Maintaining shark populations thriving is necessary to have healthy oceans that provide us everything we need to survive – from the oxygen we breathe to the food we eat. But people tend to think of sharks as large, dangerous monsters, circling every coastline ready to wage war on humans. Negative media talk of “shark-infested” waters, as if the sea is our home, rather than theirs and “beasts lurking beneath the waters” continues to stoke the needless fear humans have about sharks.
The truth is, sharks are the most maligned and misunderstood creatures on the planet. Sharks are apex predators, at the top of the food chain and are vital to a healthy ocean ecosystem. Without sharks, ocean life as we know it would not exist.
Here are 4 reasons why sharks are crucial for ocean ecosystem health:
1. Sharks keep prey populations healthy
Sharks don’t just live in the ocean, they shape the ocean and have done so for over 450 million years. Sharks inflict strong top-down forces on lower trophic food webs, keeping prey populations healthy and in balance. If you remove sharks from the coral reef system, large predatory fish such as groupers thrive and predate upon all the herbivorous fish. With very few herbivores on the reef, macroalga can thrive and out-compete the corals, changing the coral reef to one dominated by algae.
2. They help remove the sick and injured
Sharks play a pivotal role in keeping populations that they prey on genetically healthy by removing the weak individuals. This means that any weak or mutated genes will not be passed onto future generations-and only the strongest will survive. They also remove sick and diseased animals, which is not only beneficial for the sharks as they exert less energy catching their prey, but is also fundamental in maintaining healthy oceans.
3. Sharks play an invaluable role in solving the climate crisis
Tiger sharks are known to protect and enhance blue carbon, the carbon stored in marine ecosystems, by preying on seagrass grazers. Seagrass is not only a precious ecosystem to a plethora of species, but it also plays a vital role in absorbing carbon through photosynthesis, capturing carbon from the atmosphere 35 times faster than tropical rainforests. When tiger sharks enter seagrass meadows to prey upon turtles, they prevent overgrazing in concentrated areas, resulting in an increase in the overall meadow mass.
4. Sharks are important to the economy
With a rapidly growing global market for diving and marine-based tourism, shark tourism can generate considerable economic value. A recent study by Cisneros-Montemayor et al, 2017 reports that the global shark diving industry generates $314 million per year, and directly supports 10,000 jobs. In the next 20 years, this is expected to double generating more than $780 million per year.
Shark tourism has the potential to benefit local communities by bringing money to their economy, and for most cases it appears more profitable to keep sharks alive than it is to fish them. Saving Our Sharks Foundation is working with local fishing communities to help them develop their own shark tourism business, find out more about how we work here.
It is crucial to remember that all species in the marine ecosystem are connected. If sharks were to disappear it would lead to a catastrophic domino effect. What happens to sharks, happens to everything else. And now you understand the value of sharks, what can you do to help? You can help by supporting our work with local communities that have taken shark conservation into their own hands. Together we are working to ensure sharks keep playing their integral role in the marine ecosystem forever.