Total DDT was recorded in a high percentage of the biota tissues analysed during the Study. Significantly higher Total DDT levels in biota were recorded from the Deep Bay station (P < 0.05). The lowest values for DDT were reported from biota collected in Port Shelter and Mirs Bay. Statistical analyses of the data revealed that the highest levels of Total DDT were recorded in August 1999 in some of the biota (ie Metapenaeopsis barbata, Oratosquilla interrupta and Charybdis affinis).

There was a clear trend of increasing Total DDT concentrations from east to west. This trend would suggest that the major source of Total DDT in biota from Hong Kong marine waters is located in the west. It is possible that this may be due to elevated inputs into local waters from the Pearl River. It is known that DDT is accumulated by marine biota to higher levels from water of lower salinity(78) such as in river estuaries. As a consequence of this the higher values recorded in the west may be more a reflection of higher accumulation rates than elevated inputs.

TBT was rarely detected above detection limits in biota tissues analysed. This result concurs with data obtained for TBT in sediments. The analytical procedures used in this Study were some of the most advanced available both internationally and in Hong Kong. No statistical analyses was conducted on TBT tissue data owing to the small number of data points recorded above the detection limits.