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Impact of hypoxia on the structure and function of benthic epifauna in Tolo Harbour, Hong Kong Texto completo
2011
Fleddum, A. | Cheung, S.G. | Hodgson, P. | Shin, P.K.S.
In Tolo Harbour, Hong Kong, where hypoxia occurs periodically, a large amount of benthic epifauna was found to be absent in the summer but become abundant again in the winter. This observation may indicate that some species are sensitive in detecting low dissolved oxygen (DO) levels and are able to escape from the harbour to more oxygenated, open waters when conditions deteriorate and return when DO levels are improved. Analysis of biological traits of these animals showed that 58% of the categories showed significant differences between the community structure in summer and winter. The significant biological traits of the few species, which remained in the harbour under the summer’s hypoxic conditions suggested adaptation rather than opportunism to the low DO levels. Our data also showed that trawling can increase DO at the bottom and may benefit the less sensitive species that remained in the habitat during the summer.
Mostrar más [+] Menos [-]Hypoxia in Manila Bay, Philippines during the northeast monsoon Texto completo
2011
Jacinto, Gil S. | Sotto, Lara Patricia A. | Senal, Maria Isabel S. | Diego-McGlone, Maria Lourdes San | Escobar, Ma. Teresa L. | Amano, Atsuko | Miller, Todd W.
Herein we present results from one of the first extensive bay-wide oceanographic surveys of Manila Bay, wherein 31 stations were sampled during the northeast monsoon (cold and dry season). A band of hypoxic bottom water (dissolved oxygen <2.8mg/L) spanned the midsection of the bay from east to west. Bottom nitrate concentrations (5.7–16.8μM; avg. 11.1μM) and total organic carbon values in sediments (1.7–3.1%; avg. 2.4%) were high in the midsection, which coincided with the band of hypoxic bottom water. Physical processes and site-specific accumulation of organic material likely lead to hypoxic conditions in Manila Bay, even during the northeast monsoon period when the water column is relatively well mixed. The results of this study complement the previously reported widespread hypoxia that occurs during the rainy season. Thus, hypoxia may be pervasive in the bay throughout the year, although it varies in intensity and spatial extent.
Mostrar más [+] Menos [-]Estuarine ecological risk based on hepatic histopathological indices from laboratory and in situ tested fish Texto completo
2011
Costa, Pedro M. | Caeiro, Sandra | Lobo, Jorge | Martins, Marta | Ferreira, Ana M. | Caetano, Miguel | Vale, Carlos | DelValls, T Ángel | Costa, Maria H.
Juvenile Senegalese soles were exposed through 28-day laboratory and field (in situ) bioassays to sediments from three sites of the Sado estuary (W Portugal): a reference and two contaminated by metallic and organic contaminants. Fish were surveyed for ten hepatic histopathological alterations divided by four distinct reaction patterns and integrated through the estimation of individual histopathological condition indices. Fish exposed to contaminated sediments sustained more damage, with especial respect to regressive changes like necrosis. However, differences were observed between laboratory- and field-exposed animals, with the latest, for instance, exhibiting more pronounced fatty degeneration and hepatocellular eosinophilic alteration. Also, some lesions in fish exposed to the reference sediment indicate that in both assays unaccounted variables produced experimental background noise, such as hyaline degeneration in laboratory-exposed fish. Still, the field assays yielded results that were found to better reflect the overall levels of contaminants and physico-chemical characteristics of the tested sediments.
Mostrar más [+] Menos [-]Recommendations on methods for the detection and control of biological pollution in marine coastal waters Texto completo
2011
Olenin, Sergej | Elliott, Michael | Bysveen, Ingrid | Culverhouse, Phil F. | Daunys, Darius | Dubelaar, George B. J. | Gollasch, Stephan | Goulletquer, Philippe | Jelmert, Anders | Kantor, Yuri | Mezeth, Kjersti Bringsvor | Minchin, Dan | Occhipinti-ambrogi, Anna | Olenina, Irina | Vandekerkhove, Jochen
Recommendations on methods for the detection and control of biological pollution in marine coastal waters Texto completo
2011
Olenin, Sergej | Elliott, Michael | Bysveen, Ingrid | Culverhouse, Phil F. | Daunys, Darius | Dubelaar, George B. J. | Gollasch, Stephan | Goulletquer, Philippe | Jelmert, Anders | Kantor, Yuri | Mezeth, Kjersti Bringsvor | Minchin, Dan | Occhipinti-ambrogi, Anna | Olenina, Irina | Vandekerkhove, Jochen
Adverse effects of invasive alien species (IAS), or biological pollution, is an increasing problem in marine coastal waters, which remains high on the environmental management agenda. All maritime countries need to assess the size of this problem and consider effective mechanisms to prevent introductions, and if necessary and where possible to monitor, contain, control or eradicate the introduced impacting organisms. Despite this, and in contrast to more enclosed water bodies, the openness of marine systems indicates that once species are in an area then eradication is usually impossible. Most institutions in countries are aware of the problem and have sufficient governance in place for management. However, there is still a general lack of commitment and concerted action plans are needed to address this problem. This paper provides recommendations resulting from an international workshop based upon a large amount of experience relating to the assessment and control of biopollution. Highlights ► We summarize the results of an international workshop on marine biopollution. ► We recommend science-based information support for bioinvasion management. ► We outline types of bioinvasion monitoring and consider topical research needs. ► We emphasize the role of taxonomy training and public involvement. ► Biopollution should be treated in the same way as any other type of pollution.
Mostrar más [+] Menos [-]Recommendations on methods for the detection and control of biological pollution in marine coastal waters Texto completo
2011
Olenin, Sergej | Elliott, Michael | Bysveen, Ingrid | Culverhouse, Phil F. | Daunys, Darius | Dubelaar, George B.J. | Gollasch, Stephan | Goulletquer, Philippe | Jelmert, Anders | Kantor, Yuri | Mézeth, Kjersti Bringsvor | Minchin, Dan | Occhipinti-Ambrogi, Anna | Olenina, Irina | Vandekerkhove, Jochen
Adverse effects of invasive alien species (IAS), or biological pollution, is an increasing problem in marine coastal waters, which remains high on the environmental management agenda. All maritime countries need to assess the size of this problem and consider effective mechanisms to prevent introductions, and if necessary and where possible to monitor, contain, control or eradicate the introduced impacting organisms. Despite this, and in contrast to more enclosed water bodies, the openness of marine systems indicates that once species are in an area then eradication is usually impossible. Most institutions in countries are aware of the problem and have sufficient governance in place for management. However, there is still a general lack of commitment and concerted action plans are needed to address this problem. This paper provides recommendations resulting from an international workshop based upon a large amount of experience relating to the assessment and control of biopollution.
Mostrar más [+] Menos [-]Recommendations on methods for the detection and control of biological pollution in marine coastal waters Texto completo
2011
Olenin, Sergej | Elliott, Michael | Bysveen, Ingrid | Culverhouse, Phil F. | Daunys, Darius | Dubelaar, George B.J. | Gollasch, Stephan | Goulletquer, Philippe | Jelmert, Anders | Kantor, Yuri | Mézeth, Kjersti Bringsvor | Minchin, Dan | Occhipinti, Anna | Olenina, Irina | Vandekerkhove, Jochen
Adverse effects of invasive alien species (IAS), or biological pollution, is an increasing problem in marine coastal waters, which remains high on the environmental management agenda. All maritime countries need to assess the size of this problem and consider effective mechanisms to prevent introductions, and if necessary and where possible to monitor, contain, control or eradicate the introduced impacting organisms. Despite this, and in contrast to more enclosed water bodies, the openness of marine systems indicates that once species are in an area then eradication is usually impossible. Most institutions in countries are aware of the problem and have sufficient governance in place for management. However, there is still a general lack of commitment and concerted action plans are needed to address this problem. This paper provides recommendations resulting from an international workshop based upon a large amount of experience relating to the assessment and control of biopollution.
Mostrar más [+] Menos [-]Relationship between valve activity, microalgae concentration in the water and toxin accumulation in the digestive gland of the Pacific oyster Crassostrea gigas exposed to Alexandrium minutum Texto completo
2011
Haberkorn, Hansy | Tran, Damien | Massabuau, Jean-charles | Ciret, Pierre | Savar, Veronique | Soudant, Philippe
Relationship between valve activity, microalgae concentration in the water and toxin accumulation in the digestive gland of the Pacific oyster Crassostrea gigas exposed to Alexandrium minutum Texto completo
2011
Haberkorn, Hansy | Tran, Damien | Massabuau, Jean-charles | Ciret, Pierre | Savar, Veronique | Soudant, Philippe
The complexity of the relationships between Alexandrium minutum (Am.) concentration in the water ([A.m.](w)), Paralytic Shellfish Poisoning contamination in the digestive gland ([PSP](dg)) and valve behavior was explored in oysters Crassostrea gigas. Two experiments were conducted, during which oysters' valve behaviour were analyzed. Oysters, first acclimated for 10-days with the non harmful microalgae Heterocapsa triquetra (H.t.), were exposed to four microalgae mixtures at constant total concentrations of 10 x 10(3) cells ml(-1) (experiment-1) and 5 x 10(3) cells ml(-1) (experiment-2): 100% Am.; 50% A.m.-50% H.t.; 25% A.m.-75% H.t.; 100% H.t. At the end of experiment-2, [PSP](dg) were measured. At 10 x 103 cells ml(-1), the microalgal ingestion decreased (p < 0.05) with increasing [A.m.](w) but not at 5 x 10(3) cells ml(-1) (p > 0.05). The frequency of microclosures specifically increased with [A.m.](w) (p < 0.05) and the opening duration with [PSP](dg) (p < 0.0001). Oysters exhibiting the maximum increase in opening duration also exhibited the highest [PSP](dg). The results are discussed in terms of oyster physiology and origin of the behavioral response. (C) 2011 Elsevier Ltd. All rights reserved.
Mostrar más [+] Menos [-]Relationship between valve activity, microalgae concentration in the water and toxin accumulation in the digestive gland of the Pacific oyster Crassostrea gigas exposed to Alexandrium minutum Texto completo
2011
Haberkorn, Hansy | Tran, Damien | Massabuau, Jean-Charles | Ciret, Pierre | Savar, Véronique | Soudant, Philippe
The complexity of the relationships between Alexandrium minutum (A.m.) concentration in the water ([A.m.]w), Paralytic Shellfish Poisoning contamination in the digestive gland ([PSP]dg) and valve behavior was explored in oysters Crassostrea gigas. Two experiments were conducted, during which oysters’ valve behaviour were analyzed. Oysters, first acclimated for 10-days with the non harmful microalgae Heterocapsa triquetra (H.t.), were exposed to four microalgae mixtures at constant total concentrations of 10×10³cellsml⁻¹ (experiment-1) and 5×10³cellsml⁻¹ (experiment-2): 100% A.m.; 50% A.m.–50% H.t.; 25% A.m.–75% H.t.; 100% H.t. At the end of experiment-2, [PSP]dg were measured. At 10×10³cellsml⁻¹, the microalgal ingestion decreased (p<0.05) with increasing [A.m.]w but not at 5×10³cellsml⁻¹ (p>0.05). The frequency of microclosures specifically increased with [A.m.]w (p<0.05) and the opening duration with [PSP]dg (p<0.0001). Oysters exhibiting the maximum increase in opening duration also exhibited the highest [PSP]dg. The results are discussed in terms of oyster physiology and origin of the behavioral response.
Mostrar más [+] Menos [-]Sponges and sediments as monitoring tools of metal contamination in the eastern coast of the Red Sea, Saudi Arabia Texto completo
2011
Pan, Ke | Lee, On On | Qian, Pei-Yuan | Wang, Wen-Xiong
Sediments and sponges were collected from various locations along the eastern coast of the Red Sea, the Kingdom of Saudi Arabia. Total concentrations of Cd, Zn, Ag, Cu, Pb, As and Hg in the sediments were measured. Metal contamination was not significant in most of the studied sites and only one site was moderately polluted by Zn, Cu, and Pb. Sponges accumulated specific metals readily even though the metal exposure was low in the ambient environment. Contrasting interspecies differences in metal accumulation patterns were observed among the nine collected species of sponges. Significant positive correlations were found between the metal concentrations in the two species of sponges collected from the same sites. The strong ability to accumulate specific metals and the diversity of sponges that live in the Red Sea coastal areas make them a promising biomonitor of metal contamination in the areas.
Mostrar más [+] Menos [-]Regime shifts in the marine environment: The scientific basis and political context Texto completo
2011
Kraberg, Alexandra C. | Wasmund, Norbert | Vanaverbeke, Jan | Schiedek, Doris | Wiltshire, Karen H. | Mieszkowska, Nova
Regime shifts in the marine environment have recently received much attention. To date, however, few large-scale meta-analyses have been carried out due to insufficient data coverage and integration between sustained observational datasets because of diverse methodologies used in data collection, recording and archival. Here we review the available data on regime shifts globally, followed by a review of current and planned policies with relevance to regime shifts. We then focus on the North and Baltic Seas, providing examples of existing efforts for data integration in the MarBEF Network of Excellence. Existing gaps in data coverage are identified, and the added value from meta-analyses of multiple datasets demonstrated using examples from the MarBEF integrated data project LargeNet. We discuss whether these efforts are addressing current policy needs and close with recommendations for future integrated data networks to increase our ability to understand, identify and predict recent and future regime shifts.
Mostrar más [+] Menos [-]Benthic foraminifera distribution in a tourist lagoon in Rio de Janeiro, Brazil: A response to anthropogenic impacts Texto completo
2011
Vilela, Claudia Gutterres | Batista, Daniele Silva | Baptista Neto, José Antonio | Ghiselli, Renato Olindo, Jr
Rodrigo de Freitas Lagoon, located in the Rio de Janeiro City, receives several types of polluted discharges. The knowledge of the sediment microfauna correlated with heavy metal and organic matter concentrations could supply important data about the conditions of the lagoon. The benthic foraminiferal assemblage presented larger diversity and more abundant samples in the lagoon entrance than in the inner area. The Ammonia tepida – Elphidiumexcavatum foraminiferal assemblage is characterized by dwarf, corroded and weak organisms. Agglutinated species were found only near the entrance. Low abundance values and sterility of five samples in the inner area (north/northeast) can be caused by high levels of heavy metals and organic matter. A. tepida shows negative correlation with increasing heavy metals values. PAHs and coprostanol high indexes, and the absence or low presence of microfauna in samples around the lagoon margin confirm illegal flows from gas stations and domestic sewage.
Mostrar más [+] Menos [-]Fisheries mismanagement Texto completo
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.
Mostrar más [+] Menos [-]Public awareness and attitudes towards naval sonar mitigation for cetacean conservation: A preliminary case study in Fairfax County, Virginia (the DC Metro area) Texto completo
2011
Zirbel, K. | Balint, P. | Parsons, E.C.M.
The potential impacts of naval sonar on cetaceans has led to a series of court cases and statements of concern by international organizations. However, there has been no research conducted on attitudes of the general public with respect to this issue. To investigate this, a preliminary public survey was conducted in Fairfax, Virginia (the Washington, DC Metro region). The majority of the public sampled believed that naval sonar impacted marine mammals (51.3%), that the US Navy should not be exempt from environmental regulations in time of peace (75.2%), and that sonar use should be moderated if it impacts cetaceans (75.8%). Individuals who were conservative, Republican, and have served in the military were more likely to believe the Navy should be exempt from marine mammal protection regulations. In addition, expert interviews were conducted to gain opinions on the potential ramifications of the recent US Supreme Court case on naval sonar mitigation.
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