Sharks and the buddy system

In addition to the electropositive metal study we also deployed four pop-up satellite tags in western Greenland near Qeqertarsuaq (Disko Island, ~69º13 N, 53º.36 W) to study the Greenland shark’s short term movements. The tags reported in late 2011. Over the course of 3.5 months, all four of the animals had travelled to a location approximately 800-1000 km north (76º N, 69.5º W) of their release site. Interestingly, two of the sharks were within 1.5 km of each other when the tags detached, floated to the surface and began sending location data to the satellite orbiting overhead. Data subsequently downloaded from the tags indicates that during most of their travels the sharks tended to swim at a depth of 250-350 m where the water temperature was 2.5-3 C. There were some occasions, however, when they went as deep 1600 meters where water temperature was -1 C. Only one of the four ever came within 50 meters of the surface. We are currently analyzing the massive amounts of data we were able to retrieve in order to get a better sense of their daily swimming patterns and how they might be using the water column.