When the great white shark population decreased in North American coastal waters, it led to an increase in the population of their prey species, such as seals and sea lions. As a result, these prey species were overgrazing and causing damage to the kelp forests which served as important habitats and nurseries for many other marine species. The decline in kelp forests affected many species that depend on kelp for food and shelter. For example, abalone and sea urchins historically grazed on kelp forests, but their populations were significantly reduced in the absence of kelp. This led to many other indirect effects such as declines in rockfish, lingcod, and other commercially important fish species which rely on these grazers as a food source. Therefore, the decrease in great white shark populations had a cascading effect on the entire ecosystem of North American coastal waters.
