"Modeling the population-level ecological risks of dioxinlike PCBs on fish-eating birds from Tokyo Bay" 

Wataru Naito

National Institute of Advanced Industrial Science and Technology

SETAC North America 26th Annual Meeting (Baltimore, USA  2005/11/15)

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Abstract

Population-level ecological risk assessments of dioxinlike PCBs on fish-eating birds was performed to judge the need for risk management measures to protect aquatic wildlife from dioxinlike PCBs contamination in Japan. Egg mortality risk and the changes in population growth rate, , in relation to the contamination levels of dioxinlike PCBs in eggs of four different types of fish-eating birds were determined by integrating the results from both bioaccumulation and life-history models. Assuming dioxinlike PCBs contamination levels observed in the Tokyo Bay and its vicinity, egg mortality risks for grey heron, great cormorant, osprey and kingfisher populations were 5.8, 6.8, 12 and 1 %, respectively. The estimated for grey heron, great cormorant, osprey and kingfisher populations were all greater than one, in case of the current dioxinlike PCBs contamination levels observed in the Tokyo Bay and its vicinity. Judging from the results of the analyses, current contamination levels of dioxinlike PCBs observed in the Tokyo Bay and its vicinity pose little risk on the fish-eating bird populations, thus, along with a decreasing trend of dioxin and dioxinlike PCBs levels in the Tokyo Bay, there is at present no need for urgent risk reduction measures for protecting fish-eating bird populations for dioxinlike PCBs. 

Keywords

integrated approach, ecological risk, population level effects, dioxinlike PCBs