Modified on : 14 Feb 2019
![](https://www.institut-paul-ricard.org/wp-content/uploads/2018/05/PO-Sph.sph-SR-2008-3-P.Lelong-IOPR-web-935x500.jpg)
Open water offshore or nearer the coast is home to a range of organisms of all sizes: from plankton measuring a few hundredth of a millimetre to the 20-metre long fin whale; and from zooplankton – animals that have no locomotion and must drift with the currents – to the fastest and most agile swimmers like dolphins and swordfish.