Interseasonal variability in biomarkers of exposure in fish inhabiting a southwestern Australian estuary

Abstract

The Swan-Canning Estuary, in southwestern Australia, undergoes distinct seasonal changes, with freshwater discharge predominant in the winter (wet) season and low flow with high salinity predominant in the dry summer season. To investigate seasonal variability in biomarkers of exposure in fish, black bream (Acanthopagrus butcheri) were collected from seven sites in the Swan-Canning Estuary in winter 2000 and in summer 2001. No interseasonal or intersite differences in serum sorbitol dehydrogenase concentration were found, indicating the measured mixed-function oxygenase (MFO) enzymes were not influenced by liver damage. The ethoxyresorufin-O-deethlyase (EROD) activity of the postspawning females was higher in summer than in winter but was significantly lower than that in males in both seasons, suggesting estradiol suppression in females. Sexual differences in ethoxycoumarin-O-deethylase (ECOD) activity were not evident in either season. Both EROD and ECOD activities and polycyclic aromatic hydrocarbons (PAH) biliary metabolites had significantly different patterns of induction between seasons. The ratio of naphthalene-type to benzo(a)pyrene-type biliary metabolites was significantly higher in summer, indicating the sources of petroleum hydrocarbons were petrogenic compared to in winter, when the source was a mixture of pyrogenic and petrogenic PAHs. There was no upstream or downstream gradient of response in any biomarker in either season, demonstrating that there were multiple sources of contaminant input into the estuary. Although winter biomarker levels were triggered by the discharge runoff from major roads and drains, summer biomarker levels appear to have been related to recreational boating use on the estuary.

The influence of seasonality, fish size and reproductive status on EROD activity in Plagioscion squamosissimus: Implications for biomonitoring of tropical/subtropical reservoirs

“…2A). Webb and Gagnon (2002) and Webb et al (2005), found a similar pattern in the Swan-Canning river, Western Australia, in which males at all sites, had a higher EROD activity than female fish. In the present study, male croaker had significantly higher EROD activity level than the females, most likely due to reproductive activity, supporting the finding by Hodson et al (1991) that the reproductive status can significantly affect EROD activity in fish.…”

Evaluation of PAH Metabolites in Bile of Common Carp,Cyprinus carpioL. with Fixed Wavelength Fluorescence in a Field and Laboratory Study

“…This method is also useful to examine the ratio between types of PAHs. The ratio of PAH metabolites can be used to indicate the origin of PAH contamination (6,19,25,26). The FF analysis of bile measures groups of PAH metabolites, with the naphthalene-type comprised mainly of two-ring structures, the phenanthrene-type mainly three-ring structures, pyrene-type mainly four-ring structures, and the B(a)P-type mainly five-ring structures (4).…”

“…As many fish species are highly mobile, measurement of biomarkers is often a more reliable method for assessing exposure to PAHs than measuring PAHs in the sediment where the fish were captured, and bioavailability is taken into account (5). Also, fish can metabolize PAHs to form reactive metabolites, which subsequently can bond covalently as adducts to cellular macromolecules, such as DNA, RNA, and proteins (6).…”

Knowledge gaps in ecotoxicology studies of marine environments in Pacific Island Countries and Territories – A systematic review

“…Aus: Baker et al, 2016;Duarte et al, 2017;Fu et al, 2017b;Gagliano et al, 2011;Gagnon and Rawson, 2016;Goodall et al, 2016;Hassell et al, 2016;Humphrey et al, 2007;Mai and Fotedar, 2017;Shaw et al, 2004;Webb and Gagnon, 2013;Webb et al, 2005NZ: Chandurvelan et al, 2015 Biotransformation Phase I (Cytochrome P450) Transformation of hydrophobic chemicals via oxidation, reduction and hydrolysis to more polar products.…”