Assessment of heavy metals in tropical rock oysters (blacklip and milky) and implications for placement into the Australian seafood market and for Indigenous enterprise development in the NT

Results were used to determine whether heavy metal levels exceeded the Maximum Residue Levels (MRLs - or MLs as the more commonly used terminology) set by Food Standards Australia New Zealand (FSANZ) within the Australia New Zealand Food Standards Code (ANZFSC). The range of metals tested were chosen based on previous national residue surveys in seafood across the NT (and our preliminary screening of the study site) that indicated likely contaminants. For example, in this study mercury was not tested as the preliminary screening test done on South Goulburn Island indicated mercury to be low (0.005-0.007 mg/kg; ML 0.5mg/kg) and previous extensive heavy metal testing done by various national surveys along the NT coastline over the last few decades reported consistently low levels of mercury in various seafood products.