DOI: 10.5281/zenodo.15290424
title: A geospatial dataset of the Mediterranean Sea Sulphur Oxides Emission Control Area

description: ABSTRACT

Starting from May 1, 2025, the Mediterranean Sea is officially designated as an Emission Control Area (ECA) for sulphur oxides (SOx) under MARPOL Annex VI Regulation 14, as adopted by the International Maritime Organization (IMO). This designation introduces stricter regulations on sulphur emissions prohibiting ships operating within the Mediterranean Sea ECA from using fuel oils with a sulphur content exceeding 0.10% m/m. These regulations require vessels to either switch to low-sulphur fuels or implement exhaust gas cleaning systems. Data to support the shipping industry in meeting regulatory requirements is essential. Ηowever, given the higher cost of compliance, there remains a strong economic incentive for non-compliance, making digital and data-driven enforcement mechanisms equally important.

In this context, the accurate geospatial definition of the ECA is crucial for monitoring and enforcement activities. This dataset provides a geospatial representation of the proposed Med SOx ECA, derived from IMO document MEPC 78/11 and aligned with International Hydrographic Organization (IHO) definitions. It serves as a foundational geospatial reference dataset for maritime authorities, maritime industry,  policy makers, and researchers involved in emissions control and marine environmental governance in the Mediterranean region.
description: To produce the geospatial dataset of the Mediterranean Sea Sulphur Oxides Emission Control Area (Med SOX ECA), we utilized the official document of IMO submission MEPC 78/11. The spatial extent of the proposed Med SOX ECA follows the International Hydrographic Organization’s (IHO) definition of the Mediterranean Sea, modified according to the specific boundary constraint descriptions provided in annexes and charts of the MEPC 78/11 document. 

The Mediteranean base geometry was sourced from the Marine Regions database (Gazetteer ID: 1905), available at https://www.marineregions.org, and loaded into QGIS (version 3.32.0-Lima) using the WGS84 coordinate reference system (EPSG:4326). For easier management and reference, the Mediterranean Sea is geospatially subdivided into its 10 main subdivisions:





Adriatic Sea




Aegean Sea




Alboran Sea




Balearic (Iberian Sea)




Ionian Sea




Ligurian Sea




Mediterranean Sea – Eastern Basin




Mediterranean Sea – Western Basin




Strait of Gibraltar




Tyrrhenian Sea



The following series of three geoprocessing operations were applied to the Mediteranean base polygon area so it is aligned with the legal documents specifications:



The Mediteranean base polygon was adjusted to follow a straight line connecting the Mehmetçik Lighthouse (40°03'N, 26°11'E) and the Kumkale Lighthouse (40°01'N, 26°12'E), marking the entrance to the Dardanelles Strait.

The Mediteranean base polygon was constrained by the line joining Cape Trafalgar, Spain (36°11'N, 6°02'W) and Cape Spartel, Morocco (35°48'N, 5°55'W), which forms the western boundary of the defined Mediterranean SOx area (Strait of Gibraltar).

The Mediteranean base polygon was clipped to exclude the designated waiting area at the entrance of the Suez Canal, using the QGIS geoprocessing tools “Difference/Erase”. The rectangular polygon used to define the exclusion of the Suez Canal waiting area is bounded by the following four geographic coordinate pairs:



Point 1   Lat: 31°29'N   Long: 32°16'E

Point 2   Lat: 31°29'N   Long: 32°28'25"E

Point 3   Lat: 31°14'N   Long: 32°32'37"E

Point 4   Lat: 31°14'N   Long: 32°16'E




All modifications preserved geometric integrity and topological correctness. All files comply with the WGS84 global coordinate system (EPSG:4326).The final dataset is published in three widely accepted open format types: 



An interactive html map ready to download and visualize in any browser (med_sox_eca_interactive map.html)

An ESRI Shapefile format (med_sox_eca shapefiles.zip)

A geojson format (med_sox_eca geojson files.zip) 

A .png image for map preview (Map preview.png)
description: Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union nor the European Commission. Neither the European Union nor the granting authority can be held responsible for them.