When people remove fish from seagrass beds, it can lead to seagrass death. Algae and other epiphytes grow on seagrass blades and are regulated by grazing fish. Some of these algae-grazing fish are targeted by fisheries, and their disappearance allows the algae to grow out of control and to choke the seagrass. However, more commonly fisheries catch bigger fish species a couple of steps up the food web from algae-grazers. When these larger fish are removed from the ecosystem, their prey—the predators of algae-grazers—thrive, and they can quickly decimate algae-grazer populations. So overfishing of large fish indirectly causes algae to grow out of control and kill seagrass.