TedEd: The sharks that hunt in forests

By Luka Seamus Wright

Most people don't imagine sharks hunting and living in trees. But marine forests cover 4.2 million square miles of the Earth, and many sharks live and find protection in the roots of mangroves, as well as hunt in seagrasses. They provide shelter to 35% of the world's shark population. Perhaps the most unique ecosystem is one created by the mangroves. Mangroves live both on land and at sea, and their unique roots house many animals. In order to live in this limbo, they have several adaptations. First, their seedlings develop in trees before dropping into the water in a semi-mature state and drifting to a location where they can take root. They use some form of skinny roots and prop roots to hold themselves above the water. These roots also have microscopic breathing pores that the mangroves use to take in oxygen and keep out saltwater. The roots often have filters for salt as well, while some species opt to store salt and excrete it. These trees form the foundation of ecosystems that house many organisms, as well as sharks. But grown, predatory sharks arent bad - they keep the numbers of other organisms in check so the ecosystem doesn't get overcrowded. Overfishing in recent years has placed many of these homes in peril, and humans need to fight in order to preserve them.