Annual Growth Increments in Shells of Spisula solidissima Record Marine Temperature Variability.

Systematic variations in annual growth increments, formed over a 16-year period in shells of the marine bivalve mollusc Spisula solidissima, reveal more growth in some years than others. Favorable years are indicated by larger than expected annual growth increments and successful recruitment of juveniles. Variations in the size of growth increments correlate negatively with sea surface temperatures. The results suggest that the annual growth increments in the shells of certain molluscs record changes in the marine environment and may be useful monitors of pollution and indicators of paleotemperatures.