9531995 RADTKE An X-ray mapping, analytical microprobe technique will be tested to measure Sr/Ca ratios in the otoliths of larval cod fishes. Success with this procedure will identify the relationships between successive daily growth increments, vertical distribution/diel migration patterns, and hydrographic structure in the water column. Specimens collected from Georges Bank during the spring and early summer period when thermal stratification develops will provide information that should broaden an understanding of larval transport, survival and recruitment. ***