Factors controlling lead availability to the deposit-feeding bivalve Macoma balthica in sulphide-rich oxic sediments

Tissue lead levels in the deposit-feeding bivalve Macoma balthica have been compared with the physicochemical components of oxic sediments near an ore concentrate stockpile and loading facility. The results indicate that weak acids such as 1N HCl extract a significant portion of the lead from the sulphide fraction and may overestimate its bioavailability in sulphide-rich sediments. Normalizing the extracted lead levels with the total sulphur content in the sediments significantly improved the predictability of lead uptake in the bivalves.