Biological effects of contaminants
A range of techniques are used to determine the effects of contaminants in biota. The organotin tributyltin (TBT) is monitored by assessing imposex in dog whelks. Measurement of a detoxification enzyme (EROD (7-ethoxyresorfin-O-deethylase) activity) in fish indicates exposure to organic compounds including PCBs. PAH bile metabolites (included in the PAH hazardous substance assessment) can also be measured in fish. The assessment of external fish disease can be used as a general health indicator of the fish population. The Case study: Imposex in Sullom Voe reports on long-term monitoring in the voe.