Anecdotal reports from blue crab fishermen in the Indian River Lagoon
(IRL), Florida suggested that bottlenose dolphins (TursiopJ truncutus) followed
their boats, and stole bait fish from crab pots soon after they were deployed. To
investigate these reports, we made biweekly observations from IRL commercial
crab boats from January 1998 to January 1999 (670 h). Only 2.8% of the
18,891 crab pots surveyed revealed evidence of dolphidcrab pot interaction.
Dolphin interactions included: (1) begging at boats, (2) feeding on discarded
bait fish, (3) engaging in crab pot tipping behavior, and (4) dolphin mortality
from crab pot float line entanglement. Overall, 16.6% of the 1,296 dolphins
sighted interacted with fishing boats. Seasonal trends were evident, with fishery
interactions peaking in the summer. Crab pot interactions ranged from 0% to
36% of the traps checked daily. Different methods of securing the bait-well
door and the role of trap locality were tested using a replicated experimental
design. Results showed significant differences in successful bait removal by dolphins,
among the degrees of door security (P < 0.001) and between trap location
(P < 0.01). Thus, increased door security may help to reduce the negative
impacts to the fishery and dolphins involved.