Ruling from the top-down: Sharks as Apex Predators and the Need for Better Management

by Tom Tascone, RJD Intern

An apex predator is defined as a predator residing at the top of the food web in its ecosystem.  Life at the top has its benefits – reigning supreme in its environment, the apex predator feeds on lower levels in the food chain and has no natural predators of its own, allowing it to enjoy the freedom that comes with being the hunter, not the hunted.  Many examples of apex predators exist in both terrestrial and marine habitats, and if you were to ask anyone, despite their scientific expertise, to name a marine apex predator, you would certainly get some type of shark as your most common answer.

The influence of apex predators like sharks on marine ecosystems, however, has been little studied.  Marine food webs are incredibly large and complex, and encompass a wide variety of species. Additionally, many of these species act as both predator and prey and interact with multiple other species in both capacities, complicating research that much further.  However, as anthropogenic (human-induced) changes to marine ecosystems through activities like commercial fishing continue to deplete many fish populations, sometimes upwards of 90%, growing concern has spurred new research in this area (Baum and Worm 2009).  Focusing on the potential effects that anthropogenic change can have on the structure of marine food webs, this research has identified just how important sharks are in their role as apex predators.

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