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النتائج 1 - 9 من 9
Monitoring plastic ingestion by the northern fulmar Fulmarus glacialis in the North Sea
2011
van Franeker, Jan A. | Blaize, Christine | Danielsen, Johannis | Fairclough, Keith | Gollan, Jane | Guse, Nils | Hansen, Poul Lindhard | Heubeck, Martin | Jensen, Jens-Kjeld | Le Guillou, Gilles | Olsen, Bergur | Olsen, Kåre-Olav | Pedersen, John | Stienen, Eric W.M. | Turner, Daniel M.
The abundance of plastics in stomachs of northern fulmars from the North Sea is used in the OSPAR Ecological Quality Objective (EcoQO) for marine litter. The preliminary EcoQO defines acceptable ecological quality as the situation where no more than 10% of fulmars exceed a critical level of 0.1 g of plastic in the stomach. During 2003–2007, 95% of 1295 fulmars sampled in the North Sea had plastic in the stomach (on average 35 pieces weighing 0.31 g) and the critical level of 0.1 g of plastic was exceeded by 58% of birds, with regional variations ranging from 48 to 78%. Long term data for the Netherlands since the 1980s show a decrease of industrial, but an increase of user plastics, with shipping and fisheries as the main sources. The EcoQO is now also used as an indicator for Good Environmental Status in the European Marine Strategy Framework Directive.
اظهر المزيد [+] اقل [-]Inputs of antifouling paint-derived dichlorodiphenyltrichloroethanes (DDTs) to a typical mariculture zone (South China): Potential impact on aquafarming environment
2011
Yu, Huan-Yun | Shen, Ru-Lang | Liang, Yan | Cheng, Hefa | Zeng, E. Y. (Eddy Y.)
Existing evidence indicated that dichlorodiphenyltrichloroethane (DDT)-containing antifouling paints were an important source of DDT residues to mariculture zones. However, the magnitude of the impact on aquafarming environment has remained largely unknown. In the present study, the concentrations of DDT and its metabolites (designated as DDXs) were determined in harbor sediment and antifouling paint samples collected from a typical mariculture zone in South China. Compositional and concentration correlation analyses implicated the DDT-containing antifouling paints for fishing boat maintenance as an important source of DDT in the mariculture zone. The annual emission of DDXs to the study region was estimated at 0.58tons/yr. Furthermore, a comparison of the expected DDT loadings in pelagic fish and field measurements indicated that fish feed especially trash fish was a major source of DDTs in the fish body. Nevertheless, the use of DDT-containing antifouling paints should be limited to prevent further deterioration in aquafarming environment.
اظهر المزيد [+] اقل [-]Plastic contamination in the decapod crustacean Nephrops norvegicus (Linnaeus, 1758)
2011
Murray, Fiona | Cowie, Phillip Rhys
The aim of this study was to determine the extent Nephrops consumes plastics in the Clyde Sea and if this intake occurs through their diet. Plastic contamination was found to be high in Nephrops, 83% of the animals sampled contained plastics (predominately filaments) in their stomachs. Tightly tangled balls of plastic strands were found in 62% of the animals studied but were least prevalent in animals which had recently moulted. No significant difference in plastic load was observed between males and females. Raman spectroscopy indicated that some of the microfilaments identified from gut contents could be sourced to fishing waste. Nephrops fed fish seeded with strands of polypropylene rope were found to ingest but not to excrete the strands. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland and the high prevalence of plastics in Nephrops may have implications for the health of the stock.
اظهر المزيد [+] اقل [-]Fisheries mismanagement
2011
O’Leary, Bethan C. | Smart, James C.R. | Neale, Fiona C. | Hawkins, Julie P. | Newman, Stephanie | Milman, Amy C. | Roberts, Callum M.
We analysed the extent to which European politicians have adhered to scientific recommendations on annual total allowable catches (TACs) from 1987 to 2011, covering most of the period of the Common Fisheries Policy (CFP). For the 11 stocks examined, TACs were set higher than scientific recommendations in 68% of decisions. Politically-adjusted TACs averaged 33% above scientifically recommended levels. There was no evidence that the 2002 reform of the CFP improved decision-making, as was claimed at the time. We modelled the effects of such politically-driven decision-making on stock sustainability. Our results suggest that political adjustment of scientific recommendations dramatically increases the probability of a stock collapsing within 40years. In 2012 European fisheries policy will undergo a once-a-decade reform. Ten years ago radical reforms were promised but the changes failed to improve sustainability. It is likely that the 2012 reform will be similarly ineffective unless decision-making is changed so that catch allocations are based on science rather than politics.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]The destructive date-mussel fishery and the persistence of barrens in Mediterranean rocky reefs
2011
Guidetti, Paolo
The illegal and destructive fishery of date mussels (i.e. the endolithic mollusc Lithophaga lithophaga) reduces the bio-physical complexity of Mediterranean rocky reefs and dramatically impacts biodiversity. Although date-mussel fishermen do not directly impact sea urchins, these echinoids dramatically increase in abundance on rocky reefs impacted by date-mussel fishery (DMF). The recovery of rocky reefs affected by DMF is hampered by the intense unselective grazing of sea urchins on benthic organisms. No evidence is available, however, about the mechanisms that cause the increase in the population density of sea urchins. I demonstrated here that DMF creates a new microhabitat, i.e. the holes left empty after date mussels are extracted, where small-sized sea urchins take refuge and escape predation. This study thus sheds light on a mechanism through which DMF may locally increase sea urchin population density, contributing to maintain the rocks bare on the long term.
اظهر المزيد [+] اقل [-]Plastic debris ingestion by marine catfish: An unexpected fisheries impact
2011
Possatto, Fernanda E. | Barletta, Mario | Costa, Monica F. | Ivar do Sul, Juliana A. | Dantas, David V.
Plastic marine debris is a pervasive type of pollution. River basins and estuaries are a source of plastics pollution for coastal waters and oceans. Estuarine fauna is therefore exposed to chronic plastic pollution. Three important catfish species [Cathorops spixii (N=60), Cathorops agassizii (N=60) and Sciades herzbergii (N=62)] from South Western Atlantic estuaries were investigated in a tropical estuary of the Brazilian Northeast in relation to their accidental ingestion of plastic marine debris. Individuals from all three species had ingested plastics. In C. spixii and C. agassizii, 18% and 33% of individuals had plastic debris in their stomachs, respectively. S. herzbergii showed 18% of individuals were contaminated. All ontogenetic phases (juveniles, sub-adults and adults) were contaminated. Nylon fragments from cables used in fishery activities (subsistence, artisanal and commercial) played a major role in this contamination. These catfish spend their entire life cycles within the estuary and are an important feeding resource for larger, economically important, species. It is not yet possible to quantify the scale and depth of the consequences of this type of pollution. However, plastics are well known threat to living resources in this and other estuaries. Conservation actions will need to from now onto take plastics pollution into consideration.
اظهر المزيد [+] اقل [-]Petroleum hydrocarbon concentrations in ten commercial fish species along Tamilnadu coast, Bay of Bengal, India
2011
Veerasingam, S. | Venkatachalapathy, R. | Rājjā. | Sudhākar, Es | Rajeswari, V. | Asanulla, R Mohamed | Mohan, R. | Sutharsan, P.
Background, aim, and scope The aim of the present study was to evaluate the distribution of petroleum hydrocarbons in ten commercial fish species and water samples in three estuaries along Tamilnadu coast, Bay of Bengal, India. Materials and methods Fish and water samples collected from Tamilnadu coast, India, were extracted and analyzed for petroleum hydrocarbons by ultraviolet fluorescence (UVF) spectroscopy. Results The petroleum hydrocarbon concentration (PHC) in coastal waters and fish species varied between 2.28 and 14.02 μg/l and 0.52 and 2.05 μg/g, respectively. The highest PHC concentration was obtained in Uppanar estuarine waters (14.02 ± 0.83) and the lowest was observed in Vellar estuarine waters (2.28 ± 0.25). Discussion Among the ten fish species, Sardinella longiceps have high PHC concentration from all the locations. This study suggests that S. longiceps can be used as a good biological indicator for petroleum hydrocarbon pollution in water. Conclusions The concentration of petroleum hydrocarbons in coastal waters along Tamilnadu coast is markedly higher than that in the background, but there is no evidence for its increase in fish of this region. From a public health point, petroleum hydrocarbon residue levels in all fish samples analyzed in this study are considerably lower than the hazardous levels. Recommendations and perspectives At present, as Tamilnadu coastal area is in a rapid development stage of new harbour, chemical industries, power plants, oil exploration and other large-scale industries, further assessment of petroleum hydrocarbons and the various hydrodynamic conditions acting in the region are to be studied in detail and continuous pollution monitoring studies should be conducted for improving the aquatic environment. The results will also be useful for pollution monitoring program along the coastal region and also to check the levels of petroleum hydrocarbons.
اظهر المزيد [+] اقل [-]Image analysis application for the study of activated sludge floc size during the treatment of synthetic and real fishery wastewaters
2011
Mesquita, Daniela P. | Ribeiro, Roberta R. | Amaral, António L. | Ferreira, Eugénio C. | Coelho, Maria Alice Z.
BACKGROUND, AIM, AND SCOPE: Fishery wastewater treatment can be compromised due to seasonal production. The use of sequencing batch reactors is not completely successful, despite flexibility being one of the principal advantages. Most research on activated sludge is performed using synthetic wastewater to ensure a stable and constant feed. The current work compared biomass morphology and settling ability using image analysis of synthetic and real fishery wastewaters, with and without NaCl addition. RESULTS: The final effluent presented higher turbidity for both wastewaters after NaCl addition, and lower SVI values. For synthetic wastewater, NaCl addition led to the total aggregates' area (TA) increase from 1.46 to 2.09 mm2/μL, alongside the growth of intermediate aggregates into larger aggregates. The addition of NaCl to the fishery wastewater led to a decrease of the TA from 4.43 to 1.72 mm2/μL. The biomass composition decreased in larger and intermediate structures, opposite to the smaller aggregates' area percentage increase. DISCUSSION: NaCl addition to synthetic wastewater incited flocculation increasing sludge settling ability. A slight aggregate disruption was responsible for a turbidity increase. A strong deflocculation was identified in fishery wastewater with NaCl from the decrease of intermediate and large aggregates. This contrasted with pinpoint flocs release, which increased the turbidity levels. CONCLUSIONS, RECOMMENDATIONS, AND PERSPECTIVES: It could be established that synthetic wastewater biomass flocculation and fishery wastewater biomass deflocculation, observed during 0.5% NaCl experiments, were related to sludge settling and effluent turbidity changes. Furthermore, the biomass changes obtained with synthetic wastewater cannot be extrapolated to fishery wastewater.
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