Spain’s new marine fuel regulation could lead to shifts in bunker volumes between European ports if similar requirements are not introduced consistently across neighbouring markets, according to PortXchange. The maritime technology company pointed to developments in Rotterdam after the Netherlands introduced a binding decarbonisation obligation for marine fuel suppliers at the beginning of 2026. PortXchange said Rotterdam bunker sales fell by 648,399 tonnes during the first quarter of the year. Volumes reached their lowest level since 2009. Spain introduces supplier-side requirements Spain has now adopted Royal Decree 611/2026. According to PortXchange, the regulation follows a similar principle to the Dutch system by placing a binding obligation on fuel suppliers rather than vessel operators. The Spanish requirements apply to domestic cabotage shipping. The greenhouse gas intensity reduction requirement will start at 6.5% in 2027. It will gradually increase to 33% by 2040. Spanish ports will also be required to report annually on the fuel and electricity they supply, with volumes categorised by type. PortXchange points to Rotterdam experience PortXchange argues that differences between national regulations can influence where vessels purchase bunker fuel. The company said Belgium has delayed introducing an equivalent requirement. Germany has also excluded maritime fuel from its own implementation. According to PortXchange, bunker volumes have therefore shifted from Rotterdam towards ports without equivalent obligations. The company also said Rotterdam’s compliance-related bunker price premium over its nearest competitor had reached US$20-25 per tonne by September. “Netherlands played it straight. Belgium delayed. Germany opted out. And the volume did exactly what volume does when the rules aren’t the same next door: it moved,” said Sjoerd de Jager, Managing Director and Co-Founder of PortXchange. IMO discussions approaching PortXchange also linked