platform in relation to physiological stress, DNA damage, cellular damage, oxidative stress and exposure effects. Organic contaminants and trace element bioaccumulation were also assessed in the soft body of the mussels to correlate bioaccumulation of pollutants with biomarker responses. The results indicate an absence of platform-related environmental stress.
Show more [+] Less [-]Testes specific accumulation of tributyltin in turbot Scophthalmus maximus from the southern Baltic Sea
2011
Gosz, E. | Horbowy, J. | Ruczyńska, W.
Concentrations of tributyltin (TBT) and its breakdown products, dibutyltin (DBT) and monobutyltin (MTB), were measured in tissues of male turbot Scophthalmus maximus from the Gulf of Gdańsk (GDA) and the Pomeranian Bay (POM) in the southern Baltic Sea. The fish (n=206) were collected during the spawning seasons of 2008–2009. All specimens were at the same maturity stage and in full breeding condition. The ripe testes of the turbot appeared to be a target tissue for TBT accumulation. We report that TBT is extensively eliminated at the specific whole-body level and that the males from TBT-contaminated location (GDA) reach this specific level at 23–24cm in total length.
Show more [+] Less [-]Seasonal and spatial variability of water quality parameters in the Port of Genoa, Italy, from 2000 to 2007
2011
Ruggieri, N. | Castellano, M. | Capello, M. | Maggi, S. | Povero, P.
This paper presents the results of the statistical analysis of a set of physico-chemical and biological water quality parameters, monthly collected from 2000 to 2007 in the Genoa Harbour area (Ligurian Sea). We applied multivariate methods, such as principal component analysis (PCA) and dynamic factor analysis (DFA) for investigating the spatial and temporal variability and for providing important background information on pollution problems in the region. PCA evidenced the role of the sewage and river discharges and of the exchanges with the open sea in determining the harbour water quality. DFA was used to estimate underlying common trends in the time series. The DFA results partly show a general improvement of water quality over the 8-years period. However, in other areas, we found inter-annual variations but no significant multi-annual trend. Furthermore, we included meteorological variables in our statistical analyses because of their potential influence on the water quality parameters. These natural forcings explain part of the variability in water quality parameters that are superimposed on the dominating anthropogenic pollution factors.
Show more [+] Less [-]Biodegradation of polycyclic aromatic hydrocarbons by a halotolerant bacterial strain Ochrobactrum sp. VA1
2011
Arulazhagan, P. | Vasudevan, N.
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in the environment and are derived from both man-made and natural resources. The present study is focused on the degradation of PAHs by a halotolerant bacterial strain under saline conditions. The bacterial strain VA1 was isolated from a PAH-degrading consortium that was enriched from marine water samples that were collected from different sites at Chennai, India. In the present study, a clearing zone formed on PAH-amended mineral salt agar media confirmed the utilization of PAH by the bacterial strain VA1. The results show that the strain VA1 was able to degrade anthracene (88%), phenanthrene (98%), naphthalene (90%), fluorene (97%), pyrene (84%), benzo(k)fluoranthene (57%) and benzo(e)pyrene (50%) at a 30g/L NaCl concentration. The present study reveals that the VA1 strain was able to degrade PAHs in petroleum wastewater under saline conditions. The promising PAH-degrading halotolerant bacterial strain, VA1, was identified as Ochrobactrum sp. using biochemical and molecular techniques.
Show more [+] Less [-]Distribution of butyltins in the waters and sediments along the coast of India
2011
Garg, Anita | Meena, Ram M. | Jadhav, Sangeeta | Bhosle, Narayan B.
Water and surface sediment samples were analyzed for butyltins (TBT, DBT, MBT) from various ports along the east and west coast of India. The total butyltin (TB) in water samples varied between ∼1.7 and 342ngSnl⁻¹, whereas for sediments it varied between below detection limit to 14861ngSng⁻¹ dry weight of sediment. On an average Chennai port recorded the highest level of butyltins in the sediments while Paradip recorded the highest level of butylins in the waters. A fairly good relationship between the TB in the sediment and overlying water samples, as well as between organic carbon and TB, implicates the importance of adsorption/desorption process in controlling the levels of TBT in these port areas. In India the data on organotin pollution is very sparse; most of the port areas have been surveyed for butyltins for the first time during this study.
Show more [+] Less [-]Environmental toxicology: Population modeling of cod larvae shows high sensitivity to loss of zooplankton prey
2011
Stige, Leif Christian | Ottersen, Geir | Hjermann, Dag Ø | Dalpadado, Padmini | Jensen, Louise K. | Stenseth, Nils Chr
Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to loss of prey at the given life stage. We here apply a statistical recruitment model for Northeast Arctic cod to evaluate the sensitivity of cod cohorts to loss of zooplankton prey, for example following an oil spill. The calculations show that cod cohorts are highly sensitive to possible zooplankton biomass reductions in the distribution area of the cod larvae, and point to a need for more knowledge about oil-effects on zooplankton. Our study illustrates how knowledge about population dynamics may guide which indirect effects to consider in environmental impact studies.
Show more [+] Less [-]Temporal changes in Sphingomonas and Mycobacterium populations in mangrove sediments contaminated with different concentrations of polycyclic aromatic hydrocarbons (PAHs)
2011
Guo, Chuling | Ke, Lin | Dang, Zhi | Tam, Nora Fungyee
The change in community diversity and structure of the indigenous, dominant, polycyclic aromatic hydrocarbon (PAH)-degrading bacterial genera, Sphingomonas and Mycobacterium, due to contamination in the environment is not very well known. A combination of PCR-DGGE with specific primers and a cultivation-dependent microbiological method was used to detect different populations of Sphingomonas and Mycobacterium in mangrove sediments. The structure of the entire bacterial community (including Sphingomonas) did not show a shift due to environmental contamination, whereas the diversity of Mycobacterium populations in mangrove sediments with higher PAH contamination increased from exposure between Day 0 and Day 30. The isolated Mycobacterium strains migrated to the same position as the major bands of the bacterial communities in Mycobacterium-specific DGGE. A dioxygenase gene system, nidA, which is commonly found in PAH-degrading Mycobacterium strains, was also detected in the more highly contaminated sediment slurries. The present study revealed that Mycobacterium species were the dominant PAH-degraders and played an important role in degrading PAHs in contaminated mangrove sediments.
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