As of 2012, the port of Zeebrugge has granted price reductions to environment-friendly vessels that call at the coastal port. Nowadays, shipping companies can report all kinds of data concerning their vessels to the Environmental Ship Index (ESI) on a voluntary basis.
This index was introduced by the World Port Climate Initiative in 2010. The aim of this new index or standard is to persuade shipping companies worldwide to considerably reduce the emission of hazardous materials of their vessels. The index registers among others emissions of sulphur, nitrogen, fine particles and greenhouse gas.
Vessels that score high on this index can be rewarded, since they endorse sustainable shipping. Ports can decide autonomously to use the Environmental Ship Index in order to grant reductions on port dues.
The port authority Zeebrugge is taking action to start introducing price reductions for vessels that use LNG as fuel.in the future.