Evaluation of bone strontium as a measure of seafood consumption

The recognition that bone strontium/calcium ratios reflect dietary levels of strontium and that seawater has a high strontium content led some archaeologists to infer that seafood consumption produces high Sr/Ca ratios in bone. Analyses of seawater and of marine organisms reveal, however, a marine trophic effect comparable to the trophic effect seen in terrestrial food chains. This marine trophic effect reduces the Sr/Ca levels in seafood such that marine dietary resources have Sr/Ca levels comparable to those of terrestrial resources. Thus, bone Sr/Ca ratios can not differentiate consumption of marine and terrestrial resources. Also, Sr/Ca of bones from archaeological sites where seafood was an important component of diet were found to be within the range of entirely terrestrial diets. Copyright © 1999 John Wiley & Sons, Ltd.