Sharks Need Divers & Divers Need Sharks

By Katie Gerstle |

Rumour has it, there was a recent sixgill shark (Hexanchus griseus) sighting at Whytecliff Park, which is very fitting considering that we’re just wrapping up Shark Week!

For many years, Shark Week was strictly a source of entertainment that erred on the side of science fiction instead of science fact. Sharks, since the days of Jaws, are an animal that we happily sensationalize in films and mockumentaries. But more recently, Shark Week has taken on a new life as a both an informative source of shark knowledge, and a conservation call to action: Look how awesome these animals are; let’s take care of them.

While sharks only kill 4-12 people in the world each year (you’re more likely to be killed falling out of your own bed, which claims 1,600 poor chaps each year), humans kill a whopping average of 63 to 273 million sharks per year (the lower end of that spectrum is almost twice the current population of Canada). At this rate, Shark Week may soon have to air on the History Channel, because there’s only so many years that we can systematically deplete the oceans of an apex predator before they’re all gone.

But enough doom and gloom! Here are a few reasons why we actually need sharks in our lives, and in our dives.

1. Sharks improve the health of many fish populations.
It may seem counter-intuitive, but since sharks target the weak, sick, and dying individuals in their prey populations, they’re actually increasing the viability of those fish stocks. In the wild, the name of the game is conserving your energy, and not getting killed by something else. If a slow, dying fish is an easier target than a healthy, agile fish, a clever predator will choose to eat the one that delivers sustenance for the lowest cost. Conclusion: Sharks directly improve the robustness of all of their prey, which, as an apex predator with over 550 documented species worldwide, means that they are essentially controlling the health of our oceans.

2. Sharks keep underwater habitats in good shape.
Not only do sharks keep fish populations healthy, but they also maintain the quality of the habitats that both predator and prey call home. Instead of staying in one coral reef or eelgrass bed, fish will migrate to avoid their predators, giving the habitat time to rebound and grow. Without sharks, fish, turtles and other shark prey found in various waters, would efficiently mow down a reef or a kelp bed if they weren’t prompted to leave. In other words, if there is food in the fridge, there is no need to go to the grocery store – a sentiment that we can all relate to at one time or another.

3. Swimming with sharks can make you a better diver.
Huh?! What could a shark possible teach me about diving? Well, here’s one of the many mind-blowing things about sharks: They can sense your heartbeat. Better yet, they can tell the difference between a racing heart and a calm one. And as it turns out, a racing heartbeat is more likely to deter a shark than to attract one. So they key is to remain calm. In diving, we’re taught to relax, take easy breaths, and conserve energy (the familiar topic rears its head again! We’re not so different from our fishy friends, are we?). Keeping our heart rates in check keeps our air consumption down, allowing for more time underwater, and if we’re lucky, more time to spend with sharks.

Now the question remains, how can we help sharks?

1. Vote for sharks with your dollar.
A good place to start is to think about the seafood that you eat. Where does it come from? Was this seafood caught at the expense of other species (known as bycatch)? Was this seafood harvested in a way that won’t decimate the population so that I can buy it again in a month or a year from now? Ultimately, am I using my money to support a sustainable or an unsustainable system? If you’re unsure, consult any one of these guides to help you make a choice that helps your oceans: Seafood Watch, Ocean Wise, and SeaChoice, to name just a few.

2. Become a shark advocate.
Linking up with other like-minded divers is a great way to build a network of shark advocates. Getting involved with Project AWARE is one way to learn more about vulnerable populations and figure out how your dives can be put to good use! PADI also offers an AWARE Specialty Course on Shark Conservation that will combine your love of diving with the scientific backing to understand more about the problems that sharks face and why many shark species are considered threatened or endangered.