Teams of conservation scientists looking at the impact of tourism on tiger sharks have, for the first time observed them in social groups near an area called Tiger Beach off the north-west side of Little Bahama bank in the Bahamas, a popular spot for tourists.
Published today (Friday, 3 September) in Frontiers in Marine Science, the study, led by ZSL’s Institute of Zoology, Lancaster University and the University of Miami Rosenstiel School of Marine and Atmospheric Science (UM), reveals that tiger sharks appear to choose and form social groups a contrast to previous understanding but that their social preferences for each other tend to break down when they are exposed to bait provided by shark diving experiences, at Tiger Beach.
Many dive tourism businesses around the world use baited shark dives to draw the creatures so that visitors can see them. Some conservationists and shark experts, due to the possible long-term impacts on the predators, including changes to their natural hunting behavior, have criticized this approach.
This study is the first of its kind to examine how tiger shark social behavior is impacted by bait feeding. The sharks did display a “take it or leave it” attitude toward the bait feeding, suggesting that the consequences on their social behaviors are not long-lasting, despite the study’s findings that interactions between the sharks appear to become more random when food is offered.
According to the study, sharks might probably preserve their natural habits when without being fed and avoid reliance if the frequency of tourism activities doesn’t increase.
Given that tiger sharks spend months at a time out in the open ocean as solitary predators, it’s amazing to me that they show social preferences when they aggregate in the Tiger Beach area.
Dr. Neil Hammerschlag
Dr. David Jacoby, ZSL Honorary Research Associate, now at Lancaster University and lead author of the study said:
“The boundary between wildlife and people is becoming increasingly thin, so as well as observing a new social behavior for the first time in what was once thought of as a solitary shark, we also measured the impacts of human activity on these predators’ interactions. Luckily, they seem to show some resilience to the bait feeding.”
The tiger sharks were observed using a mixture of acoustic tracking data as well as social network analysis of behavior over three years.
Researchers working on the study included scientists from the University of Miami Rosenstiel School, Carleton University in Ottawa Canada, Florida International University, Beneath the Waves Inc, the South Carolina Department of Natural Resources, and Lancaster University. The area of Tiger Beach that was investigated is known to host a high density of female tiger sharks, especially during winter months, about a quarter of which are pregnant.
“Given that tiger sharks spend months at a time out in the open ocean as solitary predators, it’s amazing to me that they show social preferences when they aggregate in the Tiger Beach area,” said Dr. Neil Hammerschlag, senior author of the study and research associate professor at the UM Rosenstiel School. “For nearly two decades, I have spent countless hours diving at Tiger Beach always wondering if these apex predators interacted socially. Now we know.”
The social behavior of predators is an important area of study as it provides another tool to help conservationists build a picture of how they live, what drives them to form social groups, and the roles they play within the wider ecosystem.
Dr. Jacoby concluded: “We hope that if the frequency of these dive trips doesn’t increase, the sharks may be able to retain their natural behaviors regardless of their time spent near tourists during dives.”
