Weighing a seal

Dear Friend,

Tagging a seal is easy compared to weighing one. A big adult can weigh more than 1,000 pounds—almost as much as a small car! To weigh a seal, scientists usually put it in a sling, which is then attached to a scale. Doing this is difficult and time-consuming. The scientists shown here are trying a new, easier way of learning a seal’s weight. They photograph the top and front of the seal, then compare it to other seals whose weight is already known. (In this photo, one pole is just a big ruler, and the other pole holds the camera.) If the new way works, scientists won’t ever have to weigh seals again!

Marine mammals enjoy special protection in the United States. Research on marine mammals (including photography) within U.S. jurisdictions or when based at a U.S. institution requires a permit under the U.S. Marine Mammal Protection Act. Bob Marstall, who took this photo, is listed on Robert Garrott’s permit, which is Marine Mammal Permit #1032-1679-00.

Your friend,

Bob