Evaluation of population‐level ecological risks of dioxin‐like polychlorinated biphenyl exposure to fish‐eating birds in Tokyo Bay and its vicinity

Abstract

Population-level assessments of the ecological risks of dioxin-like polychlorinated biphenyl (PCB) exposure to fish-eating birds in Tokyo Bay and its vicinity were performed to judge the need for risk management measures to protect aquatic wildlife from dioxin-like PCB contamination. Egg mortality risk and changes in the population growth rate (lambda) in relation to the contamination levels of dioxin-like PCBs in eggs of gray heron (Ardea cinerea), great cormorant (Phalacrocorax carbo), osprey (Pandion halieaetus), and kingfisher (Alcedo atthis) were determined by integrating the results of exposure analysis, effect analysis, and a life-history model for each species. The egg mortality risks for the gray heron, great cormorant, osprey, and kingfisher populations were calculated to be 5.8, 6.8, 12, and less than 1%, respectively. The estimated lambda for those populations were calculated to be 1.061, 1.405, 1.024, and 1.131, respectively. The percentage changes in lambda for those populations were estimated to be 1.2, 2.0, 1.6, and less than 1%, respectively. Our results implied that the levels of dioxin-like PCBs observed in the Tokyo Bay area alone would not have significant population-level effects on the fish-eating bird populations. It is concluded that along with the trend toward decreasing dioxin and dioxin-like PCB levels in Tokyo Bay, no urgent need exists for risk-reduction measures to protect fish-eating bird populations against dioxin-like PCBs.

Marine integrons containing novel integrase genes, attachment sites, attI, and associated gene cassettes in polluted sediments from Suez and Tokyo Bays

“…Xenobiotics are very often found in the context of the presence of industrial wastes such as dioxins and polychlorinated biphenyls, which commonly occur in Tokyo Bay sediments (Naito and Murata, 2007; Zushi et al , 2010). The location of TokyoGC16.1 as a first gene cassette may facilitate its high expression of the encoded esterase, as responses to toxic metals and antibiotics (Stepanauskas et al , 2005; Brandt et al , 2009).…”

“…It is exposed daily to high loads of petroleum wastes coming from the petroleum refining industry around the site, crude oil spills from the fixed oil pipes under the water and ships traveling through the Suez canal as well as other various anthropogenic wastes from the surrounding urban region (El-Agroudy et al , 2006; Nemr et al , 2006; this study) (Supplementary Table 1). The second site is located at the center of Tokyo Bay, 35° 26.71′ N, 139° 50.18′ E, where the sediment is contaminated with a mixture of industrial domestic wastes such as chlorinated polycyclic aromatic hydrocarbons such as dioxin and perfluorinated compounds (Naito and Murata, 2007; Uchimiya et al , 2007; Horii et al , 2009; Zushi et al , 2010) (Supplementary Table 1). The sediment samples were treated with 100 mM EDTA buffer and kept at −80° C for further analyses.…”

Effects on tree swallows exposed to dioxin‐like compounds associated with the Tittabawassee River and floodplain near Midland, Michigan, USA

“…Species at the top of the food web are generally considered to be the most likely to experience greater exposure to dioxin-like compounds [16][17][18][19][20][21][22][23]. However, higher trophic status species generally also have larger foraging ranges that can include offsite locations, potentially limiting site-specific exposures during the breeding season.…”

Ecological and Human Health Risk Assessment

“…Population-level assessments of the ecological risks of dioxin-like polychlorinated biphenyls exposure to fish-eating birds in Tokyo Bay and its vicinity were performed by Naito and Murata (2007) to judge the need for risk management measures to protect aquatic wildlife from dioxin-like polychlorinated biphenyls contamination.…”