Jing-O Cheng

Chronic exposure of 2,2′,4,4′-tetrabromodiphenyl ether (PBDE-47) alters locomotion behavior in juvenile zebrafish (Danio rerio)

In the present study, we used zebrafish (Danio rerio) as a model to address possible effects of chronic exposure of polybrominated diphenyl ether (PBDE) flame retardants on locomotion behavior, body size, and gonad development in fish. Zebrafish were fed food dosed with PBDE-47 (control, solvent control, low, medium, and high dose groups) from 21 days post hatch (dph) to 90 dph. Fish locomotion parameters, including maximum swimming speed, total distance moved, and percent time active, were assessed using a video-based animal movement analysis system. At the end of the exposure, all fish were euthanized for length and weight measurement, and then subjected to either whole fish histological analysis or tissue PBDE-47 measurement. Survival, body size, and gonad histology were similar between the five groups. However, both total swimming distance and percent time active were negatively correlated with tissue PBDE-47 concentration and were significantly lower in the high dose group. Tissue levels of PBDE-47 in the exposed fish were comparable to that reported in previous field studies. In summary, this study showed that developmental exposure of PBDE-47 at an ecologically relevant level altered locomotion behavior without affecting body size or gonad development of zebrafish.

Air-water exchange fluxes of polycyclic aromatic hydrocarbons in the tropical coast, Taiwan.

Air-water exchange fluxes of polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in air and water samples from two sites on the Kenting coast, located at the southern tip of Taiwan, from January to December 2010. There was no significant difference in the total PAH (t-PAH) concentrations in both gas and dissolved phases between these two sites due to the less local input which also coincided to the low levels of t-PAH concentration; the gas and dissolved phases averaged 1.29±0.59 ng m(-3) and 2.17±1.19 ng L(-1) respectively. The direction and magnitude of the daily flux of PAHs were significantly influenced by wind speed and dissolved PAH concentrations. Individual PAH flux ranged from 627 ng m(-2) d(-1) volatilization of phenanthrene during the rainy season with storm-water discharges raising dissolved phase concentration, to 67 ng m(-2) d(-1) absorption of fluoranthene during high wind speed periods. Due to PAH annual fluxes through air-water exchange, Kenting seawater is a source of low molecular weight PAHs and a reservoir of high molecular weight PAHs. Estimated annual volatilization fluxes ranged from 7.3 μg m(-2) yr(-1) for pyrene to 50 μg m(-2) yr(-1) for phenanthrene and the absorption fluxes ranged from -2.6 μg m(-2) yr(-1) for chrysene to -3.5 μg m(-2) yr(-1) for fluoranthene.

Assessing the effects of polychlorinated biphenyls (Aroclor 1254) on a scleractinian coral (Stylophora pistillata) at organism, physiological, and molecular levels.

Polychlorinated biphenyls (PCBs) are a group of widespread contaminants, and accumulation of PCBs has been observed in corals in the field. However, the toxic effects of PCBs on corals have not been investigated. In this study, we tested short and long term toxicity of Aroclor 1254, a commercial PCB mixture, on the scleractinian coral Stylophora pistillata. Coral nubbins were incubated in either control seawater or seawater dosed with PCBs (approximately 300ng/L) for 96h. The effect of PCB exposure on coral gene expression at 4h post exposure was tested with the suppression subtractive hybridization (SSH) and quantitative PCR methods. Photosystem II activity of the zooxanthellae was measured at 96h. After the exposure, nubbins were moved into clean seawater and their survival and growth were observed for another 50 days. All nubbins survived during the exposure and the following 50-d recovery period. Photosystem II activity and coral growth were not affected by PCB exposure in this study. Fifty-four clones were sequenced for gene expression analysis, and 15% of these sequences were identified, including genes involved in general stress response, peptide metabolism, cellular receptor, cytoskeleton organization, membrane trafficking, and oxidative stress response. However, the quantitative PCR did not show significant difference in the five selected genes. In conclusion, acute exposure of S. pistillata to Aroclor 1254 at 300ng/L did not affect coral survival, photosynthesis or growth but may alter the expression of certain genes involved in various important cellular functions. The nubbin technique proved to be an efficient approach to simultaneously characterize the impact of PCBs on the corals at multiple biological levels.

Endocrine disrupting effects of domestic wastewater on reproduction, sexual behavior, and gene expression in the brackish medaka Oryzias melastigma

The objective of this study was to investigate the endocrine disrupting effects of domestic wastewater on fish using the brackish medaka Oryzias melastigma as the animal model. Estuarine water samples were collected from Sihchong Creek and Baoli Creek estuaries, Taiwan, in March of 2012 to assess the whole effluent toxicity (WET) of domestic wastewater produced by the local residents and tourists. Chemical analysis detected various pharmaceuticals and personal care products (PPCPs) in the field water samples. Some of these PPCPs are endocrine disrupting chemicals. In the laboratory-based bioassay, breeding pairs were exposed to the water samples (Sihchong, Baoli, and control) for 21 days. Cumulative number of eggs spawned was significantly higher in the Sihchong group. While fish swimming activity was not affected, sexual behavior of the male fish was significantly induced in both Sihchong and Baoli groups. Male and female gonad histology was not affected. Expression level of biomarker genes CYP1A1, HSP70, and VTG was significantly induced in the Sihchong group. This study indicates that the mixture of contaminants contained in the estuarine water may cause endocrine disrupting effects in fish.

Concentration and Partitioning of Polycyclic Aromatic Hydrocarbons in the Seawater of Houwan, Taiwan

This study involved determining temporal variation in polycyclic aromatic hydrocarbon (PAH) concentrations in Houwan seawater. Factors causing the variability in PAH concentrations and partitioning of PAHs between the particulate and dissolved phases were investigated. The results showed that the total concentrations of PAHs in the dissolved phase and particulate phase ranged from 0.46 to 3.86 ng/L and 0.04 to 1.8 ng/L, respectively. The Houwan seawater is less contaminated with PAHs than the adjacent seawater. Sediment resuspension was likely the main reason for the high variability observed in PAH concentrations. This study also found a linear relationship between logKoc and logKow of PAHs. The observed high partition coefficients in this study may be explained by the presence of soot-like carbon, a strong adsorbent, in the suspended particulate matters.

Effect of the UV-filter benzophenone-3 on intra-colonial social behaviors of the false clown anemonefish (Amphiprion ocellaris)

The UV-filter benzophenone-3 (BP-3) is widely used and is environmentally stable, lipophilic, and bioaccumulative. Previous in vitro and in vivo studies have shown that BP-3 can cause endocrine disrupting effects. However, little information is available on its ecotoxicity on coral reef fish. Agonistic behavior, which is regulated by the endocrine system, is crucial to the social structure of some coral reef fish species. Endocrine disruptors may disturb fish agonistic behavior and social interactions. In this study, we tested whether chronic BP-3 exposure can affect social behaviors in coral reef fish. Juvenile false clown anemonefish (Amphiprion ocellaris) were exposed to BP-3 via diet (0 and 1000 ng/g food) for 90 d. Through the experiment, each tank was videotaped and behavioral indicators of social status, including threatening, attacking, and submissive behaviors were quantitatively analyzed from the videos. Survival and growth were not affected by the BP-3 exposure except that the body weight of the dominant fish was higher in the BP-3 group. Social rankings were not changed by BP-3. Intra-colonial social behaviors were significantly affected only by rank but not by the BP-3 exposure. Our results suggest that BP-3 at environmental levels may not cause significant harm to social behavior of coral reef fish. However, more research is needed to better understand the behavioral effects of BP-3 in fish.

Occurrence of PBDEs in surface sediments of metropolitan rivers: Sources, distribution pattern, and risk assessment

Sources, concentrations, and ecological risk of polybrominated diphenyl ethers (PBDEs) were investigated in surface sediments from 33 stations in Danshui River basin (Taiwan) in 2015. High spatial variation in total PBDEs (Σ19PBDEs) in sediments was found ranging from 2.3 to 10,490 ng g-1 dw. The effects of the physicochemical characteristics, total organic carbons (TOC) and grain size of sediments on the levels and distributions of PBDEs were investigated. Significant linear correlations were observed for PBDE concentrations with TOC (r2 = 0.45, p < 0.01) and fine sediment fraction (grain size <1 mm; r2 = 0.2, p < 0.05). Spatial distributions of Σ19PBDEs showed that sediment samples were likely impacted by point source inputs. BDE209 was the dominant congener, accounting for 77.5%-99.9% of the Σ19PBDEs in sediments suggested that commercial deca-BDE mixtures are the major sources of PBDEs in Danshui River basin. Regarding ecological risk estimation, high molecular PBDEs pose a high risk quotient (RQ > 1) to sediment dwelling organism along the 33 sampling stations, suggesting that penta-BDEs and deca-BDE are the major ecological risk drivers in the Danshui River basin.

Persistent organic pollutants in Antarctic notothenioid fish and invertebrates associated with trophic levels

Notothenioid fish and invertebrate samples from Antarctica were collected in the austral summer of 2009, and analyzed for persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polybrominated diphenylethers (PBDEs), as well as δ13C and δ15N stable isotopes for trophic level determination. In this study, the POP levels in the Antarctic biota samples were found to be ranked in the following order: OCPs > PAHs >> PBDEs. The POP levels in notothenioid fish and krill correlate to trophic levels; however, the POP concentrations in intertidal benthic invertebrates are higher than in notothenioid fish implying that specific biogeochemical factors may affect bioaccumulation in the Antarctica ecosystem. Biomagnification of POPs may have a smaller role than bioconcentration in Antarctica environment. In addition to the source, transport, exposure, and absorption for each group of POPs in the short food chain in Antarctica, the biological variation among species, interaction habitats, diet and metabolism are also factors for future studies on contaminant bioaccumulation.

Concentration of Polycyclic Aromatic Hydrocarbons in the Seawater of Houwan Affected by the Grounding of the Chemical Tanker W-O Budmo

On 8 August 2009, a German chemical tanker known as the W-O Budmo ran aground near Checheng, Pingtung, spilling oil into the Houwan area. Polycyclic aromatic hydrocarbons (PAHs), which have acute toxicity and sublethal effects to aquatic organisms, are major components found in oil and therefore there was great cause for concern. Concentrations of PAHs were monitored in seawater and sediments at several sampling sites near Houwan to evaluate the potential environmental impact caused by this incident. Two sampling sites (C and D) were established near the grounding location to capture the immediate spread of PAHs. Two other sites (B and E) were established 0.5 km north and south of the tankers position to monitor the potential spread of pollutants. Site A was the water inlet of the National Museum of Marine Biology and Aquarium (NMMBA) to monitor seawater quality input to NMMBA. The reference station, site F, was at Wanliton. Samples were collected from the surface seawater (＜5 m) of Houwan from 10 August to 29 December 2009. The results indicated that the total PAH concentrations gradually decreased to the background levels at the sites where the W-O Budmo ran aground. Principal component analysis (PCA) of the seawater samples in this study was used to compare the PAH compound patterns of the oil spilled from the W-O Budmo. The results indicated that seawater at sites B, C, and D were affected by oil spilled from the W-O Budmo during the first week of the incident. One week after the incident, the PAH compound patterns at sites B, C, and D were similar to those of other sites, and were within environmental background levels from a previous study within the study area prior to the oil spill. Total PAH concentrations measured in surface sediment samples collected from inter-tidal areas were much lower than that previously reported in the same area, indicating that no oil residue was transported to the sediments in the inter-tidal areas. This study suggests that total PAH concentrations in the Houwan coastal area were not seriously affected by the grounding of the chemical tanker W-O Budmo.

Extraction of Polycyclic Aromatic Hydrocarbons from: A Sediments Comparison between Accelerated Solvent Extraction and Soxhlet Extraction Techniques

The methods of simultaneous extraction of polycyclic aromatic hydrocarbons (PAHs) from field sediments using Soxhlet extraction and accelerated solvent extraction (ASE) were established, and the extraction efficiencies were systemically compared from procedural blank, limits of detection, spiked method recovery, and other factors. The results showed that the values obtained in this study were comparable with the values reported by other studies. In the respects of method recovery and analysis parameter there were no significant differences between ASE and Soxhlet methods for the extraction of PAHs. In this study, under the ASE operational parameters of 100 ℃, 1500 psi, and 5 minutes, and extraction solvents of acetone and hexane, it receives a reliable extraction effectiveness compared to Soxhlet extraction. Overall, considering solvent consumption and extraction time, ASE is preferable to Soxhlet extraction.