Ocean Facts for Kids
Deep-sea facts and ocean wonders
When a whale dies and sinks to the seafloor, it creates a 'whale fall' — a unique ecosystem that can support hundreds of species for up to a century. Bacteria, worms, sharks, and crabs all feed on different stages of the decomposing whale.
Tardigrades (water bears) found in ocean sediments can survive pressures over 6,000 atmospheres — far greater than the deepest ocean trench. They can also survive vacuum, radiation, and temperatures from near absolute zero to 150°C.
Male humpback whales sing complex songs that can last up to 20 hours, and all the males in the same ocean basin sing the same song at the same time. The song changes every breeding season and the changes spread like cultural trends.
The epipelagic or sunlit zone produces most of the fish that humans eat. Upwelling currents — which bring cold, nutrient-rich water up from depth — create the world's most productive fishing grounds, like those off Peru and Namibia.
The ratio of dissolved salts in ocean water is remarkably consistent everywhere on Earth, even though total salinity varies. This suggests the ocean has been efficiently mixed over millions of years.
Fresh water pouring into the North Atlantic from melting Greenland ice is diluting the salty, dense surface water that drives thermohaline circulation. Scientists warn that if circulation slows, it could trigger drastic climate changes across Europe and beyond.
Red tides are harmful algal blooms where certain algae multiply explosively, sometimes turning the water red or brown. The algae can produce powerful toxins that kill fish and shellfish and make seafood dangerous for humans to eat.
Ocean gyres are large systems of circular ocean currents driven by global wind patterns. Their centres tend to accumulate floating debris because currents flow toward them from all sides, creating the ocean's garbage patches.
Electric rays can generate electric shocks of up to 220 volts to stun prey and deter predators. Ancient Romans used them as a form of anaesthetic, pressing live electric rays against patients before surgery.
The marine iguana of the Galápagos Islands is the only lizard in the world that feeds in the sea. It dives up to 30 metres deep and sneezes out salt through special glands in its nose.