STUDIES OF THE EFFECTS OF NET FRAGMENT ENTANGLEMENT ON NORTHERN FUR SEALS PART 2: SWIMMING BEHAVIOR OF ENTANGLED AND NONENTANCLED FUR SEALS

The effects of net fragment entanglement on the swimming behavior of fur seals were observed. Net fragments of six different weights (0.5 to 3 kg) were attached to the necks of eight fur seals, two males and six females, 4 to 9 years old. They were released in an aquarium pool with fish, and their swimming speed and time required to capture a fish were recorded. Of the eight individuals examined, three showed active feeding behavior. As the amount of attached net was increased, swimming speed decreased and more time was required for an entangled seal to catch a fish. Decrease in swimming speed was proportional to the relative load of net fragments (net weight/body weight).