First report of intersex in a lutjanid: the goldband snapper Pristipomoides multidens.

This is the first report of intersex in a lutjanid species, the goldband snapper Pristipomoides multidens, in which the gonads of a male fish contain multifocal oocytes scattered among testicular tissue. The incidence rate of intersex was low (<1.0%), with oocytes observed in the testes of only two of 206 male fish examined. The capacity for P. multidens to develop an intersex condition suggests that future monitoring of this species should include histological analysis of gonads.

Benthic macroinvertebrate assemblages in remediated wetlands around Sydney, Australia.

To investigate potential high organisational level impacts of persistent organic pollution in the wetlands in the Sydney Olympic Park (SOP) remediated site, the benthic macroinvertebrate assemblages of seven wetlands within SOP and two off-site reference wetlands were examined. Sediment cores were collected, stained and preserved from each study site and the macroinvertebrates identified to the appropriate taxonomic level (Class, Order, Family, Subfamily). Data were analysed for taxon richness and macroinvertebrate abundance and multivariate techniques were used to identify chemical/physical characteristics of the sediment, which were important influences on the differences in the assemblage between study sites. Macroinvertebrate abundance was highly variable between study sites and taxon richness was low across all sites. Oligochaetes, nematodes, ostracods and chironomids were the most common taxa found and were the most important in influencing differences between the macroinvertebrate assemblages among the study sites. Sediment grain size and chemical characteristics of the sediments (ΣPAH, ΣPCB, TCDDeq and heavy metal concentrations) were important in separating the study sites based on taxon richness and abundance. Canonical correspondence analysis separated the macroinvertebrate assemblages at newly two created wetlands from those at other study sites including the urban reference sites. Increased sediment POP contamination (particularly as measured TCDDeq and ΣDDT concentrations) is a likely contributor in excluding pollution sensitive taxa and, therefore, alterations to benthic macroinvertebrate assemblages. Further, the influence of TOC suggests the significance of catchment inputs in contributing to changes in macroinvertebrate assemblage. The SOP remediation led to the establishment of wetlands with benthic communities representative of those expected in urban wetlands.

Bioactivity of POPs and their effects in mosquitofish in Sydney Olympic Park, Australia.

The site of the 2000 Olympic Games (Sydney Olympic Park (SOP), Sydney, Australia) was contaminated by persistent organic pollutants (POPs) prior to remediation in the 1990s. This study investigates the bioactivity of POPs in the sediment and water of wetlands across SOP by in vitro 2,3,7,8-TCDD equivalence (TCDDeq) measurement (H4IIE cell line bioassay). Further, it examines whether disturbance of these sediments is likely to mobilise ligands for this receptor into the water column. Exposure to aryl hydrocarbon receptor (AhR) ligands was measured in vivo using hepatic cytochrome P4501A (CYP1A) induction (EROD) in the mosquitofish (Gambusia holbrooki). Aqueous TCDDeq ranged from 0.013 to 0.057 pM in SOP wetlands which was significantly (p<0.05) less that in urban reference sites. These concentrations were not correlated to physical or chemical characteristics of the wetlands. In the sediments, TCDDeq ranged from 0.0016 to 7.06 microg/kg and these were not significantly (p>or=0.05) different to that measured in urban reference sites. Simulated disturbance of small quantities of sediment in water samples significantly (p<0.05) increased the levels of TCDDeq measured in the water. Sediment TCDDeq was correlated to sediment SigmaPAH concentration in 2006 and sediment SigmaPCB, SigmaDDT concentrations and fine sediment grain size in 2005. While fish at one SOP wetland had hepatic EROD activity elevated above the estimated basal level for this species, these were at the lower end of the range measured in urban impacted, non-remediated wetlands. EROD activity was positively correlated with both the sediment SigmaPCB load and aqueous TCDDeq. Increased catchment size was correlated with increased EROD activity suggesting an even spread of POPs throughout the residential areas of the Sydney metropolitan area. The concentration of bioactive POPs in the wetlands of SOP is therefore low relative to urban reference sites demonstrating the ongoing success of the remediation program.

Contamination and screening level toxicity of sediments from remediated and unremediated wetlands near Sydney, Australia.

The present study assessed contamination and toxicity of sediments from seven remediated and remnant wetland sites within Sydney Olympic Park, Australia, and four unremediated sites adjacent to its boundary using chemical analysis and a luminescent bacterial biosensor assay (Escherichia coli). Concentrations of metals (Pb, Cr, Cu, Ni, Zn, Cd, and As) and persistent organic chemicals (DDT and its metabolites, dichlorodiphenyldichloroethane and dichlorodiphenyldichloroethylene; polycyclic aromatic hydrocarbons; polychlorinated biphenyls; and polychlorinated dibenzo-p-dioxins and dibenzofurans) in sediments and their pore-water samples were determined. Zinc concentrations were the highest of the metals in the sediments (84-618 mg/kg), and at eight sites, metal concentrations in sediments exceeded the Australian ecological trigger values for Pb, Zn, and Ni. Concentrations of organic contaminants in the sediments exceeded the trigger values at all 11 sites for DDTs, at 6 sites for polycyclic aromatic hydrocarbons, and 5 sites for polychlorinated biphenyls. Sediment samples from the four unremediated sites outside the Sydney Olympic Park had dioxin concentrations greater than 200 pg (toxic equivalency per gram). The same four sites were identified as contaminated in pore-water toxicity tests with the luminescent biosensor, generally consistent with the bioavailable fractions of the contaminants (pore-water and Tenax extraction data), as well as dioxin levels, in the sediments. Preliminary toxicity identification and evaluation tests of the pore water from the four sites outside the park demonstrated that organic contaminants were the main cause of toxicity to E. coli, with no evidence that metals contributed to the toxicity of the pore water.

Distribution of inorganic and organic contaminants in sediments from Sydney Olympic Park and the surrounding Sydney metropolitan area.

Organic and inorganic contamination was assessed for sediments from wetlands and water bodies within the Sydney Olympic Park (SOP, remediated sites) and its surroundings (unremediated sites) and urban reference sites in the Sydney Basin. Among the seven elements analysed (As, Cd, Cr, Cu, Pb, Ni and Zn), Zn concentrations were the highest, followed by Pb, Cu and Cr in the sediments of SOP. Significantly higher concentrations (p < 0.05) of DDTs were found in sediments of the Homebush Bay and Parramatta River sites compared with the urban reference sites, mainly due to past manufacturing of DDT in the Homebush Bay area. However, no significant differences (p > 0.05) in concentrations were found for polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) as well as DDTs between sediments from SOP and the urban reference sites. Source indicators suggest that PAHs in the sediments originated from combustion processes. Two distinct groups of dioxin profiles were observed within SOP and its surroundings. Levels of dioxins were more than 100 pg WHO-TEQ/g dry weight of sediment at five sites adjacent to the SOP boundaries. Based on the findings of the chemical profiles of the contaminants, the remediated sites in SOP can be regarded as similar to the urban reference sites within the Sydney Basin, while the adjacent unremediated sites have higher concentrations, especially of dioxins, that could still affect organisms in the aquatic environment.

Skeletal morphology and maturation of male Gambusia holbrooki exposed to sewage treatment plant effluent.

Sewage effluent has been identified as a major source of endocrine disrupting chemicals (EDCs) in the aquatic environment. The modified hemal spines (modified skeletal structures important in reproduction) of mosquitofish, Gambusia spp. have been shown to be under androgenic control and to be affected by exposure to estrogen. The current study aimed to investigate the effects of two sewage treatment plants (STPs) in Sydney, Australia on the morphology of hemal spines in populations of Gambusia holbrooki and on the ability of the fish to reach sexual maturity. The effluent from the two STPs had different effects on the hemal spines of males. At St. Marys differences in hemal spine morphology between fish upstream and downstream of the STP were not attributable to effluent from the STP. At Quakers Hill, results suggest that the effluent is generally estrogenic to G. holbrooki. There was a decrease in the proportion of males that were morphologically mature downstream of both STPs indicating potential population level effects that were associated with the presence of the STPs.

The effect of 17beta-estradiol on the development of modified hemal spines in early-life stage Gambusia holbrooki.

The morphologic development of the gonopodium of male mosquitofish, Gambusia holbrooki, is essential for proper reproductive function and has previously been used as a biomarker for the presence of endocrine-disrupting chemicals (EDCs) in freshwater systems. The development of the gonopodium is accompanied by the modification of the hemal spines on the 14th, 15th, and 16th vertebrae. These form an anchor for the movement of the gonopodium, and their normal development is therefore critical. This development is under hormonal control. It has been hypothesized that the modification of the hemal spines may be used as an end point for understanding the effects of exposure of early-life stage fish to EDCs and to add to the understanding of the differential sensitivities of different life stages. Larval fish were exposed to concentrations (0, 20, 100, and 500 ng/L) of 17beta-estradiol (E(2)) in two experiments using a flow-through system for 8 and 12 weeks. There was a general delay in the development of the three hemal spines when exposed to high concentrations of E(2). However, this delay was not observed for all end points on a particular spine nor across all spines. Fish examined at 8 weeks postpartum showed a more extensive delay at high concentrations than those examined at 12 weeks postpartum, suggesting that later in the life cycle, high levels of exogenous E(2) may be overcome by increasing levels of endogenous androgen. There was a decrease in the number of phenotypic male fish present in the 500-ng/L treatment at 12 weeks postpartum and an apparent decrease in the degree of sexual differentiation at high levels of E(2) exposure. The results suggest that effects of EDC exposure begin very early in a fish's life cycle.