Ocean deoxygenation

Ocean deoxygenation is when the water in our oceans has less oxygen in it. This means that the creatures that live in the ocean can't breathe properly and it can hurt them and even kill them. When small creatures that live in the ocean don't have enough oxygen, they can die and that affects bigger creatures that depend on those little creatures for food. So, when there is less oxygen in the ocean it can hurt creatures of all sizes and even make some of them disappear.