Strontium and barium in otoliths are mainly from ambient water where fish survives. These two elements precipitate into otoliths crystal lattice or interstitial to substitute for calcium (Ca2+) in vaterite or aragonite. The precipitation of otoliths is controlled not only by biological regulatory, but also influenced by environmental factors, such as: element concentration, salinity, temperature of ambient water, food intake, etc. So there is a response relationship between element partition coefficient and ambient environment. The element concentration of ambient waters is the most significant one among all above mentioned environmental factors. In general, the element concentration in the otoliths is positively correlated to those in the ambient waters. When multielements coexist in the ambient waters, there exist synergism and antagonism between some ions, for example, synergism between strontium and barium, and antagonism between calcium and strontium or zinc. There is no simple correlation between element partition coefficient and salinity or temperature; for some certain species and specific range of values, there exist some good correlations. Based on the specificspecies situation and selecting those elements that are affected greatly by environmental factors than by biological regulatory, such as Sr, Zn, Pb, Mn, Ba, Fe, Li, Ni, Cd, etc., we could use the response relationship to monitor the ecological environment and to manage fishery.
