• Question: why does the sea appear to be darker in england than in tropical places?

    Asked by Maia to Imogen on 10 Mar 2015.
    • Photo: Imogen Napper

      Imogen Napper answered on 10 Mar 2015:

      It can be affected by a number of things!

      The colour of water has to do with both the things living in it and the dirt that’s stirred up in it.

      Lots of things affect how much life there is in the water, but the most obvious is the type of dirt that makes up the sea bed in the area. The sea bed near Florida is mostly sand, which doesn’t dissolve easily in the water. It sinks, and so you see mostly clear water. The warm water also helps keep down algae, which keeps the water from turning green.

      Further north, for example the UK, the clay soils turn the water turbid, and the cool water supports a lot of microscopic life forms. Together, they can turn the water green or brown.

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