46 research outputs found

    Mine waste and acute warming induce energetic stress in the deep-sea sponge Geodia atlantica and coral Primnoa resedeaformis; results from a mesocosm study

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    There is the potential for climate change to interact with pollution in all of the Earth's oceans. In the fjords of Norway, mine tailings are released into fjords generating suspended sediment plumes that impact deep-sea ecosystems. These same deep-sea ecosystems are expected to undergo periodic warming as climate change increases the frequency of down-welling events in fjords. It remains unknown how a polluted deep-sea ecosystem would respond to down-welling because multiple stressors will often interact in unpredictable ways. Here, we exposed two deep-sea foundation species; the gorgonian coral Primnoa resedaeformis and the demosponge Geodia atlantica to suspended sediment (10 mg L-1) and acute warming (+5°C) in a factorial mesocosm experiment for 40 days. Physiology (respiration, nutrient flux) and cellular responses (lysosomal cell stability) were measured for both the coral and sponge. Exposure to elevated suspended sediment reduced metabolism, supressed silicate uptake and induced cellular instability of the sponge G. atlantica. However, combining sediment with warming caused G. atlantica to respire and excrete nitrogen at a greater rate. For the coral P. resedaeformis, suspended sediments reduced O:N ratios after 40 days, however, warming had a greater effect on P. resedaeformis physiology compared to sediment. Warming increased respiration, nitrogen excretion, and cellular instability which resulted in lower O:N ratios. We argue that suspended sediment and warming can act alone and also interact to cause significant harm to deep-sea biota, however responses are likely to be species-specific. Warming and pollution could interact in the deep-sea to cause mortality to the coral P. resedaeformis and to a lesser extent, the sponge G. atlantica. As foundation species, reducing the abundance of deep sea corals and sponges would likely impact the ecosystems they support

    Nutrition of corals and their trophic plasticity under future environmental conditions

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    202210 bcchVersion of RecordOthersResearch Institute for Future Food, The Hong Kong Polytechnic UniversityPublishe

    Molecular diversity of foraminiferal eDNA in sediments and their correlations with environmental factors from the yellow sea

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    202309 bcvcVersion of RecordOthersNational Natural Science Foundation of China; Strategic Priority Research Program of the Chinese Academy of Sciences; Wenhai Program of QNLMPublishe

    Power analysis for biomarkers in mussels for use in coastal pollution monitoring

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    Data from literature on neutral red retention time (NRRT) in lysosomes, micronucleus (MN) frequency and condition index (CI) in mussel Mytilus, especially Mytilus edulis and Mytilus galloprovincialis, were re-analyzed to ascertain their statistical power in detecting a minimum 20% spatial/temporal change in field studies. Results showed that CI largely displayed higher statistical power (>90%) than lysosomal NRRT and MN frequency (<50%), suggesting that data from the latter two biomarkers may lead to erroneous conclusions if sample size is inadequate. Samples of green-lipped mussel Perna viridis were also analyzed in Hong Kong. To achieve statistically valid power, the optimal sample sizes for monitoring lysosomal NRRT, MN frequency, CI and gonosomatic index (GSI) were determined as ≄34, ≄90, ≄16 and ≄29, respectively. Natural variability of lysosomal NRRT and MN frequency was significantly greater than CI and/or GSI in mussels, rejecting the general belief in the greater variability of higher-tiered hierarchical biomarkers. © 2009 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

    Induction, adaptation and recovery of lysosomal integrity in green-lipped mussel Perna viridis

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    Biomarkers are generally applied to detect pollution in environmental monitoring. Such biological responses should accurately reflect the stress over time in a quantitative manner. As such, the initial and maximum responses induced by stress, as well as adaptation and recovery of these biomarkers, need to be fully understood or else erroneous false-negative or false-positive may be arrived. However, most of the biomarker studies only provided information on initially induced responses under different concentrations of toxicants, while biological adaptation and recovery were poorly known. In this study, the time required for induction, adaptation and recovery of lysosomal integrity in green-lipped mussel Perna viridis upon exposure to benzo[a]pyrene was investigated over a period of 62 days. Maximum induction occurred on day 6 when lysosomal integrity was significantly reduced by 51%, and no further change or adaptation was detected thereafter. When mussels were depurated in clean seawater after 18 days of exposure to benzo[a]pyrene, a gradual recovery was observed, with lysosomal integrity returning to its background level and showing a complete recovery after 20 days of depuration. Lysosomal integrity was significantly correlated with the body burden concentrations of benzo[a]pyrene and condition index of the mussels. The relatively fast induction (6 days) and recovery (20 days) without apparent adaptation suggested that lysosomal integrity in P. viridis can serve as a good biomarker in biomonitoring, as its response is not likely to generate both false-negative and false-positive results. © 2008 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

    Seasonality of bioaccumulation of trace organics and lysosomal integrity in green-lipped mussel Perna viridis

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    Lysosomal integrity in mussels is widely used as a biomarker in coastal environments to demonstrate exposure to trace organic pollutants. However, few studies have determined the long-term influences of seasonal variations on the bioaccumulation of trace organics and subsequently altered response of lysosomal integrity in mussels. This study aimed to test three null hypotheses that (1) bioaccumulations of total polycyclic aromatic hydrocarbon (∑ PAH) and (2) total polychlorinated biphenyl (∑ PCB), and (3) lysosomal integrity as indicated by Neutral Red retention time (NRRT) in haemocytes, in the green-lipped mussel Perna viridis were not seasonally dependent. The tissue concentrations of ∑ PAH and ∑ PCB and haemocytic NRRT were determined in P. viridis in a metropolitan harbour, subtropical Hong Kong during the wet and dry seasons from 2004 to 2007. Additional information on temperature, salinity, dissolved oxygen and total ammonia nitrogen in seawater, and sediment levels of ∑ PAH and ∑ PCB, were extracted from published data and re-analyzed. Our results accepted all null hypotheses, based on the minimal seasonal influences of seawater temperature and salinity on all studied parameters, in which no significant differences between the wet and dry seasons were detected. The seasonal effect was likely outweighed by the greatly improved water quality and pollution abatement noted inside the harbour, with a gradual shift in mussel PAHs from a pyrolytic origin to a petrogenic origin. Spatially, the site east of the harbour was relatively unpolluted. The single use of NRRT in P. viridis explained 25% of the total variation of the integrated pollution patterns in seawater, sediments and mussels. The present study suggested that the dynamic change of trace organics could be reflected by the response on lysosomal integrity in P. viridis, which was recommended as a routine screening biomarker in monitoring of harbour water quality across seasons. © 2009 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex

    Influences of ammonia-nitrogen and dissolved oxygen on lysosomal integrity in green-lipped mussel Perna viridis: Laboratory evaluation and field validation in Victoria Harbour, Hong Kong

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    Lysosomal integrity in mussels has been applied as a biomarker to detect the pollution of trace organics and metals in the natural environments. However, few studies have examined the effects of water quality on the response of lysosomal integrity, in particular total ammonia-nitrogen (TAN) and dissolved oxygen (DO). This study demonstrated that high level of TAN (2.0 mg/l) and low DO (2.5 mg O2/l) could significantly reduce the lysosomal integrity in green-lipped mussel Perna viridis, respectively by 33% and 38%, whereas the mussel lysosomal integrity decreased by 70% in the combined treatment of TAN and low DO under laboratory conditions after one week. The mussel lysosomal integrity of all treatment groups could return to the control level after a three week recovery period. In the field validation in Victoria Harbour, Hong Kong during an one-year study period, lysosomal integrity in P. viridis identified the cleanest site east to the harbour, where the lowest TAN and highest DO concentrations were found. While lysosomal integrity in mussels seemed not affected by seasonal changes, approximately 40% of the variation of this biomarker could be attributable to the changes in TAN and DO in seawater. In conclusion, the response of the mussel lysosomal integrity can be confounded by both TAN and DO prevailing in the natural environments and thus caution must be exercised in relating the observed changes in lysosomal integrity to any specific pollutant in coastal water quality monitoring studies. © 2008 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex
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