Shark Bait: Effects of hand-feeding on Fijian bull sharks

15916318558_1f4a071a00_oBull Shark” by Daniel Kwok is licensed under CC 2.0

When I was fourteen, my father bought me a handful of dried dog food from a dingy Bahamas beach store. With my fist closed tightly around the oily kibble and my goggles snug against my face, I dove into the warm Caribbean waters and watched as swirls of rainbow scales surrounded me. I opened my hand and the fish danced up, nipping at the food and my fingers. I was hit with awe after hand-feeding a few fish, but I’ve always wondered—how star-struck would I have been if I fed a shark as massive as the ones in those famous Hollywood block busters? If I, a small city girl, survived a face-to-face encounter with a 250-pound shark after it swiped a meal from my fingertips? Commercial tourism companies take advantage of emotions like these—of moments as addicting and beautiful as swimming with and feeding sharks—to increase their revenue. “As long as sharks remain alive in the ocean, divers and their dollars will continue to support local economies,” said Oceana Campaign director Sara Snyder in a recent report . Money aside, one fact remains—humans are now closer than ever to wildlife.

The growing attraction to wildlife tourism comes with its biggest question—how can hand-feeding affect the animals that consume these meals? A recent study published in Animal Conservation by J.M. Brunnschweiler and his colleagues aimed to find out more about the largely unknown effects of hand feeding on the energy requirements of the bull shark, Carcharhinus leucas, in Fiji. Despite the negative stigma that feeding wild animals tends to have, not all encounters are necessarily bad if carried out responsibly. It can even be beneficial—the study found that bull sharks occasionally meet their full energy requirement from hand-feeding at Fiji’s Shark Reef Marine Reserve.

Between January and March, the peak residency period for bull sharks at the Marine Reserve, Brunnschweiler observed 36 sampling dives as Fijian feeders hand-fed tuna heads to bull sharks out of a stationary bin. He individually studied the 10 adult bull sharks that arrived more than 10 times at the feeding site. These sharks were given rather fitting names—Hook, Whitenose, Bum, Granma, Flop, Grin, Chopper, Hotlips, Bumphead, and Scar. Over time, each individual shark’s feeding was observed, recorded, and analyzed.

Bull sharks are one of the largest sharks in the world, and on average, require about 1087 kilocalories per day. A single tuna head can fuel a bull shark’s energy requirements for 3.1 days, and the 10 bull sharks in Fiji consumed an average of 0.74 tuna heads per feeding day. Thus, the study concluded that bull sharks were fueling their energy requirements mainly from the feeding site at the Marine Reserve—in short, hand-feeding helped provide sustenance to these sharks.

Regardless of these findings, Brunnschweiler and his colleagues recognize that the 10 bull shark individuals they studied cannot fully represent the entire population of bull sharks that are being hand-fed. After all, the study only observed the bull sharks that arrived at the Marine Reserve the most often—other bull sharks, on the other hand, may not rely as heavily on hand-feeding for sustenance. Additionally, as with humans, each individual bull shark is unique in his energy expenditure and feeding habits. Nonetheless, this study reminds us of the increasingly significant role that wildlife tourism is playing in the lives of wildlife. While the full effects of hand-feeding bull sharks in Fiji is still unknown, we must recognize that studies such as these are useful in developing guidelines for sustainable wildlife tourism and its activities.

Despite the study’s focus on Fijian bull sharks and their ability to fuel energy requirements through hand-feeding, they are not the only marine animals feeding at these tourist sites. Food attracts all animals, and it’s important to recognize that this tourist attraction may apply to other marine life as well. As a child, I discovered the beauty in the intimate moments I spent face-to-face with the Caribbean fish. We must remember to approach such tourism activities with responsibility and respect, so that moments much like the one I experienced can be plentiful for the many more years to come.

 

References

Brunnschweiler, J. M., Payne, N. L., & Barnett, A. (2017). Hand feeding can periodically fuel a major portion of bull shark energy requirements at a provisioning site in Fiji. Animal Conservation. doi:10.1111/acv.12370. http://onlinelibrary.wiley.com/doi/10.1111/acv.12370/full

Oceana. (2017, March 21). New Report Finds Shark-Related Diving Generated Over $221 Million for Florida in 2016[Press release]. Retrieved October 24, 2017, from http://oceana.org/press-center/press-releases/new-report-finds-shark-related-diving-generated-over-221-million-florida

Link to photo: https://www.flickr.com/photos/danieldanielkwok/15916318558/

 

 

 

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This entry was posted in Conservation Biology Posts, Conservation News 2017. Bookmark the permalink.

One Response to Shark Bait: Effects of hand-feeding on Fijian bull sharks

  1. Pingback: Bulking up at Shark Reef! | Researching and Protecting Sharks

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