The VIMS Shark Ecology Program, which has been tagging sharks on its longlining surveys since 1981, uses several types of tags—including dart, acoustic and satellite tags—to study shark movement and behavior.

I

Sharks are captured during the summer on the VIMS longline survey, which operates in the Chesapeake Bay and adjacent coastal waters. The majority of tagged animals are juvenile sandbar sharks, which are tagged with Hallprint nylon dart tags. These small dart tags are also used for smooth dogfish, Atlantic sharpnose sharks, and juveniles of other species. Hallprint M-type stainless steel dart tags are used for larger sharks, including adult sandbars, duskies, sandtigers and others.


   

The movements of juvenile sandbar sharks have been tracked in Virginia waters using acoustic tags. In Chesapeake Bay the sharks’ activities were followed by researchers tracking tagged sharks using a hydrophone. On the Eastern Shore, listening stations were set up in Wachapreague and Machipongo; these receivers recorded each time a shark with a sonic tag swam by.

In Prince William Sound, Alaska, acoustic tags were used to study the ability of salmon sharks to retain body heat. These sharks use counter-current heat exchangers (retia mirabilia) to keep their body temperature greater than that of the cold waters of their habitat. This allows them to hunt active prey like salmon.


   

Satellite tags have been put on large juvenile and adult sandbar sharks, as well as one very large sixgill shark. This is the first sixgill shark to be tagged with a satellite tag! Data from the tag showed the sixgill spent its days at depths of 300 m (approx. 980 ft) and its nights at depths of 200 m (approx. 650 ft).