Updated: Nov 2, 2020
Sharks, especially great whites, are constantly being painted as bloodthirsty killers that lie in wait for unexpecting holiday goers to naively dive into the sea and right into their trap, so they can strike them in one fatal CHOMP! Following a generation that grew up with films like JAWS, this is somewhat understandable. However, when you look at the statistics it's surprising that people are still so fearful of them (even when they live nowhere near the sea) seeing as an average of only four people dies from shark incidents per year. Bees, wasps, dogs and snakes are responsible for more deaths in the US than sharks!
Fossil records show that sharks have been around for 400 million years. They have outlived dinosaurs and many other species alive today! With over 400 species of sharks, they are a hugely diverse group, that are highly adapted to their specific environments. Sharks play a key role in not only their habitat but also benefit the rest of the world in various ways - some of which you may never have thought of!
Here are 4 ways in which sharks contribute to keeping the world (and you) alive:
1. Maintaining the Oceans Populations
Sharks are apex predators in the food chain. They play a crucial role in maintaining the population of species below them in the food chain. This means when shark populations fluctuate so does the rest of the ecosystem. A study in Australia found that as the number of sharks declined, the number of mid-level predators like snappers began to increase which caused herbivorous fish to decrease. The decrease in herbivorous fish led to the reef becoming overwhelmed with algae, causing the reefs overall health and resilience to decrease. Additionally, sharks help to remove weak and sick individuals from a population which promotes species diversity by removing disadvantageous genes. So next time you are admiring a beautifully diverse reef, just remember that it's apex predators like sharks that have helped to keep that reef so stunning!
Beautiful reefs in Panglao, Philippines
2. Boosting Local Economies
The economic gain from fishing sharks is minimal in comparison to that of shark ecotourism. In Australia, the value of a single living whale shark is around UA$ 282,000, whereas the market value for whale shark meat in Taiwan is approx. US$11.80/kg. Across the globe, in Florida, the story is the same! A report by Oceana found that in 2016 shark-encounter divers generated $220 million and supported 3,700 jobs! When you look at the amount Florida made from shark fin exports in 2015 it is minimal, equating to little over $1 million. It is clear that a shark generates a huge amount of economic gain just by swimming in the ocean than when they are killed and sold for their meat and fins. Sadly, this hasn't stopped the capture and killing of sharks, it's estimated that 73 million sharks are killed annually for their fins.
A grey reef shark cruising through the waters in the Conflict Islands, Papua New Guinea
3. Reducing Climate Change
Carbon sinks are natural environments that absorb and store carbon from their surroundings and help to lower the concentration of carbon dioxide in the atmosphere. Seagrass, salt marshes and mangroves are some of the most important carbon sinks in the world, they store 'blue carbon' (which is carbon dissolved in the ocean). There has been a loss of 90% of the oceans top predators. This decline in sharks and other predators has caused the number of other animals in the food web to become overabundant. If species that feed on these carbon sinks become overabundant (like turtles who feed on seagrass) it would result in large amounts of carbon being released back into the ecosystem. If just 1% of the oceans blue carbon sinks were lost it would be the equivalent of 460 million tonnes of carbon being released annually! That's the same amount of carbon produces by 97 million cars!
Mangrove (left) and seagrass (right) are important blue carbon sinks
4. Inspiring the Development of Medical Materials
As you can see sharks are incredibly important for not only the health of the oceans but for the rest of the world too! Sharks are inspiring the development of materials to be used within hospitals! Contamination of surfaces within hospitals is an ongoing issue, surfaces can become contaminated with pathogens, some of which, have the ability to live for weeks or months before coming in contact with a person. How do sharks possibly come into this I hear you ask... Well, shark skin is highly adapted to prevent algae, barnacles and other organisms attaching to them. This adaptation has lead to the development of the 'Sharklet micropattern', It is a thermoplastic that has small bumps (too small for human eyes to see) which is thought to prevent the growth and spread of bacteria. A study found that MSSA and MRSA Bacterial contamination was reduced by 87-99% when Sharklet MP was used instead of normal smooth surfaces.
Hopefully, you can now see that sharks are a pretty big deal and their protection is imperative! Not only do they help keep the ocean a beautiful and diverse place, but they also help to slow down climate change and are even helping to inspire future medical materials! Next time you see a news report or TV show portraying them as mindless killing machines that should be irradicated to save the human race... just think of these four ways sharks are benefiting the world just by being themselves!