The principal investigators are continuing their research on the use of Sr/Ca ratios in fish otoliths to resolve questions about an organism's growth rate history and about the environmental conditions that fish were exposed to during their growth. There are two phases: (1) a laboratory phase to improve the technique the investigators developed to examine Sr/Ca ratios in otolith bands, and (2) a field phase to gain insight into how the overwintering distibutions of herring larvae in the Gulf of Maine may affect recruitment. For the field component of their study, they will determine the distribution of herring larve shortly after spawing in the fall and in mid-winter. The data obtained will be compared with Sr/Ca otolith measurements on adult fish to determine if the distribution of larvae observed is reflected in the otolith banding.