细化搜索
结果 781-790 的 1,299
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.
显示更多 [+] 显示较少 [-]Habitat associations of floating debris and marine birds in the North East Pacific Ocean at coarse and meso spatial scales
2011
Titmus, Andrew J. | David Hyrenbach, K.
While many surface foraging seabirds ingest plastic, the spatial overlap of these far-ranging predators with debris aggregations at-sea is poorly understood. We surveyed concurrent distributions of marine birds and debris along a 4400km cruise track within a debris accumulation area in the North East Pacific Ocean using line and strip transect methods. Analysis of debris and bird distributions revealed associations with oceanographic and weather variables at two spatial scales: daily surveys and hourly transects. Hourly bird abundance (densities; 0–9 birds km⁻²) was higher in lower wind and shallower water. Hourly debris abundance (densities; 0–15,222 pieces km⁻²) was higher in lower wind, higher sea-level atmospheric pressure and deeper water. These results suggest that debris and seabird abundance and community structure are influenced by similar environmental processes, but in opposing ways, with only three far-ranging seabird species (Black-footed Albatross, Cook’s Petrel and Red-tailed Tropicbird) overlapping with high debris concentrations over meso-scales.
显示更多 [+] 显示较少 [-]Ostreopsis cf. ovata bloom in the northern Adriatic Sea during summer 2009: Ecology, molecular characterization and toxin profile
2011
Accoroni, Stefano | Romagnoli, Tiziana | Colombo, Federica | Pennesi, Chiara | Di Camillo, Cristina Gioia | Marini, Mauro | Battocchi, Cecilia | Ciminiello, Patrizia | Dell’Aversano, Carmela | Dello Iacovo, Emma | Fattorusso, Ernesto | Tartaglione, Luciana | Penna, Antonella | Totti, Cecilia
Intense blooms of the benthic dinoflagellate Ostreopsis cf. ovata have occurred in the northern Adriatic Sea since 2006. These blooms are associated with noxious effects on human health and with the mortality of benthic organisms because of the production of palytoxin-like compounds. The O. cf. ovata bloom and its relationships with nutrient concentrations at two stations on the Conero Riviera (northern Adriatic Sea) were investigated in the summer of 2009. O. cf. ovata developed from August to November, with the highest abundances in September (1.3×10⁶cellsg⁻¹ fw corresponding to 63.8×10³cellscm⁻²). The presence of the single O. cf. ovata genotype was confirmed by a PCR assay. Bloom developed when the seawater temperature was decreasing. Nutrient concentrations did not seem to affect bloom dynamics. Toxin analysis performed by high resolution liquid chromatography–mass spectrometry revealed a high total toxin content (up to 75pgcell⁻¹), including putative palytoxin and all the ovatoxins known so far.
显示更多 [+] 显示较少 [-]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.
显示更多 [+] 显示较少 [-]Pore water transport of enterococci out of beach sediments
2011
Phillips, Matthew C. | Solo-Gabriele, Helena M. | Reniers, A.J.H.M. | Wang, John D. | Kiger, Russell T. | Abdel-Mottaleb, Noha
Enterococci are used to evaluate the safety of beach waters and studies have identified beach sands as a source of these bacteria. In order to study and quantify the release of microbes from beach sediments, flow column systems were built to evaluate flow of pore water out of beach sediments. Results show a peak in enterococci (average of 10% of the total microbes in core) released from the sand core within one pore water volume followed by a marked decline to below detection. These results indicate that few enterococci are easily removed and that factors other than simple pore water flow control the release of the majority of enterococci within beach sediments. A significantly larger quantity and release of enterococci were observed in cores collected after a significant rain event suggesting the influx of fresh water can alter the release pattern as compared to cores with no antecedent rainfall.
显示更多 [+] 显示较少 [-]Antibiotic resistance of bacteria isolated from shrimp hatcheries and cultural ponds on Donghai Island, China
2011
Zhang, Yu Bin | Li, Yuan | Sun, Xing Li
The resistance of bacteria to 12 different antibiotics was investigated in shrimp farms on Donghai Island, China. Antibiotic-resistant bacteria were found to be widespread in shrimp farms, indicating a high environmental risk. Further, significant differences were found in bacterial strains among farms (ANOVA, p<0.05), showing resistance to antibiotics such as ampicillin, trimethoprim, compound sinomi, tetracycline, chloramphenicol and cefazolin. No significant differences in antibiotic resistance were found among 6 hatcheries evaluated in this study (ANOVA, p>0.05), between exalted and traditional shrimp ponds (ANOVA, p>0.05), and between cultural ponds and corresponding control water source sites (T-test, p>0.05). In cultural ponds, no significant difference in bacterial resistance to antibiotics was found between water and sediment (T-test, p>0.05), and antibiotic resistance of bacteria from water showed a significant positive correlation with that from sediment (p<0.05). Therefore, our study indicates that bacterial multiple antibiotic resistance (MAR) is more widespread in shrimp hatcheries than ponds.
显示更多 [+] 显示较少 [-]Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea
2011
Lazar, Bojan | Gračan, Romana
We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0–79.2cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ranging from <0.01 to 0.71g, and the ingestion was not significantly affected by sex or body size (all p>0.05). Marine debris averaged 2.2±8.0% of dry mass of gut content, with a maximum of 35% found in a juvenile turtle that most likely died due to debris ingestion. Considering the relatively high occurrence of debris intake and possible sub-lethal effects of even small quantities of marine debris, this can be an additional factor of concern for loggerheads in the Adriatic Sea.
显示更多 [+] 显示较少 [-]New threats of an old enemy: The distribution of the shipworm Teredo navalis L. (Bivalvia: Teredinidae) related to climate change in the Port of Rotterdam area, the Netherlands
2011
Paalvast, Peter | van der Velde, Gerard
The effects of four climate change scenarios for the Netherlands on the distribution of the shipworm upstream of the Rhine–Meuse estuary are described. Global warming will cause dry and warmer summers and decreased river discharges. This will extend the salinity gradient upstream in summer and fall and may lead to attacks on wooden structures by the shipworm. Scenarios including one or two degree temperature increases by 2050 compared to 1990 with a weak change in the air circulation over Europe will lead to an increased chance of shipworm damage upstream from once in 36years to once in 27 or 22years, respectively; however, under a strong change in air circulation, the chance of shipworm damage increases to once in 6 or 3years, respectively. The upstream expansion of the distribution of the shipworm will also be manifested in other northwest European estuaries and will be even stronger in southern Europe.
显示更多 [+] 显示较少 [-]Effects of the pharmaceuticals gemfibrozil and diclofenac on the marine mussel (Mytilus spp.) and their comparison with standardized toxicity tests
2011
Schmidt, Wiebke | O’Rourke, Kathleen | Hernan, Robert | Quinn, Brian
Human pharmaceuticals, like the lipid lowering agent gemfibrozil and the non-steroidal anti-inflammatory drug diclofenac are causing environmental concern. In this study, the marine mussel (Mytilus spp.) was exposed by injection to environmentally relevant and elevated (1μg/L and 1000μg/L) concentrations of both compounds and biomarker expression was observed. Gemfibrozil exposure induced biomarkers of stress (glutathione S-transferase and metallothionein) at both concentrations 24h and 96h after exposure, respectively. Biomarkers of damage (lipid peroxidation (LPO) and DNA damage) were significantly affected, as well as the biomarker for reproduction, alkali-labile phosphate assay, indicating the potential oxidative stress and endocrine disrupting effect of gemfibrozil. Diclofenac significantly induced LPO after 96h indicating tissue damage. Additionally standard toxicity tests using the marine species Vibrio fischeri, Skeletonema costatum and Tisbe battagliai showed differences in sensitivity to both drugs in the mg/L range. Results indicate a suite of tests should be used to give accurate information for regulation.
显示更多 [+] 显示较少 [-]Monitoring persistent organic pollutants in leatherback turtles (Dermochelys coriacea) confirms maternal transfer
2011
Stewart, Kelly R. | Keller, Jennifer M. | Templeton, Ryan | Kucklick, John R. | Johnson, Chris
To assess threats to endangered species, it is critical to establish baselines for contaminant concentrations that may have detrimental consequences to individuals or populations. We measured contaminants in blubber and fat from dead leatherback turtles and established baselines in blood and eggs in nesting turtles. In fat, blubber, blood and eggs, the predominant PCBs were 153+132, 187+182, 138+163, 118, and 180+193. Total PCBs, 4,4′-DDE, total PBDEs and total chlordanes were significantly and positively correlated between blood and eggs, suggesting maternal transfer. Significant positive relationships also existed between fat and blubber in stranded leatherbacks. Less lipophilic PCBs appeared to more readily transfer from females to their eggs. PBDE profiles in the four tissues were similar to other wildlife populations but different from some turtle studies. Concentrations were lower than those shown to have acute toxic effects in other aquatic reptiles, but may have sub-lethal effects on hatchling body condition and health.
显示更多 [+] 显示较少 [-]