Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...

Contaminants in Tissue of o Fish and Crabs Collectedin the Gladstone Area6. Are the levels of contaminants in fish andknown to be associatedwith reportedecotoxicologicaleffects?crab tissue6.1.IntroductionWhere residues were identified as being significantly elevated at Gladstone G sites compared toreference sites or were significantly associated with fishor crab health issues, results werecompared to data retrieved from the Environmental Residue and Effects E Database (ERED,http://el.erdc.usace.army.mil/ered/). If there were no significant differences between measuredmetal concentrationsof diseasedd and healthy fish, or Gladstone Harbour H andd reference sites thenthese metals and metalloids could be discounted as contributing too the fish disease in GladstoneHarbour.6.2.Metal Residues in the t Hepatopancreas of Mud CrabsThe concentration of aluminium and selenium was found to be significantly higher in diseasedcrabs than healthy crabs (Section4.1). No data for toxicological effects basedd on aluminium orselenium concentrations in crab hepatopancreas was found in the Environmental Residue andEffects Database, so the elevated concentrations of these metals and metalloids could not beassessed in terms of their potential effects.6.3.Metal Residues in the t Gillsand Liver of BarramundiMeasured concentrations of arsenic, cadmium, iron andzinc in thee liver of barramundi were foundto be significantly higher in the group of samples collected for at least one tripp in the GladstoneHarbour samples, particularly in the t Port DevelopmentArea (Figure 17).6.3.1.ArsenicArsenic was detected in liver tissue at concentrations ranging between 0.29 and 6.37 mg/kg wetweight at Gladstone and reference sites, with the highest level of arsenic a (6.37 mg/kg) beingmeasured in a samplefrom the Bundaberg(reference) site. LD50ss (concentrations lethal to 50% ofthe test organisms) were associated with liver concentrations of arsenic between 5.69 mg/kg wetweight (Mozambiquetilapia - Oreochromis mossambicus) and 122.8 mg/kg (Green sunfish -Lepomis cyanellus) (US Army Corp Engineers & USEPA, 2011) (Table 12). Of the 45 barramundiliver samples collected in the program, only two had arsenic concentrations above the lowestrecorded effects concentrations and the vast majority were significantly lower. The only chroniceffect noted for arsenic concentrations was at a No Observed Effect Doss (NOED) of 11.6 mg/kgwet weightin bluegill Lepomis macrochirus.This is nearly double the t maximum concentration ofliver arsenic measured in this study, therefore it is unlikely that arsenic residues in barramundilivers would cause harmful effects to fish.There weree no data on immunosuppressioneffects in fish due to arsenic a in the Poulsen andEscher (2012) report.Page 25