FIGURE 2.

Cumulative time spent at depth in Scoresby Sound, presented as percentages for one narwhal instrumented with a SLTDR (left) with an exceptionally long record (#3963, 83 ds) and the mean of 16 narwhals instrumented with Acousondes (middle, 4–8 ds). Time spent at 0–10 m (not shown) was 44% for #3963 and 47% (SD = 9.62) for the Acousonde data. One SD is shown for the mean of the Acousonde data. Note the increased attendance to depths between 300 and 500 m. The right figure shows the percentages of the target depths (maximum depth reached during 915 dives) for one whale instrumented with a SMRU transmitter. For this, whale about 43% of the dives targeted depths < 10 m