Local mussels, Perna viridis, were transplanted from a relatively clean site to various polluted sites in Hong Kong. After a 30-day field exposure, different antioxidant parameters including glutathione S transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), NADPH DT-diaphorase (DT-d), glutathione (GSH) and lipid peroxidation were quantified, and tissue concentrations of benzo[a]pyrene (B[a]P) as well as a total of five polycyclic aromatic hydrocarbons (PAHs) with potential carcinogenicity were determined for individual mussels. Results indicated that: (1) tissue concentrations of B[a]P and total PAHs from the same site were highly variable; (2) gill SOD, DT-d and lipid peroxidation showed no response to tissue pollutants: (3) the majority of the antioxidant parameters were induced by increasing tissue pollutant concentrations; and (4) amongst the various parameters, oxyradical scavenger GSH [ best correlated with tissue concentrations of pollutants.

Relationships between tissue concentrations of polycyclic aromatic hydrocarbons and antioxidative responses of marine mussels, Perna viridis

Tesis de ,aestria presentadas en la facultad de ciencia y tecnologia, Universidad Pedagogica Nacional.

Tesis de maestria

Organic ultraviolet (UV) filters are widely used in personal care products and occur ubiquitously in the aquatic environment. In this study, concentrations of seven commonly used organic UV filters were determined in seawater, sediment and five coral species collected from the eastern Pearl River Estuary of South China Sea. Five compounds, benzophenone-1, −3, and −8 (BP-1, −3, and −8), octocrylene (OC) and octyl dimethyl-p-aminobenzoic acid (ODPABA), were detected in the coral tissues with the highest detection frequencies (>65%) and concentrations (31.8 ± 8.6 and 24.7 ± 10.6 ng/g ww, respectively) found for BP-3 and BP-8. Significantly higher concentrations of BP-3 were observed in coral tissues in the wet season, indicating that higher inputs of sunscreen agents could be attributed to the increased coastal recreational activities. Accumulation of UV filters was only observed in soft coral tissues with bioaccumulation factors (log10-values) ranging from 2.21 to 3.01. The results of a preliminary risk ass...

Occurrence, Distribution, and Fate of Organic UV Filters in Coral Communities

One prominent hypothesis regarding climate change and scleractinian corals is that thermal stress compromises immune competence. To test this hypothesis we tracked how the immune defenses of bleached, apparently healthy and yellow band disease (YBD) diseased Montas- traea faveolata colonies varied with natural thermal stress in southwestern Puerto Rico. Colonies were monitored for 21 mo from the peak of the bleaching event in October 2005 to August 2007. Since sea surface temperature was significantly higher in summer and fall 2005 than 2006, year of collection was used as a proxy for temperature stress, and colony fragments collected in 2005 were compared with those collected in 2006. Mortality rate was high (43% overall) and all colonies (except one) either died or became infected with YBD by August 2007. YBD-infected tissue did not bleach (i.e. expel zooxanthellae) during the 2005 bleaching event, even when healthy tissue of these colonies bleached. Immune activity was assayed by measuring prophenoloxidase (PPO), peroxidase (POX), lysozyme-like (LYS) and antibacterial (AB) activity. Immune activity was variable between all coral samples, but there was a significant elevation of PPO activity in bleached colonies collected in 2005 relative to apparently healthy and YBD-diseased corals in 2006. In YBD-diseased colonies, LYS and AB activity were elevated in both healthy and infected tissue, indicating a systemic response; activity levels in these colonies were higher compared to those that appeared healthy. In both these immune parameters, there was a trend for suppression of activity in corals that were bleached in 2005. These data, while complicated by between-genet variability, illustrate the complex interaction between disease and temperature stress on immune function.

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Immune defenses of healthy, bleached and diseased Montastraea faveolata during a natural bleaching event.

Cu/Zn- and Mn-superoxide dismutase (SOD) from the copepod Tigriopus japonicus: Molecular cloning and expression in response to environmental pollutants

Components of the cytochrome P 450 monooxygenase system (MFO) and antioxidant enzymes were investigated in the coral Montastraea faveolata exposed to the organic contaminant benzo( a )pyrene (B( a )P). For bioassays the corals were exposed to increasing concentrations of B( a )P (0.01 and 0.1 ppm) for 24 and 72 h, with water renewal every 24 h. Enzymatic activity of catalase (CAT), superoxide dismutase (SOD) and glutathione S-transferase (GST) were measured in host (polyp) and hosted (zooxanthellae) cells. NADPH cytochrome c reductase activity and contents of cytochrome P 450 and P 420 were only measured in the polyp. Antioxidant enzymes CAT and SOD in polyps and zooxanthellae and GST in polyps increased significantly at the highest concentration and maximum time of exposure. Cytochrome P 420 was found in all colonies, and the cytochrome P 450 content was greatest in the colonies from the highest concentrations of contaminant. NADPH cytochrome c reductase activity and the concentration of pigments did not vary between treatments. This is the first report of the induction of both detoxifying mechanisms, the MFO system and antioxidant enzymes on acute exposure to an organic contaminant in the reef-constructing coral species M. faveolata .

E. García

Papers

Induction of mixed-function oxygenase system and antioxidant enzymes in the coral Montastraea faveolata on acute exposure to benzo(a)pyrene