March 10, 2016
Just as taxes ensure vital services to our communities, sharks are critical to the functioning of marine communities.
Also, just like taxes, some of us may not like sharks. In fact, we might prefer to avoid thinking about them. But without sharks, our marine communities would fall into disrepair.
Imagine civilization without taxes—think of all the systems that we rely on, from smooth roads to a reliable water supply. Sharks serve a similar purpose.
Sharks maintain the health of marine ecosystems by keeping fish populations in check. They prey on weak, unfit and unhealthy fish. They ensure the toughest survive and prime the genetic stock of fish populations with the strongest individuals.
They tear up carcasses of large marine mammals, such as whales and seals, and facilitate their rapid decomposition. This helps prevent disease from incubating and spreading.
Ultimately, sharks regulate the size of various marine populations. Without sharks, some species would become overpopulated and the impact on the ecosystem would be dire.
Researchers have found that the presence of tiger sharks in Hawaiian waters helps keep seagrass beds intact. As sea grass is a favorite meal for sea turtles, and in turn, sea turtles are a favorite meal for tiger sharks, tiger sharks prevent seagrass beds from being overgrazed.
This is important for two reasons. One, it takes seagrass beds a long time to grow, and they help stabilize the inshore sandy zones. Two, seagrass ecosystems are vital juvenile nurseries for many of our favorite fish.
Without these seagrass nursery grounds, we’d have less fish to eat—and livelihoods of Hawaiian fishermen would be at stake, too. Without the tiger shark keeping the sea turtle population in check, the seagrass beds would not thrive.
As with any ecosystem, there’s a critical balance that is important to maintain. Sharks are critical. They are vital—like taxes—to the ocean’s overall health.
And ours.