The behavior of 14 ringed seals (Phoca hispida) diving under shore-fast sea ice was monitored acoustically during the spring breeding season. Frequent dives with extended periods at depth by subadult and adult seals, including lactating females, were interpreted to be foraging dives. Median dive durations were less than 10.0 rain for all seals, and the maximal observed duration was 26.4 min. The maximal observed dive depth, 222 m, was limited by water depth in the study area. Modal dive depths were between 10 and 45 m for breeding-age males and between 100 and 145 m for subadult males and postparturient females. Median dive durations were 4.0 min for adult males and 7.5 rain for adult females. Body mass was a better predictor of maximal dive duration (r2 = 0.94) than was age, but maximal durations were shorter than were predicted using measures of oxygen stores and presumed metabolic rates. There was no consistent relationship between light level and the frequency or depth of dives.
