Sharks have been swimming in our oceans for more than 400 million years; they were here before the dinosaurs. Being the first vertebrate predators, they succeeded in refining their aptitude and power over millions of years of evolution, allowing them to hunt as top predators and keeping ecosystems in balance. Today their populations are declining and pose a serious threat to the health of our ocean.
According to a report by Pew Charitable Trusts, a 70-80% decline in shark populations have been reported globally and some threatened shark species’ populations have been reduced by over 90 percent due to overfishing and increasing shark catch levels around the world for their fins. Over 100 million sharks are killed annually for the Asian delicacy shark fin soup. Many of these sharks are hooked, finned, and tossed overboard to drown alive. Science estimates that global shark populations could become extinct by mid century if this global fin trade continues at this rate.
So what would the ocean look like without this top predator? Removing them from the food web causes our whole marine structure to collapse. According to experts, the sea would most likely turn into a murky underwater swamp overpopulated by algae and jellyfish.
In healthy reef ecosystems, almost everything is efficiently consumed in the food web but when we begin to decimate the sharks, the food web completely changes in character and becomes uncontrolled. Sharks dine on smaller fish such as tuna, which in in turn eat even smaller, bottom-feeding species like scallops. Scallops survive mostly on algae. Without the control and balance from the top, these algae eating scallops would most likely collapse allowing algae to grow wild producing toxins that contaminate seafood and even lead to death in humans in extreme cases. Other harmful cases of algae blooms may not be toxic but as they decay will suck up all of the surrounding oxygen, clog the gills of fish and invertebrates, or smother coral reefs.
We deserve a healthy ocean full of sharks hunting the waters. Here’s what you can do to help:
- Release all sharks that are caught fishing
- Choose Sustainable Seafood, visit Seafoodwatch.org
- Support shark research conservation efforts such as Project Aware, Oceana, & Shark Angels. (Waterlust is an experimental project using media and apparel to engage you in marine science. Shop their shark collection to donate towards shark research and conservation efforts at the University of Miami.)