Results Explained

This figure shows the vertical movement through the water column and associated water temperatures recorded from one sleeper shark, for several distinct periods.


For most of the shown period from late August through late November, this shark exhibited almost continuous movement from shallow depths of 30-60m, down to deepest depths of 250-300m. Often times vertical movement was stronger and ranged wider at night, but there were also periods when depth changes were much less accentuated. Generally, water temperatures occupied ranged from 6-7 C, with peaks above 10 C. 

Data recovered from a miniPAT deployed on a 2.4m immature female shark. Upper panel: Entire record from deployment through scheduled pop-up of PAT after 90 days. Blue trace = depth; purple trace = ambient water temperature. Lower left panel: 15 hour night-time data segment exhibiting regular and extensive vertical movement patters between approximately 20 and 200m depth. Lower right panel: 15 hour day-time data segment exhibiting regular but comparably reduced vertical movement patters between approximately 40 and 140m depth.