Ocean Facts for Kids
Deep-sea facts and ocean wonders
Sea urchins are covered in long, sharp spines that protect them from predators on the ocean floor. Some species also have tiny pincer-like structures between their spines that can deliver a venomous bite.
The ocean provides the primary source of protein for more than 3 billion people around the world. Fishing is one of the oldest industries in human history and remains vital to the economies of many coastal nations.
Below 1,000 metres, the ocean is called the midnight zone — completely devoid of sunlight, freezing cold, and under immense pressure. Yet extraordinary creatures such as giant isopods, anglerfish, and dumbo octopuses live here.
A red tide is a harmful algal bloom where certain types of algae multiply rapidly and turn the sea red or brown. The toxins they produce can poison shellfish and fish, harming wildlife and making seafood unsafe for humans to eat.
Polar bears are considered marine mammals because they spend most of their lives on sea ice and in the Arctic Ocean, hunting seals. They are excellent swimmers and can paddle continuously for more than 100 kilometres.
About 2.7 billion years ago, tiny ocean organisms called cyanobacteria began producing oxygen through photosynthesis for the first time. This event, known as the Great Oxidation Event, fundamentally changed the chemistry of Earth's oceans and atmosphere.
In some species of deep-sea anglerfish, the tiny male bites into the female's body and fuses with her permanently, sharing her bloodstream. He provides sperm while she provides nutrients, and he eventually loses most of his organs.
Sunken ships on the ocean floor quickly become artificial reefs, with corals, sponges, and fish colonising the wreck within years. Some historic wrecks are now more biologically diverse than the surrounding seafloor.
Penguins cannot fly in the air, but they are superb swimmers that use their wings as flippers. Some species can swim at speeds of up to 36 kilometres per hour, making them among the fastest of all seabirds.
At a depth of around 1,000 metres there is a layer of water called the SOFAR channel where sound can travel for thousands of kilometres with minimal loss of energy. During World War II, it was discovered that this channel could be used to locate downed pilots at sea.