Ocean Facts for Kids
Deep-sea facts and ocean wonders
Where rivers meet the sea, the mixture of fresh and salt water creates an estuary — one of the most productive ecosystems on Earth. Estuaries act as nurseries for many species of fish and provide crucial feeding grounds for migrating birds.
Bottlenose dolphins develop unique whistle 'signatures' that act as individual names, and they use these signature whistles to call out to each other. This is one of the only known examples in the animal kingdom of animals naming each other.
Many deep-sea fish have enormous eyes relative to their body size so they can detect the faint traces of bioluminescent light in the deep ocean. Some, like the giant squid, have eyes as large as footballs.
Mangrove forests grow along tropical coastlines with their roots in the sea, providing a buffer against storms and protecting shorelines from erosion. Their dense underwater root systems also provide shelter for juvenile fish, crabs, and other creatures.
Scientists use sonar technology — which sends out sound pulses and measures the echo — to map the underwater landscape. We have more detailed maps of the surface of Mars than we do of Earth's own ocean floor.
The leatherback sea turtle is the world's largest turtle, reaching up to 2 metres in length and 900 kilograms in weight. It can dive to depths of over 1,000 metres and travel more than 20,000 kilometres across the ocean in a single year.
Kelp is a giant seaweed that can grow up to 60 centimetres per day, forming enormous underwater forests along rocky coastlines. These kelp forests provide shelter and food for hundreds of species, including sea otters, fish, and seals.
Every whale shark has a unique pattern of spots on its body, just as every human has unique fingerprints. Scientists use photographs of these patterns to identify individual sharks and track their movements across oceans.
The first people to reach the bottom of the Mariana Trench were Jacques Piccard and Don Walsh in 1960, descending in a specially built vessel called the Trieste. Film director James Cameron made a solo dive to the same spot in 2012.
Remora fish attach themselves to sharks, rays, and whales using a suction disc on the top of their head. They hitch a free ride and eat scraps from the host's meals, a relationship that helps them without harming the larger animal.