This thesis investigates sustainability within maritime and port supply chains, with emphasis on ESG frameworks, performance measurement and the maritime energy transition. Through a critical literature review and structured questionnaires addressed to shipping, port and supply chain executives, the study examines how sustainability is adopted and measured across the sector, using the Port of Piraeus as its central case study.

Findings demonstrate a persistent gap between strategic sustainability commitments and operational implementation, particularly in ESG reporting, KPI monitoring and environmental performance measurement. Regulatory frameworks, investor pressure and digital technologies emerge as the primary drivers of sustainable transition, though organisational readiness remains inconsistent across the industry.

The thesis concludes that transforming the Port of Piraeus into a green, EU-compliant port requires coordinated investment in energy and digital infrastructure, institutional alignment and the systematic integration of ESG standards — moving sustainability from policy to practice.