Happy “Sharktober”! Tis the season that white sharks begin to appear more often along our shores. There are over 400 species of sharks known to live all over the globe, in just about any marine habitat. Out of all of these sharks, white sharks are one of the most infamous predators—and we live along the “red triangle” where they can be found. In fact, in just the first week of October there have been several shark encounters off our coast as these creatures come closer to shore where people are still soaking in the last rays of our long California summer. Looking back through the years, a pattern of shark sightings during “Sharktober” starts to form.
Many think that sharks are scary and dangerous—some countries have even gone so far as to target them as a threat to public safety (as in Australia). Are sharks truly villains, or are they victims of some bad publicity? White sharks are apex predators, and teeth and all, actually play an important role in the ocean’s ecosystem.
Apex predators have few predators of their own. White sharks and other large sharks are sometimes taken by orcas, but otherwise have only to fear humans, who are by far their most deadly predators. As apex predators, sharks play a very important role in their ecosystem. By eating other (smaller) predators, such as seals and sea lions, sharks keep them in check. When apex predators are removed, their prey’s population expands—more seals and sea lions, means more fish being eaten. The effect ripples throughout the ecosystem, affecting every level of the food chain, with unexpected effects such as increased algae growth. Without these powerful predators, the ocean would be a very different place.
This month I am excited to celebrate sharks and learn more about these mysterious creatures. You can help sharks shake their scary reputations by busting some myths:
Track sharks as they move around the ocean and head over to share the waves with us:
http://www.expeditionwhiteshark.com/ <mobile app!>
Learn more about apex predators, with classroom activities: http://marinelife.about.com/od/glossary/g/apexpredator.htm