Contaminant pathways in Port Curtis: Final report - OzCoasts

More documents

Recommendations

Info

Contaminant pathways in Port Curtis: Final report7: Antioxidant enzymes as biomarkers(Photo courtesy of Leonie Andersen)Figure 7.2. Individual bags of oysters attached to buoys ready for deploymentA laboratory bioassay experiment (Figure 7.3) was undertaken in order todetermine the effect of dissolved copper exposure on biomarker response(CAT, LPO, GSH and GST) in oysters. Full details of these experiments may befound in the report by Andersen et al. (2006). Briefly, the experiment involved acopper exposure phase (21 days) and a depuration phase (7 days). Oysterswere maintained in aerated tanks containing 10 L filtered sea water at 25°C,with a 12:12 h light:dark cycle. Each tank contained typically 26 oysters. Theoysters were fed three times a week with 200 mL of cultured marine algae,Nanochloropsis occulata.(Photo courtesy of Leonie Andersen)Figure 7.3. Oysters in treatment tanks in copper bioassay83
Contaminant pathways in Port Curtis: Final report7: Antioxidant enzymes as biomarkersOysters were acclimated for 7 days in clean sea water in the laboratory prior tothe start of the experiment. The seawater treatments were prepared by spikingfiltered seawater (background copper concentrations: ~3 µg/L) with inorganiccopper to attain final nominal added copper concentrations of 0, 3.75, 7.5, 15and 30 µg/L in addition to the background concentrations. Each treatment wasreplicated five times. Treatment water was renewed three times weekly. Samplesfor tissue metals and biomarker analysis were taken on days: 2, 5, 8, 12, 15, 23and 28. Ten oysters were used for biomarker analysis and six oysters (twooysters pooled to form one composite) were sampled for metal analysis.After removal from the field or from the laboratory treatment tanks, oysters weredissected and gills and hepatopancreas removed then placed into centrifuge tubesand immediately frozen on dry ice. Samples were then stored frozen in liquidnitrogen (-80 ºC) before transportation on dry ice to City University, Hong Kong,for biomarker analysis. Biomarker analysis in both the dissected gill andhepatopancreas samples was carried out using a method based on theprocedures developed by Cheung et al. (2001).Oysters collected for metal analysis were frozen whole until processing. Thesamples were thawed overnight in a refrigerator, then the soft tissue extractedfrom the shell and blotted dry. The tissues of the two replicate oysters from eachtreatment tank were pooled to form one composite sample, placed in polyethylenejars, and frozen until analysis at Griffith University, Queensland. The sampleswere analysed using inductively coupled plasma mass spectrometry (ICP-MS).Preparation and chemical digestion of oyster tissues followed a method similar tothat used by Andersen et al. (1996).7.3 Results and discussion7.3.1 Oyster metal concentrationsTissue metal concentrations are summarised in Table 7.1. Metal concentrationsdisplayed very few convincing trends with time. The tissue concentrations ofaluminium, copper, zinc and chromium after 29 days of deployment weresignificantly greater than those at Site 2 (Table 7.1). Conversely, concentrationsof arsenic and nickel were significantly more elevated in oysters from Site 2.84
Page 4:
Contaminant pathways in Port Curtis
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56: Contaminant pathways in Port Curtis
Page 105: Contaminant pathways in Port Curtis
Page 143: Contaminant pathways in Port Curtis
show all

Contaminant pathways in Port Curtis: Final report - OzCoasts

Create successful ePaper yourself

Delete template?

Save as template?