There are hundreds of species of shark in the world. The most well-known are the largest, like the great white shark from the film Jaws. We know they attack humans, but humans also hunt sharks.
With this in mind, are sharks the top predators of the ocean?
Many shark species are apex predators. They have few to no natural predators and prey on others lower in their food chains. Sharks and other apex predators are an important part of a healthy ecosystem.
What Is An Apex Predator?
An apex predator is any animal that preys on others while the predator itself is not preyed upon. This often, but not always, puts them at the top of the food chain of their particular environment.
“Food chain” is a term that describes an arrangement of organisms (including plants and animals) of an environment in order of predation.
The highest members of a food chain eat the next organism down, while that organism eats the next lowest, and so on.
There are times when another animal may kill and/or eat an apex predator. This doesn’t have to change the apex hierarchy, though.
This occurs in intraguild predation when shared resources become scarce. It can also be as simple as humans hunting or killing apex predators in spite of other resources.
Many Sharks Are Apex Predators
There are over 500 different species of shark in the world. They can be as small as a human hand or grow to more than 39 feet (12 meters) in length. They have various environments, habits, and predatory natures.
Humans may hunt sharks, but since the predator/prey relationship isn’t naturally occurring for survival, sharks are still apex.
There is also a chance a shark could lose a fight with a predator that’s lower on the food chain but larger than the shark itself.
In spite of all this, many shark species are thought to be apex predators. Even peaceful filter-feeds like whale sharks are apex predators.
Even though they don’t eat any large animals, few, if any, larger animals prey on them.
The major exception to sharks at the top of the food chain is the orca whale and the great white shark.
While great white sharks are still major predators, they may not be the top apex predator. New evidence suggests that orcas, also known as killer whales, are natural predators of great white sharks.
Scientists note that when the two species cross paths, the great whites will leave the territory earlier than usual. Orcas will attack sharks and eat their livers, as seen in the video below.
Why Are Apex Predators Important?
To understand the role that apex predators play in their environments, it’s important to understand how ecosystems work.
Ecosystems And Biodiversity
An ecosystem is a complex network of relationships between interdependent organisms.
The entire planet is one giant ecosystem, but it’s also made up of smaller systems. The balance of the ecosystem is vital for clean air, water, soil, climate regulation, and food sources from plants to animals.
A key sign that an ecosystem is healthy is biodiversity. This means there’s a variety of organisms that have different functions.
The burden of maintaining balance in the ecosystem is spread out instead of concentrated on a few species.
Not only does this ensure that all of the ecosystem’s needs are met, but it reduces the risk of one event wiping out an entire system.
In short, the more variety of organisms in an ecosystem, the less likely that system is to fall apart.
Population Control From Apex Predators
Apex predators are important for an ecosystem because they provide crowd control.
The easiest prey tends to be the old and sick. By eating them, apex predators keep the rest of the prey population healthy and thriving.
At the same time, apex predators keep that population from growing too quickly.
An abundance of herbivores, for example, can lead to the diminishing of plant life. If there’s not enough plant life, there won’t be enough resources for other herbivore species.
This exact scenario occurred in Yellowstone National Park in the 1930s, and we’re still experiencing its effects to this day. The population of wolves, another apex predator, was killed off in the park.
While there were other predators still around, the missing wolves affected the elk population to a great extent. The elk thrived until they exceeded the capacity of Yellowstone’s resources.
This in turn affected the resources of other animals, such as the beaver.
What Do Sharks Eat?
If an apex predator’s main job is to eat to encourage diversity, what do sharks eat?
The great white shark, which is the world’s largest predatory fish, has a huge range of prey. Their preference is for large marine mammals such as sea lions and seals.
Another apex predator of the ocean is the tiger shark, which is also some of the largest sharks in the world.
These sharks will eat almost anything they can depending on where they live. They’ll eat anything from sea birds, dolphins, sea turtles, and even other sharks.
Along with great whites and bull sharks, tiger sharks are part of “the big three.” They are the most well-documented sharks to attack humans.
There’s even a top predator shark that eats seagrass in addition to smaller crustaceans: the bonnethead shark.
No one is sure why these otherwise carnivorous animals eat grass, but it makes up over 50% of their diet.
Bonnethead sharks also eat blue crabs. They are in fact their primary predator, aside from humans.
The blue crabs eat mud crabs, which eat even smaller invertebrates. So, the bonnethead shark is a top predator in its environment.
With such a large number of species in the world, sharks can have a wide range of predatory habits. But on the whole, experts do consider many sharks to be apex predators.
Sharks eat a wide variety of prey, which keeps their ecosystems in balance. Sharks can be frightening due to their enormous sizes and history of attacking humans. However, they are a necessary part of nature and are important to the world’s biodiversity.
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