Cadmium And Mercury Dr. David Clark asked the Secretary of State for Scotland what research has been undertaken in Scotland into levels of cadmium and mercury in the flesh of grouse or other game and in the flesh of trout and pike; and what were the results of that analysis. Mr. John MacKay There is currently no programme being undertaken on heavy metals by my Department either for fish or for grouse or other game. A survey of heavy metals in fish flesh, including cadmium and mercury, was however conducted by my Department's freshwater fisheries laboratory in 1977. The values for cadmium in trout and pike were less than 0·04 micrograms per kilogram. The value of mercury in trout ranged from 0·15 to 0·06 micrograms per kilogram and in pike from 0·9 to 0·2 micrograms per kilogram. There is no reason to believe that these levels have increased significantly.