Are Bull Sharks Really Aggressive Toward Humans?
The bull shark is a widely known species of Carcarhiniform, typically mentioned for their “aggressive” behavior and attacks on humans. The question is: are these sharks really hunting humans? And if they are, why is shark feeding and tourism so popular for this species?
Personal Experiences Diving with Bull Sharks
My name is Kendall Traiser, and I am a PADI Dive Master and an avid shark diver. I scuba dive with sharks like bulls, lemons, duskys, silkys, hammerheads, tigers, etc., and yes, we do feed these animals while interacting with them underwater. I would like to note that bull sharks in particular have not shown any super aggressive behavior when I have been underwater with them. However, they are very capable of taking a limb off, so please remember these are wild animals, and everyone running hese dives is extremely experienced.
Understanding Bull Sharks: Nature vs. Stereotype
Bull sharks have a typical “shark” nature and behavior. They are stocky, large sharks with an intimidating appearance, with strong jaws and beady black eyes. At first glance, they do look frightening, but there are a lot of stereotypes associated with the bull shark that, in my opinion, are just not fair. The bull shark is a very curious shark, and that’s all there is to it. They don’t fear humans the way other species do; they want to figure us out. This leads to high interaction possibilities. They come in and bump the divers with their noses, see what happens when they charge us or treat us like their prey, and generally just see what we’re up to. Because of their curiosity, they also have a high attack rate. I do not believe they ever want to hurt humans. More often than not, it is an accident.
Bull Shark Bite Data and Human Interactions
A study conducted by J. Tucker et. al. observed the survivability of shark bites, finding that out of 157 bull shark bites over a 30-year time frame, 60 were fatal. However, this study analyzed statistics spanning from 1791 to 2022, and it was noted that “the probability of surviving an unprovoked bull shark bite has increased over years (Tucker et. al 2022).” This is likely due to an increase in healthcare standards and a rapid response time to shark bite reports. It is also possible that, since bull sharks are more likely to be found in brackish or near-shore waters, it is easier for someone who has been attacked to get to shore for aid.
My theory, though, is that these sharks’ minds are evolving. They are learning to take smaller test bites, sniff around before biting, and spit out human flesh when they recognize it. Of course, this is not a tested theory, but in my 10 years of experience around these sharks I have definitely noticed their behaviors become more careful and cautious. This could be due to the sharks watching as others of their species get overfished and killed for their curiosity.
The Controversy Around Feeding Sharks
There is a controversy about feeding sharks. Many people believe that humans giving food to sharks can make them more aggressive, overly comfortable around humans, or even change their hunting behavior and migration patterns, impacting their survival. While this is a valid assumption, it has been proved to be inaccurate.
Do Shark Feeding Operations Impact Shark Behavior?
Brena et. al. (2018) conducted a meta-analysis reviewing 22 studies that examined the effects of provisioning sharks and rays, along with their behavioral, ecological, and physiological responses to feeding elasmobranchs for tourism purposes. Upon observation, researchers found that “no correlation has been demonstrated so far between provisioning operations and unprovoked shark and ray bites (Brena et. al. 2015).”
However, the same analysis presents a study that offers insight into “provoked” or otherwise enticed attacks. In 54 cases of shark bites in a 22-year span, 25 cases (45%) were linked to shark provisioning operations (Maillaud & Van Grevelyngh 2005). Please note that these attacks were due to factors like fish blood or flesh being near the person attacked, and in many instances the feeders themselves were the ones bitten.
It has also been observed that the general abundance of sharks in areas where shark feeding occurs does increase over time. Brunnschweiler & Baensch (2011) found a sixfold increase in the bull shark population in Fiji over seven years and claimed that this increase is indeed linked to these feeding operations.
However, the presence of sharks in an area does not mean their behavior toward humans is any more aggressive than it was in the past. It simply means that the sharks have learned where to expect snacks. Lastly, Brena et al. state, “The observed seasonality in the abundance of sharks at several provisioning sites indicates that individuals maintain their natural migrations and that provisioning activities are unlikely to permanently alter them (Brena et. al. 2015).” This is a crucial finding, given that this study reviewed years worth of research to come to the conclusion that shark behavior is generally unaffected by shark feeding operations.
Observations of Bull Sharks in Feeding vs. Natural Environments
I have personally witnessed these sharks both in a feeding area, such as Jupiter, FL, and in their natural environments: Belize, Cayman Islands, Turks and Caicos, Bahamas, etc. I have not observed a significant difference in their behaviors in each situation. Bull sharks are always curious and always come in close. When feeding, they come in a bit closer to the divers than they do naturally, but that is to be expected.
How Bull Sharks Respond to Boats and Human Activity
I would also like to note that we have methods of identifying sharks that we have known for a while (mating scars, noticeable markings, etc.), and these sharks do still migrate when expected. According to Simpfendorfer and Burgess (2009), “in the western Atlantic, bull sharks migrate north along the coast of the US during summer, swimming as far north as Massachusetts, and then return to tropical climates when the coastal waters cool.” We have realized a notable decrease in bull shark presence when the water is warm, which is consistent with other large shark species.
The only change in shark behavior that I have ever noticed is that these sharks have begun coming up to the boat when they hear the whirring of the engines. This could mean that sharks have started to associate the sound of a boat engine with food, which may pose concern for their association with humans. They may be becoming slightly too close for comfort for some people.
Why Empathy and Protection for Bull Sharks Matters
Personally, I stress the importance of empathy for creatures larger and more powerful than ourselves. The immediate response to these animals is fear, and when humans fear something, they eliminate it. But before jumping to that, ask yourself: what would happen if we treated these apex predators as equals?
Sharks are a vital component of our ocean ecosystems, and without them, the food chain as we know it risks collapse. By extension, the ocean as a whole is at risk. Protecting sharks is protecting the ocean, and it needs to be prioritized.
##
Interested in meeting a bull shark? Bid on the Shark Angels auction item generously donated by Beqa Lagoon Resort this year! Sign up to be notified when auction starts.
Shark Angels are strong supporters of ethical shark diving. Here’s why…
Written by Kendall Traiser, PADI Dive Master, Shark Diver, and Shark Angels Intern
SOURCES:
Tucker, J., et al. (2022)
Study: Survivability and Fatality Patterns in Bull Shark Bites: A Historical Analysis from 1791–2022
Brena, P.F., Mourier, J., & Planes, S. (2015)
Study: Shark and ray provisioning: Functional insights and management implications from a global meta-analysis
Maillaud, C., & Van Grevelynghe, G. (2005)
Study: Shark attacks and feeding tourism in New Caledonia: A medical and ecological review
Brunnschweiler, J.M., & Baensch, H. (2011)
Study: Seasonality, Aggregation and Movement Patterns of Bull Sharks (Carcharhinus leucas) at the Shark Reef Marine Reserve, Fiji
Simpfendorfer, C.A., & Burgess, G.H. (2009)
Study: An overview of the ecology and status of bull sharks (Carcharhinus leucas) in the western Atlantic Ocean