In 2006, when Sarasota Bay lost 2% of its dolphin population as a result of interactions with recreational fishing gear, dolphin depredation (taking bait or catch from anglers’ lines) became an even more pressing research concern for the Dolphin Research and Conservation Institute. Through a number of different methods including data mining, acoustic monitoring, focal animal behavioral follows, and surveys at fishing piers, this graduate research provided significant findings that are helping scientists and managers better understand recreational fishing depredation and manage dolphin behaviors associated with human interactions.
Since 2004 and 2005, there has been an increase in the number of incidents and number of dolphins engaging in human interaction behaviors within Sarasota Bay. Interactions between humans and dolphins include depredation, illegal feeding by humans (provisioning), begging, patrolling (dolphin “stalking” fishing pier or boat), and scavenging (dolphin feeding on anglers’ throwbacks). From 2000 to 2007, the month of March and the months following the end of a severe red tide bloom were found to have the greatest number of dolphin-human interactions. This is likely due to depletion of prey fish and increased numbers of anglers and boaters on the water. Dolphins that incorporated un-natural foraging habits (e.g., begging, scavenging, and patrolling) into their feeding strategies were found to shift away from natural activity patterns, suggesting that human interaction behaviors are not just opportunistic
but rather a more permanent change in activity patterns. In addition, adult male dolphins were more likely to engage in human interaction behaviors than were other sex or age classes. Most concerning was that nearly 60% of human interactions in 2007 and 2008 involved people illegally feeding wild dolphins. However, preliminary results suggest that targeted outreach and education can reduce illegal feeding. For example, illegal feeding of the notorious begging dolphin (Beggar) in Sarasota Bay was reduced by 30% after distribution of the “Dolphin Friendly Fishing and Viewing Tips” cards (see page 31 and 42-43).
Management of dolphin depredation is a concern for the Southeast Regional Office of NOAA Fisheries because of the broad management concerns and the proliferation of these behaviors. Depredation has now been reported along the coasts of Florida, Georgia, South Carolina, North Carolina, Texas, and Alabama (see map). We, at the agency, rely heavily on current research to identify management priorities and assess the effectiveness of current strategies. The research from Sarasota Bay is currently the only literature available about dolphin interactions with recreational fishing gear. With guidance from this research, we are utilizing a number of different methods to help reduce serious injuries and mortalities to dolphins as a result of interactions with recreational fishing gear as well as to educate people about the harms of interacting with wild dolphins. A tool which has been invaluable for education is the Don’t Feed Wild Dolphins public service announcement created in part by the Chicago Zoological Society and NOAA Fisheries. We are also planning to expand Dolphin SMART, a voluntary recognition and educational program for commercial wild dolphin viewing tours that follow program criteria and educate their customers about the importance of responsible viewing and conservation of wild dolphins. In summary, partnerships between NOAA Fisheries and researchers, such as DRCI, are essential to mitigate the various management challenges associated with dolphin-human interactions.
Graduate research was supported by the Disney Wildlife Conservation Fund, Fish Florida, and an assistantship from the University of South Florida, College of Marine Science.