Below the top few hundred metres, the deep sea is generally cold and dark all year round. Long-term studies suggest it's a very stable, unchanging environment.
Some seasonal shifts are coming to light, however.
Spring blooms of phytoplankton paint the sea surface in green swirls and send flurries of organic matter – known as ‘marine snow’ – into the deep, feeding many deep-sea animals.
A recent study also revealed that currents sweeping over the deep seabed are not steady and continuous, as previously thought.
Instead they’ve been observed speeding up, slowing down and switching direction through the year, showing just how much there is still to discover in the deep.
This article is an answer to the question (asked by Danielle Barlow, Newcastle) 'Does the deep sea have seasons?'
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