Healthy oceans depend on shark populations to control other species’ populations and genetic diversity. The Earth Island Journal investigated current shark populations and determined that the ocean food web relies on shark populations to keep other species' populations (Shark 12). This event, known as trophic cascade, occurs when a top predator disappears from the food chain and the next trophic level (the animals the predators eat) overpopulate and eat all of their available prey and grasses. This leads to drastic problems within the ecosystem that take years to reverse. Additionally, Robert Days, zoologist at the University of Melbourne stated that if the shark population continued to shrink, their prey would overpopulate and eat larger
