Sharks are one of the most feared and fascinating creatures in the ocean. With their powerful jaws and razor-sharp teeth, they have dominated the ocean’s food chain for millions of years.
However, they’re not always as big as we think them to be! There are over 500 species of sharks, ranging in size from the tiny lantern shark, which can fit in your hand, to the massive whale shark, which can reach lengths of up to 60 feet.
And despite their reputation as the apex predator, sharks have natural predators and face human-induced threats that can impact their populations. So, if the question “what eats sharks?” is eating you from the inside (pun intended!), keep reading to find out everything about shark predators.
What Animal Eats Sharks?
You won’t find many animals or creatures that can eat a shark! Here is a list of some formidable competitor that has shown mastery in consuming them:
1. Orca / Killer Whale
The orca, or killer whale, is the ocean’s most formidable predator, and this is due to its unbelievable intelligence. Orcas coordinate attacks in pods, like wolves. They capture and then attack their prey.
A group of researchers from the Monterey Bay Aquarium observed that great white sharks would leave an area of the ocean if they detected the presence of killer whales, and they often would not return for several months. They compared data from 2006 to 2013 and found that there were 62% fewer seals being eaten by sharks during the years when orcas were present.
This evidence suggests that the presence of killer whales forces great white sharks to seek out different hunting grounds.
Orcas seem to have a particular interest in the shark liver, which is rich in calories and has been known to leave shark carcasses with the liver missing, revealing orca teeth marks. This intense hunting method may explain why great white sharks prefer to stay away from areas with orcas.
2. Sperm Whale
The sperm whale is a massive creature, growing up to over 67 feet (20.5 meters) in length and weighing up to 90 tons (81 metric tons). It is the largest tooth-to-whale and also the largest known active predator on earth.
The sperm whale commonly dives to great depths to hunt for giant squid, fish, and even sharks. From 1990-1996, a study looked at whaling records to find out what sperm whales eat. The researchers found several large (1-3 m) sharks in the whales’ stomachs.
They are found worldwide in both tropical and polar waters and have been found with basking sharks, megamouth sharks, and mako sharks’ remaining in their stomachs.
3. Fur Seals
While it’s true that seals are commonly the prey of great whites, it doesn’t mean that they can’t be predators themselves. For example, in 2012, fur seals near Cape Town, Africa, were observed killing sharks at a tourist attraction.
Chris Fallows, a shark expert, observed ten blue sharks while he was inside a shark cage, but suddenly, a fur seal made its appearance and ate five of the sharks.
The seal only ate the viscera, which was the most high-energy part of the shark, but it’s still interesting to note that what is usually prey becomes the predator.
4. Goliath Grouper
The goliath grouper grows to enormous proportions, weighing more than 800 pounds and measuring more than 8 feet in length. These massive fish are predatory and eat just about anything, including octopus, fish, and yes, even sharks. In 2018, some fishermen off the coast of Everglades City, Florida, witnessed a giant goliath grouper eat a 3-foot shark.
They are considered garbage disposals of the sea; they eat everything in sight; and they are protected in many countries due to their declining populations.
5. Swordfish
Swordfish have been recorded attacking sharks since the early 1960s. Studies have found that swordfish are killing sharks on a regular basis, with blue and mako sharks being the most common victims.
Additionally, there is evidence of seafood fraud in the Mediterranean, where consumers may be unknowingly eating sharks instead of swordfish. Therefore, it appears that swordfish do eat sharks.
6. Giant Pacific Octopus
The giant pacific octopus is the largest known species of octopus alive today and can reach a maximum size of 30 feet and over 500 pounds.
These octopuses mainly eat crustaceans and clams but have been known to eat small sharks as well, using their sharp beaks. For example, there is a video of an octopus at an aquarium consuming a spiny dogfish shark.
Do Big Sharks Eat Little Sharks?
Yes, big sharks do eat little sharks. Large predatory sharks such as great whites, hammerheads, tiger sharks, and bull sharks are known to practice cannibalism and have been observed eating smaller species of shark.
This behavior is known as adelphophagy, which literally means “eating one’s brother.” You might have learned about the food chain in school, where bigger fish eat smaller fish. It’s kind of like that for sharks, but it also depends on what kind of food is available.
In addition to cannibalism, some species of shark also practice embryonic cannibalism, where larger embryos consume smaller ones in the womb. Sand tiger sharks have been seen doing this. In a Seoul aquarium, a female 2.2m (7.2ft) long slowly ate a male 1.2m (3.9ft) long banded hound shark.
Are Sharks Afraid of Dolphins?
Sharks are generally afraid of dolphins due to their physical characteristics (they can easily outmaneuver sharks in one-on-one fights), intelligence, and ability to live in pods.
Sharks have a taste for baby dolphins; that’s why mother dolphins will protect their young from shark attacks by forming protective circles around them. Dolphins are also known to behave aggressively toward sharks, so if a shark senses danger, it will likely flee.
Human-Induced Threats to Sharks
Now that you know what eats sharks, you may be wondering whether humans have any hand in the decreasing shark population. Believe it or not, sharks are threatened by humans more than any other animals! According to research, humans are responsible for killing an average of 100 million sharks annually.
The main human-induced threats to sharks are:
- overfishing,
- finning,
- fisheries bycatch,
- habitat and prey loss, and
- human disturbance.
1. Overfishing
Overfishing is the biggest threat to sharks globally, and many tens of millions of sharks are landed each year due to the high demand for shark products. This can lead to declines in shark populations, as well as disruptions to the delicate balance of the marine ecosystem.
2. Bycatch
Sharks are often unintentionally caught while fishing for other species. In fact, tens of millions of sharks are caught as bycatch each year, with global bycatch amounting to 40% of the world’s catch, totaling 63 billion pounds per year.
This is a huge problem, as many shark species have slow reproductive rates, making it difficult for their populations to recover from such heavy fishing pressure.
3. Finning
Finning, the practice of removing a shark’s fins and discarding the rest of the body, is a major threat to shark populations. Estimates suggest that approximately 100 million sharks are killed annually worldwide for their fins.
This is often done to supply the demand for shark fin soup, a traditional delicacy in some cultures. This is called a “massacre for soup” by the Shark Research Institute.
4. Pollution
The ocean is full of plastic and other toxic substances that can harm or even kill these magnificent creatures. They can become entangled in commercial shipping nets or ingest plastics and their toxins.
Filter-feeding sharks and mobula rays are especially vulnerable to microplastic pollution, while climate change and an increasingly polluted ocean also have an adverse impact on sharks.
Role of Sharks in the Ecosystem
Sharks play an important role in the ecosystem by maintaining the species below them in the food chain and serving as an indicator of ocean health. They help remove the weak and the sick, as well as keep the balance with competitors to ensure species diversity.
Sharks are at the top of their food chains, which means they don’t have many natural enemies. As the apex predators in the food chain, sharks eat animals below them. This helps keep the sea ecosystem healthy.
Research in Shark Bay has revealed that sharks play an important role in maintaining a balanced ecosystem, not just as predators but also as regulators. By controlling the population of other species, they prevent them from becoming too abundant or scarce.
This helps to ensure that there is enough food for all species and that no one species becomes dominant. Sharks also provide essential nutrients to other organisms in their environment through their waste products.
Related Article: Are Sea Lions Dangerous to Humans
FAQs
1. Can a Shark Eat a Whale?
Yes, certain shark species, such as the great white shark, are capable of eating small whale species, such as calves, but adult whales are too large for a single shark to consume.
2. Has a Shark Ever Saved a Human?
There have been several instances of sharks saving humans. In 2015, Eugene Finney was swimming off the coast of California when a shark attack revealed he had cancer. A great white shark saved a South African from four tiger sharks in 2020.
3. Do Crocodiles Eat Sharks?
Saltwater crocodiles are the only species of crocodile able to regularly hunt and consume sharks. They attack sharks in shallow waters in their territory. However, this type of predation is relatively rare.
Conclusion
Sharks may be one of the top predators in the ocean, but they are not immune to threats from both what can eat a shark in nature and human-induced factors.
When it comes to what eats sharks, it’s important to understand the role these creatures play in the marine ecosystem and the various threats they face to properly conserve and protect them. Let’s work together to protect these magnificent creatures and the delicate balance of the underwater world.
