Asked by: Aline Smith, London
Saltwater by itself doesn’t have any smell, but the things that live in it certainly do. The rather stale, sulphury smell is dimethyl sulphide, produced by bacteria as they digest dead phytoplankton. At low tide, you’ll also smell chemicals called dictyopterenes, which are sex pheromones produced by seaweed eggs to attract the sperm. And on top of all this is the ‘iodine’ smell of the sea, which is actually the bromophenols produced by marine worms and algae.
Get more fascinating Q&As from BBC Focus magazine by following @sciencefocusQA