Journal of The School of Marine Science and Technology,Vol.2 No.2
Bioaccumulation of PCBs and DDE in cloudy catshark,
Scyliorhinus torazame,caught in four locations around Japan
Taku HORIE,Hiroyuki TANAKA and Sho TANAKA
Abstract
Only a few biology-and ecology-based studies have been conducted on the bioaccumulation of polychlorinated biphenyls(PCBs)and dichlorodiphenyl dichloroethylene(DDE)in sharks,which are the top predatory fish.We analyzed the concentrations of PCBs and DDE in the cloudy catshark,Scyliorhinus torazame,caught in four locations around Japan.A total of 30 sharks were caught from Aomori Prefecture(8),Fukushima Prefecture(8),Ibaraki Prefecture(7),and Tsushima Island(7),The ranges of concentrations of PCBs on a lipid weight basis in the four locations were 0.40-1.5μg/g,0.41-1.6μg/g,0.69-2.4μg/g,and 0.54-4.4μg/g,respectively,and those of DDE were 0.077 -0.82μg/g,0.17-0.63μg/g,0.25-0.78μg/g,and 0.48-1.6μg/g,respectively.Among the sharks caught from Tsushima Island,the concentration of both chemicals was higher in mature males than in mature females.During ovulation,the PCBs and DDE may be transferred into the eggs of the mature female.The ratio of DDE to PCBs in the sharks from Tsushima Island was significantly higher than the ratios obtained in other locations.This result suggests the recent use of DDT by developing Asian countries located to the south of Japan.The ratio of trichlorinated biphenyls to total PCBs in Aomori Prefecture was higher than the ratios obtained in other locations.The difference in PCB composition in sharks from Aomori Prefecture could be attributed to the Kurile Current.The main PCB isomers detected in cloudy catsharks were IUPAC Nos.153,138,118,180,and 187,The influence of toxicity caused by the coplanar PCB (IUPAC No.118)in the cloudy catshark is a matter of concern.