Are Reef Sharks Dangerous Or Aggressive?

Caribbean reef shark

Written by Emmanuel Kingsley

Published: September 5, 2022

Share on:


Reef sharks are a category of sharks that typically inhabit coral reefs all over the world. There are five species of reef sharks. They are the blacktip reef shark, the whitetip reef shark, the gray reef shark, the Galapagos shark, and the Caribbean reef shark. They are right atop the food chain in coral reefs and would typically feed on crabs, shrimps, and other small reef fishes. 

As with most other sharks, reef sharks can be dangerous and aggressive, even towards humans. In this article, we will be seeing just how aggressive and dangerous they can be, with the help of facts and figures. 

Do Reef Sharks Bite?

Reef shark headbutts diver

Reef sharks have sickle-shaped teeth that help

©Konstantin Novikov/

The simple answer to this is reef sharks can bite and they can bite really hard. We wouldn’t expect anything less from a creature with species that can stretch up to 11 feet in length and boasts very scathy and sickle-shaped teeth. 

Like we mentioned earlier, adult reef sharks often rise all the way to the top of the coral reef food chain. They prey on everything from octopuses to reef crustaceans.

Reef sharks are not particularly aggressive towards humans but they can attack if they feel a great deal of threat. This means that attacks from reef sharks are typically provoked and very rarely unprovoked. Human divers around reefs are more susceptible to reef shark attacks. However, this rarely happens and even when they do bite humans, they do not bite to kill and eat.

Consequences of reef shark bites may include excessive bleeding because of their razor-sharp teeth and lacerations that can be medically sewn up. 

Are Reef Sharks Aggressive?

shark swimming near ocean floor

Although reef sharks are usually not aggressive, they can when they feel threatened.

©Richard Whitcombe/

Reef sharks are typically not aggressive but they can get aggressive in situations where they feel threatened. For example, the gray reef shark, which is one of the more aggressive species, only displays its aggression towards humans when it feels threatened and it could get very dangerous depending on the level of threat. 

Are Reef Sharks Dangerous?

A big reef shark swimming among a coral reef.

Reef sharks are not as aggressive towards humans as other sharks like bull sharks,


sharks, and great white sharks.


While reef sharks do not go out of their way to show aggression towards humans, prey including octopuses, reef crustaceans, and other such bony fishes would definitely consider them dangerous and harmful. 

Reef sharks have a physical appearance that is not particularly friendly even to humans. However, they are not nearly as aggressive towards humans as other sharks like bull sharks, tiger sharks, great white sharks, and the like. 

For one, reef sharks don’t attack humans unprovoked, and many times when they attack, it is likely because they feel threatened. That pretty much explains why since they started keeping records about a century ago, there have only been about 34 attacks on humans across all five reef shark species. While 34 might seem like a lot, we would like to mention that this is across millions of sharks and multiple thousands of human encounters. Even more interesting is the fact that only two of these attacks were fatal. 

When we consider these facts and put them in proper perspective, it becomes easier to agree with scientists who say reef sharks are just “moderately dangerous.” Also, we must add that it is not that reef sharks cannot kill humans. They possess jaws and teeth with the required sharpness, so they can actually kill humans but the figures show that they rarely do. The reason for this is simple- they do not consider humans food.

Are Reef Sharks As Dangerous As Great White Sharks?

The great white shark is often considered the most dangerous shark of all. They measure up to 20ft long and can weigh up to 4000 pounds, not to mention their incredibly ferocious jaws and teeth. So, it would be no surprise to learn that there have been 333 recorded attacks on humans from this species, with 52 of them being fatal. 

When you compare those numbers to the reef sharks’ 34 recorded attacks and 2 fatalities, the answer becomes obvious and incontestable. Reef sharks are not nearly as dangerous as great white sharks; not even close. 

How to Avoid Reef Shark Bites

Now, while we have established that reef sharks are not particularly dangerous and aggressive towards humans, that’s no reason to be carefree around them. 34 human attacks is not a lot when put in perspective but that’s still a number, right? The attacks are mostly non-fatal but having to deal with excessive bleeding and lacerations isn’t a joy ride. Hence, we have put together a list of precautions that can help avoid the unlikely event of a reef shark bite. Shall we?

  • Maintain calmness in the water

When swimming around reefs, divers and swimmers often want to dabble in erratic and rough movements to show their skills and just have fun. However, with such erratic movements come suspicions, a feeling of threat, and possible attack from reef sharks. So, as much as possible, divers should pump their brakes, even in water, and swim calmly. 

  • Stay Away From Them

It goes without saying that humans should not go near reef sharks of any kind especially when you don’t have any scientific business with them. Swimming too close to reef sharks may have them feeling threatened and they may react aggressively. 

  • Avoid Dusk and Dawn Swimming 

If you can, avoid swimming during dusk or dawn. That’s because reef sharks are lowlight predators and they are most active during dawn and dusk. You can reduce your chances of getting bitten by just not swimming during these times of the day. 

Up Next:

Share this post on:

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.