Ionic liquids are a relatively new class of salts with a wide range of favorable physical  and chemical properties , which  creates a lot of  industrial  interest.  This thesis examines whether they can be used as antifoulers on board of ships.  Metal plates were treated with different ionic liquids and exposed to seawater in the  port of Ostend during various periods.  It has been proven that they have anti - fouling properties in previous studies.  Nevertheless, this experiment shows that the treatment with ionic liquid has not  affected the amount of fouling on various metal plates.  Other potential sources are the secondary metabolites produced by soft corals,  actinobacteria and a number of seagrasses and mangrove plants. They exhibit  fouling properties. Whether these secondary metabolites can be used on board  of  ships has  yet  to be investigated.