British media: Tiger sharks have another side to their ferocious predation and contribute to the balance of marine ecology

　　At Shark Bay, the westernmost point in Australia, at least 28 species of sharks swim through clear waters and undulating seagrass, the world's largest shark bay. Tiger sharks are regular visitors to the jagged bay of Shark Bay. These large predatory fish have 4.5-meter-long bodies that pass through seagrass and occasionally prey on majestic herbivorous manatees. While the presence of tiger sharks poses a threat to prey, these predators are essential to sustain the marine ecosystems in which both species survive.

　　Tiger sharks prey on marine macrofauna

　　The BBC reports that despite sharks' notoriety for humans, they are also powerful allies in curbing climate change.

　　It all goes back to the waves-waving seagrasses on shark bay shoals. Seagrass is the food of manatees and dugongs, which eat about 40 kilograms of seagrass every day, and green sea turtles also eat seaweed for a living.

　　Dugongs weigh up to 500 kilograms and are a rich food source for tiger sharks. By controlling the population of manatees, the tiger sharks of Shark Bay contribute to the prosperity of seagrass meadows. A thriving seagrass meadow stores twice as much carbon dioxide per square mile as terrestrial forests.

　　But globally, tiger shark populations are declining, including some in Australia. Tiger shark populations are estimated to have decreased by at least 71 per cent off the north-east coast of Queensland, Australia, largely due to overfishing and net sequestration. Fewer tiger sharks mean that herbivores eat more seagrass, which makes marine vegetation absorb less carbon. In the Caribbean and Indonesia, where shark populations are declining, overgrazing by herbivores such as sea turtles has seriously threatened seagrass habitat and caused seagrass to disappear by 90 percent, if not all.

　　The disappearance of seagrass not only means absorbing less carbon, but also makes it difficult for habitats to recover from weather events caused by extreme weather, such as heat waves.