Lisbon Agreement 1990: NE Atlantic Iberian-Moroccan oil-pollution cooperation

Background: Bonn 1983 + Helsinki 1992 European regional pattern

The Lisbon Agreement 1990 was conceived during the late 1980s as the third leg of a European regional sea cooperation triad on operational pollution response, alongside the Bonn Agreement 1983 for the North Sea (signed 13 September 1983, in force 1 September 1989) and the future Helsinki Convention 1992 for the Baltic Sea (signed 9 April 1992, in force 17 January 2000). The triad emerged from the post-Torrey Canyon 1967 consensus that no single coastal state could manage a transboundary tanker spill alone, and from the parallel IMO OPRC 1990 Convention negotiation that explicitly endorsed regional agreements as the preferred operational delivery mechanism under OPRC Article 7.

The architectural pattern across the three European regional regimes is consistent: a multilateral treaty between coastal states plus the European Communities (now European Union) as a sui generis regional party; a secretariat to coordinate the regime; zones of responsibility mapped onto national EEZs with joint zones at boundaries; mutual assistance during incidents; surveillance through aerial flights and increasingly satellite SAR imagery; information exchange through a shared communication system; and periodic ministerial review. Bonn’s Bonn Information System (BIS) and OTSOPA (Operational Sub-Group on Operational, Technical and Scientific Questions Concerning Counter Pollution Activities) provided the template, with Helsinki’s HELCOM Response Group and the planned Lisbon machinery deliberately patterned on the Bonn model.

What sets the NE Atlantic Iberian-Moroccan margin apart from the North Sea and Baltic is its east-Atlantic exposure: the Iberian coast faces the open Atlantic with deep-ocean approaches, the Galician fishing industry is the largest in Europe by tonnage and employs roughly 30,000 people directly, the Strait of Gibraltar funnels approximately 120,000 vessel transits per year through the western Mediterranean approaches with Cape Finisterre as the southern Atlantic-routing waypoint, and the Atlantic tanker traffic from the Persian Gulf, West Africa and the Caribbean concentrates along the Iberian rotor before splitting into Channel-bound and Mediterranean-bound flows. The volume and exposure made the third leg of European regional cooperation a public-policy priority even though it ultimately stalled on ratification.

A further driver was the Galician coast geography: a complex rias (drowned river-valley estuaries) coastline with extreme productivity for shellfish, fin-fish and seaweed harvesting, and an equally extreme vulnerability to oil contamination because of the long water-residence time inside the rias, the dependence of the regional economy on fisheries and aquaculture, and the political weight of the Galicia autonomous community within Spain. A serious spill off Galicia would deliver a regional economic shock that no single state could absorb alone, motivating multilateral response cooperation as a matter of strategic prudence.

1990 Lisbon signing + 35 years pending entry into force

The Cooperation Agreement for the Protection of the Coasts and Waters of the North-East Atlantic against Pollution was opened for signature at Lisbon on 17 October 1990 during a diplomatic conference convened by the Government of Portugal as the depositary. The full title in Portuguese is Acordo de Cooperação para a Proteção das Costas e Águas do Atlântico Nordeste contra a Poluição. The text comprises 23 Articles plus an Annex covering operational implementation details, with provision for subsequent operational manuals and amendments to be adopted under the standing parties’ machinery once the Agreement enters force.

Entry into force requires ratification by all five signatories. As of 2026 the status is:

• Portugal: ratified 1992, full party in waiting
• France: ratified 1992, full party in waiting
• Morocco: ratified 1995, full party in waiting
• European Union: approved by Council Decision 1993, full party in waiting
• Spain: signed but NOT YET ratified as of 2026

The Spanish ratification has been pending continuously since signature, roughly 35 years, making the Lisbon Agreement one of the longer-suspended modern multilateral environmental treaties. The pending status has not blocked technical cooperation under EU competence and through bilateral channels, but it has prevented formal entry into force, formal Secretariat designation, and the formal adoption of operational manuals and zones of responsibility under the Agreement’s own machinery.

The continuous non-entry-into-force has produced a peculiar legal-political situation in which the parties cooperate in practice through EU instruments, EMSA services and bilateral arrangements but not under the Agreement itself. The pattern is reminiscent of other modern multilateral instruments where ratification gaps have spanned decades before the instrument finally enters force or is superseded; the HNS Convention 2010 is the closest comparator in maritime law.

The 5 signatory parties: France, Morocco, Portugal, Spain, EU

The five signatories plus the European Union are listed below with their respective coastlines and the rationale for their inclusion.

Portugal is the host state for signature and the depositary. Portugal’s mainland coast extends approximately 943 km from the Spanish border at the Minho river south to the Algarve terminus at the Spanish border at the Guadiana river. The Atlantic islands of the Azores and Madeira add substantial Exclusive Economic Zone in the open Atlantic, although the geographical scope of the Agreement is restricted to the mainland margin. Portugal’s principal pollution-response capacity is concentrated in the Direção-Geral da Autoridade Marítima (DGAM) and the Marinha Portuguesa (Portuguese Navy) with response equipment held at Lisbon (Alcântara), Sines, Leixões and Faro. The Instituto Hidrográfico in Lisbon provides oceanographic and drift-modelling support.

Spain is the most economically exposed of the parties because of the Galician fishing industry, the Bay of Biscay Basque coastal infrastructure, and the Andalusian Atlantic coast at Cádiz and the approach to the Strait of Gibraltar. Spain’s mainland Atlantic coast (Galicia plus Asturias plus Cantabria plus Basque Country plus Andalusian Atlantic) extends approximately 1,800 km. The Sociedad Estatal de Salvamento Marítimo (SASEMAR) operates the principal response capacity from a network of base stations at A Coruña, Vigo, Gijón, Santander, Bilbao and Cádiz, with maritime rescue coordination centres at the same locations. Repsol, Cepsa and the major Spanish refining operators provide industry response capacity at refinery locations.

France is included for the Bay of Biscay French margin including the Brittany Atlantic and the Aquitaine coast south to the Spanish border at Hendaye. The French coastline within the Lisbon polygon (Brittany Atlantic plus Aquitaine) extends approximately 800 km. France is also a Bonn Agreement party for the Channel and northern Atlantic margin north of approximately 48° 30’ N, creating an overlapping French exposure to both regimes. The Préfecture maritime de l’Atlantique at Brest and the CEDRE technical institute at Brest provide the operational and technical core. The Marine Nationale Atlantic Squadron operates response vessels at Brest and Lorient.

Morocco is included for the Atlantic Moroccan coast from the Spanish enclave at Ceuta (technically Mediterranean) and the Tangier Atlantic outlet south to the Mauritanian border at the Saharan Atlantic terminus. The Moroccan Atlantic coast extends approximately 1,800 km including the Western Sahara stretch. The Direction de la Marine Marchande under the Ministry of Equipment, Transport, Logistics and Water is the principal CNA, with the Royal Moroccan Navy providing operational lift. The Office National des Hydrocarbures et des Mines (ONHYM) has interests in pollution response in connection with offshore exploration. Morocco’s inclusion gives the Agreement an Africa-bridging character that distinguishes it from Bonn (purely European) and Helsinki (Baltic states only).

European Union is a contracting party in its own right under EU competence for marine environmental protection. The EU’s regional party status mirrors its role in Bonn, OSPAR and Helsinki. The European Commission, specifically the Directorate-General for Environment (DG ENV) and the Directorate-General for Mobility and Transport (DG MOVE), would represent the Union, with operational support from EMSA based in Lisbon (the same city as the Agreement signature, providing geographic continuity).

The combined coastal exposure across the five signatories is approximately 5,300 km of Atlantic coast, with the inland Mediterranean approaches at the Strait of Gibraltar adding Spanish exposure beyond the strict polygon. The EEZ area is approximately 2.4 million km² including the deep-Atlantic margins.

Spain’s pending ratification: zones-of-responsibility concerns

The principal substantive obstacle to Spanish ratification has been the question of zones of responsibility at the French-Spanish Atlantic boundary in the Bay of Biscay, and at the Spanish-Moroccan boundary in the Strait of Gibraltar approaches and the Western Sahara Atlantic. Spain’s negotiating concern in 1990 and subsequent decades has been that the proposed Lisbon zones overlap or intersect with:

• The Bonn Agreement 1983 zones in the Channel Western approaches boundary at approximately 48° 30’ N, where French and Bonn-area UK responsibilities meet Spanish-area Lisbon responsibilities
• The 1995 French-Spanish Bay of Biscay bilateral arrangement which already allocates response responsibility between the two states without reference to Lisbon Agreement zones
• The Strait of Gibraltar transit traffic which engages the Barcelona Convention REMPEC Mediterranean response regime and the bilateral Spanish-Moroccan arrangements at the Strait
• The Western Sahara Atlantic margin, where the political-legal status of Western Sahara as a non-self-governing territory complicates Spain’s recognition of Moroccan sovereignty over the proposed Lisbon zone

Successive Spanish governments have taken the position that ratification can be revisited once the zones of responsibility are clarified through supplementary instruments or bilateral memoranda of understanding. The 2024 Spanish parliamentary review, in which the Comisión de Asuntos Exteriores of the Congreso de los Diputados examined the dossier, declined to recommend ratification pending technical clarification of the zone overlap with Bonn.

A secondary concern has been the financial contribution scale. Under draft scale-of-contributions arrangements modelled on Bonn, Spain would carry the largest share among the four state parties, reflecting the longest Atlantic coastline within the polygon and the highest GDP among the Atlantic-only signatories. Spanish fiscal positions through the European debt crisis (post-2010) and the COVID recovery (post-2020) made commitment to a new multilateral budget item politically difficult.

A third concern has been operational duplication with EMSA services (CleanSeaNet, SafeSeaNet, SOSRV access) that already deliver substantial response capacity to Spanish waters under EU instruments. The argument has been advanced in Madrid policy circles that EMSA delivers operational equivalence to a formally entered-into-force Lisbon Agreement, although the legal symmetry is incomplete because EMSA does not provide a formal inter-state mutual assistance framework and does not formally engage Morocco.

Geographical scope: Cape Finisterre to Senegal-Mauritania

Article 2 of the Lisbon Agreement defines the geographical scope as the coasts and waters of the North-East Atlantic Ocean from Cape Finisterre in north-west Spain (approximately 42° 53’ N, 9° 16’ W) south to the Senegal-Mauritania border (approximately 16° 04’ N). The polygon extends from the high-water line seaward to the outer limit of each party’s Exclusive Economic Zone, with the deep-ocean Atlantic approaches included to the EEZ outer boundary at approximately 200 nm from baselines.

The northern boundary at Cape Finisterre is set to interface with the Bonn Agreement 1983 geographical scope which extends south from the Channel Western approaches at approximately 48° 30’ N. There is therefore a gap between the Bonn southern boundary at 48° 30’ N and the Lisbon northern boundary at Cape Finisterre at 42° 53’ N, covering the southern Bay of Biscay French waters between Hendaye and Île de Ré. This gap is filled informally through French dual-membership in both regimes (when Lisbon enters force) and through the 1995 French-Spanish Bay of Biscay bilateral arrangement. The pragmatic effect is that French response in the southern Bay of Biscay is led by France under Bonn doctrine for incidents north of approximately 46° N and under Lisbon doctrine (when in force) for incidents south of approximately 46° N, with case-by-case coordination at the boundary.

The southern boundary at the Senegal-Mauritania border at 16° 04’ N is the northern limit of the Abidjan Convention 1981 which covers the West African Atlantic margin south to Cape Agulhas in South Africa. The two regimes are intended to be operationally complementary, with cross-boundary cooperation through bilateral arrangements between Morocco (Lisbon) and Mauritania (Abidjan).

The polygon includes the major shipping lanes, the principal fishing grounds, and the offshore exploration prospects across the Iberian-Moroccan margin. Notable features within the polygon are the Galician rias (Ría de Vigo, Ría de Pontevedra, Ría de Arousa, Ría de Muros, Ría de Corcubión, Ría de Camariñas, Ría de Cedeira, Ría de Ferrol, Ría de Ares, Ría de Betanzos, Ría de A Coruña), the Bay of Biscay Basque-Aquitaine coast, the Lisbon-Cascais marine approach, the Algarve-Cadiz Gulf, the Strait of Gibraltar Atlantic approach, the Atlas-Atlantic Moroccan margin, and the Western Sahara Atlantic continental shelf.

Article 1: cooperation framework

Article 1 of the Lisbon Agreement establishes the fundamental cooperation framework: the parties agree to cooperate in cases of pollution incidents from oil and other harmful substances that affect or threaten to affect the coasts and waters of the North-East Atlantic within the geographical scope of Article 2. Cooperation extends to prevention, preparedness, response and post-incident recovery.

The Article 1 wording is closely modelled on Bonn Agreement 1983 Article 1, with appropriate adjustment for the NE Atlantic geographical context. The substantive scope covers:

• Crude oil and refined petroleum products from tankers, bunkers, terminals and offshore installations
• Hazardous and Noxious Substances (HNS) as defined by reference to MARPOL Annex II, the IBC Code, and the IMDG Code, in line with the IMO OPRC-HNS Protocol 2000 scope
• Other harmful substances which by reference to national legislation and EU instruments are deemed to require cooperative response

Article 1 obligations are activated by an incident which is defined to include discharge or release that has occurred, plus threatened discharge or release where prompt action is required to prevent or mitigate. The threatened-incident inclusion is significant because it brings precautionary action (for example pre-positioning equipment near a stricken tanker not yet leaking) within the cooperation framework.

The prevention dimension of Article 1 is more developed than in Bonn, reflecting the 1989 negotiating moment when risk-based prevention doctrine was rising in the IMO under MARPOL Annex I revisions and the developing Port State Control regime. Lisbon Article 1 explicitly references cooperation on preventive measures including traffic separation, pilotage in restricted waters, inspection of tankers transiting the polygon, and information exchange on substandard ships.

Article 4: zones of responsibility

Article 4 establishes the zones of responsibility model. The polygon is divided into national zones corresponding broadly (but not exactly) to each party’s Exclusive Economic Zone with adjustments for historical waters, offshore islands, and transit corridors. The parties contemplate joint zones in three principal areas:

• The Bay of Biscay French-Spanish boundary at the maritime border west of Hendaye-Hondarribia, where Bonn and Lisbon machinery would interact
• The Strait of Gibraltar Atlantic approaches at the Spanish-Moroccan boundary, where the Barcelona Convention REMPEC Mediterranean machinery would interact for spills propagating into the western Mediterranean
• The Moroccan-Mauritanian boundary at the Western Sahara Atlantic terminus, where the Lisbon and Abidjan regimes would interact

The zones-of-responsibility map is to be published in a Memorandum of Implementation annexed to the Agreement once entered into force, with periodic updates to reflect EEZ adjustments and new bilateral arrangements. As of 2026, the map has not been formally adopted because the Agreement has not entered force, and the de facto operational allocation runs through bilateral and EU instruments instead.

The Article 4 model has a lex specialis relationship with the more general UNCLOS Article 211 flag-state and coastal-state jurisdiction principle. Once the Agreement enters force, the coastal state in whose zone a spill occurs would be the lead state, and other parties would become assisting states under Article 6 mutual assistance once a request is made or once the lead state declares a Tier 3 response.

The non-entry-into-force has had the practical effect that no formal Lisbon zones map exists. The de facto allocation runs along EEZ lines as recognised by the parties at the time of any specific incident, with overlapping or contested boundaries (notably the Spanish-Moroccan Strait of Gibraltar and Western Sahara areas) handled through ad-hoc diplomatic channels.

Article 5: surveillance

Article 5 addresses surveillance of the polygon. Each party undertakes to maintain or develop surveillance capacity sufficient to detect pollution incidents in its national zone in a timely manner. Surveillance includes:

• Aerial surveillance by maritime patrol aircraft operating from coastal bases
• Vessel-based surveillance during routine maritime patrols by coastguard, naval and fisheries-protection vessels
• Satellite surveillance through the developing EMSA CleanSeaNet service from 2007 onwards
• AIS-based vessel monitoring through the developing EMSA SafeSeaNet infrastructure
• Coastal observation networks including lighthouses, port-authority observation, and citizen reporting

The Article 5 surveillance obligation is soft in formulation: each party undertakes to develop capacity proportionate to its means and to share the results with other parties through the cooperation system. The Article does not specify minimum hours of aerial surveillance, sortie counts, or satellite coverage frequency. The looseness reflects the 1990 negotiating compromise between France and Portugal (with substantial existing surveillance capacity through the Marine Nationale and Marinha Portuguesa) and Morocco (with developing capacity).

In practice, the surveillance gap left by Lisbon’s non-entry-into-force has been substantially filled by EMSA CleanSeaNet (Sentinel-1 SAR coverage of the Iberian-Moroccan margin), SafeSeaNet (AIS-based vessel monitoring), and national capacity on a stand-alone basis. The Bay of Biscay and Galician margin are covered approximately 3 to 6 times per week by Sentinel-1 SAR, with detection sensitivity comparable to the Bonn area (~0.5 to 1 µm slick thickness under favourable conditions).

Article 6: mutual assistance

Article 6 establishes the mutual assistance regime. A party requiring response support may request assistance from any other party, and the requested party is obliged to consider the request promptly and to provide assistance to the extent possible given its own operational commitments. Assistance includes:

• Personnel with relevant expertise (technical, operational, administrative)
• Equipment including booms, skimmers, dispersant aircraft, response vessels, dispersant stockpiles
• Expertise including scientific advice, drift modelling, dispersant guidance, shoreline-response doctrine
• Logistical support including port reception, fuel, accommodation, rapid customs clearance

The financial framework is set out in Article 6(3) with the default rule that the requesting state reimburses the assisting state for actual costs incurred at agreed standard rates. Equipment loans are usually free of charge for short deployments. Where the polluter is identified and pursued for civil liability under the CLC 1992 or the Bunkers Convention 2001, the assisting state’s costs are typically claimable against the polluter’s insurer through the lead state’s claims process.

Mobilisation timelines under Article 6 are not formally specified in the Agreement text but the Operational Implementation Manual (drafted but not formally adopted because the Agreement has not entered force) contemplates the Bonn-modelled standard: a request acknowledged within 2 hours, an initial assistance package committed within 6 hours, and the first equipment or personnel typically en route within 12 to 24 hours.

The non-entry-into-force has meant that formal Article 6 requests have never been made. Operational mutual assistance during incidents (notably Erika 1999 and Prestige 2002) has run through bilateral channels (France-Spain, Portugal-Spain), through EU civil protection mechanisms (the EU Civil Protection Mechanism established in 2001, formalised in 2013 as Decision 1313/2013/EU), and through EMSA SOSRV deployment. The substantive cooperation pattern has occurred in practice, but not under the Lisbon framework itself.

Secretariat (would be): European Maritime Safety Agency (EMSA)

The European Maritime Safety Agency (EMSA) is the proposed Secretariat of the Lisbon Agreement once it enters force. EMSA is headquartered at Lisbon (Cais do Sodré), providing geographic continuity with the Agreement signature city, and is the EU agency dedicated to maritime safety, pollution preparedness and response, and maritime traffic monitoring.

EMSA was established by Regulation (EC) No 1406/2002 in the wake of the Erika 1999 disaster (the Erika I Package of 2001 and the Erika II Package of 2002), with its mandate substantially expanded by the Maritime Safety Package III (Erika III Package) of 2009 covering eight legislative instruments including the EMSA founding regulation amendments. EMSA’s principal services relevant to Lisbon Agreement implementation are:

• CleanSeaNet satellite oil-spill detection (operational since 2007)
• SafeSeaNet vessel monitoring and reporting system
• Stand-By Oil Spill Response Vessels (SOSRVs) under five-year contracts with private operators, with several SOSRVs covering the NE Atlantic Iberian margin
• THETIS Port State Control inspection database
• EMCIP European Marine Casualty Information Platform
• LRIT Long-Range Identification and Tracking infrastructure
• Maritime Support Services including drift modelling, dispersant advice and operational support during incidents
• Training and exercises for Member State CNAs

EMSA’s Lisbon location was selected in 2003 by the European Council as part of the post-Erika institutional response, with the explicit recognition that the city’s connection to the 1990 Lisbon Agreement gave a fitting symbolism. The agency has approximately 300 staff and an annual budget of approximately €100 million as of the mid-2020s. The Lisbon Agreement Secretariat function, when the Agreement enters force, would be a discrete activity within EMSA’s broader mandate, supported by the existing CleanSeaNet, SafeSeaNet and operational-support infrastructure.

Until the Agreement enters force, EMSA cannot formally hold Secretariat functions, but it operates the operationally equivalent services through its EU mandate. The hybrid arrangement has been workable in practice but lacks the formal multi-party governance that the Agreement contemplates, and Morocco (a non-EU state) has access to EMSA services only through specific bilateral arrangements rather than as a full beneficiary.

Aragon 1989 grounding precursor incident

The Aragon grounding occurred on 29 December 1989 when the 96,000 dwt Spanish-flag tanker grounded off the Galician coast during heavy weather, releasing approximately 24,000 tonnes of fuel oil cargo. The incident occurred in the year preceding the 1990 Lisbon signing and contributed to the political momentum behind the negotiation.

The Aragon response was led by Spain through the SASEMAR predecessor agencies and the Marina Mercante, with technical advice from CEDRE and operational support from France and Portugal under bilateral arrangements. The total response cost was approximately €60 million (in 2026 equivalent), borne in large part by Spain pending recovery from the cargo insurer under the CLC 1969 and Fund 1971 instruments then in force.

The Aragon incident exposed several gaps that the Lisbon Agreement was intended to address:

• Limited Spanish response capacity at the time of the incident, with insufficient stocks of boom, skimmers and dispersant for a 24,000-tonne spill
• Slow international response because no formal multilateral framework existed (Spain was party to the IMO instruments but not to a regional response agreement for the Atlantic)
• Coordination gaps between coastguard, naval, fisheries and environmental agencies on the Spanish side
• Information exchange gaps with Portuguese, French and Moroccan authorities for spill trajectory and shoreline preparation

The incident was discussed at the 1990 Lisbon negotiating conference as a case study of the response gaps the Agreement would close. The Galician fishing community’s economic loss in the months following the incident, combined with the regional political weight of Galicia within Spain, contributed to the political consensus for the Agreement’s substantive scope.

A particularly painful aspect of the Aragon response was the shoreline impact along the Galician coast which damaged shellfish, seaweed and finfish harvesting in the rias for the 1990 fishing season, with cumulative economic losses estimated at approximately €100 million in 2026 equivalent. The Galician fishing cooperatives (confrarías) became advocates for a stronger response framework, contributing to the Spanish negotiating position at Lisbon.

Erika 1999 (Brittany) ~20,000 t spill

The Erika sinking occurred on 12 December 1999 in the Bay of Biscay approximately 70 km south of Penmarc’h, Brittany. The 37,283 dwt Maltese-flag tanker, built 1975, broke in two during a storm with 9-metre seas and Force 9 winds, releasing approximately 20,000 tonnes of No. 6 heavy fuel oil cargo of the Italian Total Fina charterer. The forward section sank to approximately 120 m depth and the aft section sank to approximately 120 m depth several hours later.

The technical setting of the incident was within the Bonn Agreement 1983 geographical scope (north of approximately 48° 30’ N at the time of structural failure, although drift trajectory south-east took the slick into the Lisbon polygon), making Erika a Bonn incident for response leadership. France was the lead state through the Préfecture maritime de l’Atlantique at Brest, with substantial international assistance including UK MCA personnel and equipment, Belgian and Dutch boom and skimmer support, and EMSA-precursor (then DG Environment) coordination.

The shoreline impact was severe along approximately 400 km of Brittany coast and the Vendée coast, with 150,000 to 300,000 seabirds killed (especially common guillemots and razorbills), and shoreline cleaning operations extending into 2001. The total response cost was approximately €220 million (2026 equivalent). The incident produced major political shock in France and across the EU, leading directly to:

• The Erika I Package of EU maritime safety legislation in 2001 (Port State Control reform, double-hull tanker mandate acceleration, Classification Society reform)
• The Erika II Package in 2002 (EMSA founding regulation, MARPOL Annex I phase-out acceleration of single-hull tankers, traffic monitoring directive)
• The Erika III Package in 2009 (eight legislative instruments expanding EMSA mandate, accident investigation framework, classification society liability, civil liability for shipowners)

The Erika incident also exposed the gaps that Lisbon would formally address but did not because of non-entry-into-force. The trajectory analysis showed that within 72 hours of the sinking the slick had migrated into Spanish-Galician waters, requiring de facto Franco-Spanish cooperation outside any formal regional framework. The bilateral 1995 Bay of Biscay arrangement provided some structure but lacked the multilateral and EMSA-level support that a fully implemented Lisbon Agreement would have delivered.

Prestige 2002 (Galicia) ~63,000 t spill, 11 deaths, 600+ km coast

The Prestige sinking is the defining incident of the post-Lisbon-signature era and the largest oil spill in European waters since the Amoco Cadiz 1978. The 42,820 dwt Bahamas-flag tanker, built 1976 in Japan, suffered hull failure on 13 November 2002 during a storm approximately 30 km off the Galician coast at Cape Finisterre, with structural cracking and progressive flooding. The vessel was carrying approximately 77,000 tonnes of heavy fuel oil cargo for the Russian shipper Crown Resources.

The Spanish authorities denied port of refuge to the stricken vessel, ordering it offshore, and Portuguese authorities likewise denied refuge. The vessel drifted south-westward through Spanish, Portuguese and finally international Atlantic waters for approximately 6 days, with progressive cracking and oil release, before breaking in two on 19 November 2002 approximately 240 km west of Cape Finisterre and sinking to approximately 3,500 m depth. The total release into the marine environment was approximately 63,000 tonnes at the surface plus approximately 14,000 tonnes retained in the sunken sections (subsequently recovered through deep-water capping operations in 2004).

The shoreline impact was catastrophic:

• Approximately 600 km of Spanish coast contaminated, principally Galicia but extending to Asturias and Cantabria
• Approximately 400 km of French Aquitaine coast contaminated (the slick reached Brittany and Aquitaine through northward drift over weeks)
• Approximately 200 km of Portuguese coast contaminated, principally the northern coast at Viana do Castelo, Porto and Aveiro
• Approximately 300,000 seabirds killed (principally common murres, razorbills and shags)
• 11 deaths during response operations, principally fishermen and volunteer cleanup workers (drowning, vehicle accidents, exhaustion)
• Approximately €2.5 to 4 billion total economic damage (2026 equivalent), with substantial losses to the Galician fishing industry

The political and legal aftermath was protracted. The vessel’s master, Apostolos Mangouras, was held in Spanish custody for several months and ultimately convicted in 2016 (after multiple appeals) of disobeying authorities (a relatively minor charge). The Spanish state sued the American Bureau of Shipping (ABS) in US federal court for negligent classification, ultimately unsuccessfully (2014 Second Circuit decision). The CLC 1992 / Fund 1992 compensation regime paid approximately €600 million in claims, with Spain contributing additional national funds. The total recovery from all sources was a fraction of the estimated economic damage.

The Prestige incident directly highlighted Lisbon’s non-implementation. The Spanish refusal of port of refuge, replicated by Portugal, derived from the absence of clear multilateral framework on places of refuge and stricken-vessel handling that a fully implemented Lisbon Agreement might have provided. The de facto multilateral response that did occur ran through EU emergency cooperation channels (then in development), through bilateral channels with France, and through the IMO OPRC framework rather than a regional Lisbon framework.

Post-Prestige EU response: Maritime Safety Package III 2009

The Maritime Safety Package III (Erika III Package) was adopted by the EU in 2009 as the post-Prestige institutional response, complementing the earlier Erika I (2001) and Erika II (2002) packages. The Package consisted of eight legislative instruments:

• Directive 2009/15/EC on common rules and standards for ship inspection and survey organisations
• Regulation (EC) 391/2009 on common rules and standards for ship inspection and survey organisations (the Recognised Organisation Regulation)
• Directive 2009/16/EC on Port State Control (the Paris MoU compatible regime)
• Directive 2009/17/EC on the EU Vessel Traffic Monitoring and Information System (SafeSeaNet establishment)
• Directive 2009/18/EC on accident investigation in the maritime transport sector (EMCIP establishment)
• Regulation (EC) 392/2009 on the liability of carriers of passengers by sea (Athens Convention 2002 implementation)
• Directive 2009/20/EC on the insurance of shipowners for maritime claims (P&I insurance mandatory minimum)
• Directive 2009/21/EC on compliance with flag state requirements

The Package substantially strengthened EU competence in the maritime safety domain that the Lisbon Agreement contemplates regional cooperation on. Directive 2009/17/EC in particular established the legal basis for places of refuge decisions by Member States, addressing the most painful operational gap exposed by Prestige (port-of-refuge denial).

In substantive effect, the Erika III Package delivered through EU instruments much of what a fully implemented Lisbon Agreement would have delivered through multilateral cooperation. The Spanish, French and Portuguese coastal states gained mandatory places of refuge arrangements, mandatory VTMS monitoring, mandatory accident investigation, mandatory P&I insurance for vessels in EU ports, and reformed Port State Control under the harmonised regime.

The post-Prestige EU response illustrates the substitution dynamic that has kept the Lisbon Agreement formally non-implemented for 35 years: where the substantive cooperation gap exists, the EU has filled it through Council and Parliament legislation rather than through ratification of the multilateral instrument. The dynamic has worked operationally for the EU coastal states, less well for Morocco as a non-EU party.

EMSA emergency response capability + CleanSeaNet

EMSA’s emergency response capability has developed substantially since the agency’s founding in 2002, particularly after the Erika III Package in 2009. The principal components are:

• Stand-By Oil Spill Response Vessels (SOSRVs) under five-year contracts with private operators (Boluda, Multraship, Oceanique Marine, others). As of the mid-2020s, approximately 18 SOSRVs are contracted across European waters, with several covering the NE Atlantic Iberian-Moroccan margin from bases at Lisbon, Vigo, A Coruña, Sines and Algeciras. Mechanical recovery capacity per SOSRV is approximately 300 to 800 m³/day depending on vessel and conditions
• Equipment Assistance Service providing booms, skimmers, dispersant aircraft and other equipment on a rapid deployment basis to Member State CNAs upon request
• Maritime Support Services providing technical support including drift modelling (Lagrangian particle tracking), dispersant advice, salvage advice and operational coordination during major incidents
• Pollution Response Training for Member State CNA personnel, including OTSOPA-style joint exercises, table-top exercises, and operational doctrine development
• CleanSeaNet satellite oil-spill detection

The CleanSeaNet service operates SAR-based slick detection from the Sentinel-1 Copernicus constellation (since 2014, replacing earlier Envisat ASAR), augmented by Sentinel-3 (visible and IR) and commercial SAR providers. Coverage of the NE Atlantic Iberian-Moroccan margin is approximately 3 to 6 times per week depending on latitude and season, with detection sensitivity at approximately 0.5 to 1 µm slick thickness under wind conditions of 3 to 8 m/s. Detected slicks generate alerts within 30 minutes of satellite pass, routed to the coastal state CNA for verification.

The CleanSeaNet detection rate over the Iberian-Moroccan margin has been approximately 300 to 500 detected slicks per year through the 2020s, of which approximately 40 to 60% have been verified as oil pollution upon coastal-state follow-up (the remainder being natural phenomena, biogenic slicks, or false positives from sensor noise). The verified slicks have driven enforcement action against undeclared discharges by transiting tankers, with approximately 20 to 30 prosecutions per year across Spain, Portugal, France and Morocco.

The CleanSeaNet service substitutes for the Article 5 surveillance obligation that the Lisbon Agreement contemplates but cannot formally activate. The substitution is operationally satisfactory for the EU parties but is delivered through EU instruments rather than Lisbon Agreement governance, leaving Morocco with formal gaps in access that have been filled through specific bilateral arrangements.

SafeSeaNet vessel monitoring system

The SafeSeaNet system is the EU’s vessel monitoring and reporting system, established by Directive 2009/17/EC (Erika III Package) and operated by EMSA. The system collects and shares AIS (Automatic Identification System) data, port arrival and departure notifications, hazardous cargo notifications, incident reports and pollution alerts across EU Member States.

SafeSeaNet’s principal data flows include:

• AIS-derived vessel positions with approximately 1.5 million position reports per day across European waters
• Port arrival notifications filed by ships’ agents under Directive 2002/59/EC as amended
• Hazardous cargo notifications under MARPOL and the IBC/IMDG Codes
• Notifiable incidents including pollution, accident and casualty events
• Port State Control intersection data through THETIS integration

For Lisbon Agreement purposes, SafeSeaNet provides the vessel monitoring infrastructure that Article 5 surveillance and Article 6 mutual assistance contemplate. A pollution incident in Galician waters can be cross-referenced with SafeSeaNet AIS history to identify candidate polluters within 6 hours, and the AIS-Slick correlation technique (developed by EMSA and Bonn Agreement parties jointly) achieves approximately 70 percent identification rates for slicks observed within 6 hours of generation.

SafeSeaNet covers the EU member states including Spain, Portugal and France, but does not formally cover Morocco because Morocco is not an EU member state. Morocco has access to SafeSeaNet data on a bilateral basis under the EU-Morocco Association Agreement, with periodic data exchanges but not real-time access. The gap is one of the practical effects of Lisbon’s non-entry-into-force: a fully implemented Lisbon would formalise Morocco’s access through the multilateral framework rather than through bilateral arrangement.

OPRC 1990 IMO regional implementation context

The International Convention on Oil Pollution Preparedness, Response and Co-operation 1990 (OPRC) was adopted at IMO on 30 November 1990, just 44 days after the Lisbon Agreement signature. The temporal proximity is not coincidental: both instruments emerged from the same late-1980s consensus on regional and global cooperation in pollution response, with OPRC providing the global framework and Lisbon (with Bonn and Helsinki) providing the regional operational delivery.

OPRC entered force on 13 May 1995, with broad ratification across the maritime states. OPRC requires every party to develop a National Oil Spill Contingency Plan, to require Shipboard Oil Pollution Emergency Plans (SOPEP) for tankers and large ships under MARPOL Annex I Regulation 37, to establish a National Reporting System, and to cooperate with neighbouring states in regional arrangements.

OPRC Article 7 explicitly endorses regional agreements as the preferred operational delivery mechanism. The Lisbon Agreement is intended to be the regional implementation of OPRC for the NE Atlantic Iberian-Moroccan margin, on the same model as Bonn for the North Sea. Each of the four Lisbon state parties is also a party to OPRC: France ratified OPRC in 1993, Spain in 1994, Portugal in 2007 (with delay), and Morocco in 2003. The EU acceded to OPRC as a regional integration organisation in 2002.

The OPRC-HNS Protocol 2000 extends OPRC to Hazardous and Noxious Substances other than oil and was adopted at IMO on 15 March 2000, entering force on 14 June 2007. The four Lisbon state parties have ratified or acceded to OPRC-HNS to varying degrees, and the substantive scope of “harmful substances” in the Lisbon text covers the OPRC-HNS scope by virtue of the broader Lisbon definition.

The Lisbon Agreement’s non-entry-into-force has meant that OPRC’s regional-implementation expectation is not formally satisfied for the NE Atlantic Iberian-Moroccan margin. The IMO has not formally objected because the de facto cooperation (through EMSA, EU instruments and bilateral arrangements) delivers operational equivalence, but the formal symmetry contemplated by OPRC is incomplete.

Relationship to OSPAR Convention 1992

The OSPAR Convention 1992, which entered into force in 1998, is the environmental convention for the wider North-East Atlantic. OSPAR has 16 contracting parties and covers the NE Atlantic from the Arctic to 36° N off the Iberian Peninsula and west to 42° W in the mid-Atlantic, an area substantially overlapping with the Lisbon Agreement polygon.

The intended relationship between Lisbon and OSPAR is complementary, not overlapping, on the same model as the Bonn-OSPAR relationship in the North Sea. Lisbon (when in force) would be operational and response-focused: it would activate when a spill has occurred or is imminent, it would have 24-hour duty officers at each party CNA, and it would command surveillance and equipment movements. OSPAR is preventive and ecosystem-focused: it adopts Programmes and Measures (binding decisions) on offshore oil and gas discharge limits, hazardous substances, eutrophication, biodiversity, marine litter and ocean acidification, and operates on a multi-year strategic cycle rather than a real-time tempo.

OSPAR has operational membership overlap with Lisbon in the cases of France, Spain and Portugal; Morocco is not an OSPAR party. The EU is party to both. The OSPAR membership extends north to include Norway, the UK, Iceland, Sweden, Finland, Denmark, Belgium, the Netherlands, Germany and Ireland, plus Switzerland and Luxembourg as landlocked parties. The southern OSPAR boundary at 36° N runs through Andalusian Spanish waters and at the Strait of Gibraltar, leaving the southern Iberian and Moroccan Atlantic outside OSPAR but inside Lisbon.

Practical coordination between Lisbon (where it operates de facto through EMSA) and OSPAR (where it operates formally) runs through cross-secretariat communication and through national CNA dual-membership arrangements. The relationship would be formalised through joint OSPAR-Lisbon meetings once Lisbon enters force, on the model of the joint OSPAR-Bonn meetings in the north.

Relationship to Bonn Agreement 1983

The Bonn Agreement 1983 is the immediate northern neighbour of the Lisbon Agreement. Bonn’s geographical scope extends south to approximately 48° 30’ N in the Atlantic approaches and west to 5° W in the Channel, with the Lisbon polygon picking up at Cape Finisterre at approximately 42° 53’ N. Between these latitudes is the southern Bay of Biscay which is in neither polygon, covered de facto through French dual-membership in both regimes (when Lisbon enters force) and through the 1995 French-Spanish bilateral.

The two regimes share architectural pattern: state-to-state cooperation, EU as regional party, secretariat function, zones of responsibility, mutual assistance, surveillance, information exchange. The Bonn Information System (BIS) is the operational reference for the equivalent Lisbon arrangement once entered into force.

France is the unique dual-member state, party to both Bonn (since 1983) and Lisbon (signature 1990, ratification 1992). The French dual-membership creates both opportunity and complexity:

• Opportunity: French operational doctrine, technical expertise (CEDRE) and equipment stockpiles serve both regimes, with personnel and equipment moving fluidly across the Bonn-Lisbon boundary at approximately 48° 30’ N
• Complexity: French zones of responsibility under Bonn (Channel, southern North Sea approaches) interact with French zones of responsibility under Lisbon (Bay of Biscay, Aquitaine), requiring careful boundary delineation and dual-regime exercise scheduling

The non-entry-into-force of Lisbon has meant that France’s southern Bay of Biscay response operates outside any formal multilateral regime, instead through national doctrine plus the 1995 French-Spanish bilateral plus EU instruments. This is workable but legally less coherent than a fully entered-into-force Lisbon would deliver.

The Bonn Agreement Manual on Oil Pollution Counter Action is, in practice, the reference doctrine used by the de facto Lisbon-area cooperation. Spanish, Portuguese and Moroccan technical authorities have developed national doctrine substantially patterned on the Bonn Manual, with adjustments for warmer water temperatures (which favour dispersant use), longer fetch and higher swell (which can degrade mechanical recovery), and proximity to high-productivity fishing grounds (which weights ecological caution).

French-Spanish 1995 Bay of Biscay bilateral

The 1995 Bay of Biscay Cooperation Agreement between France and Spain is the principal bilateral instrument operating in the Lisbon polygon since the Agreement’s non-entry-into-force. The bilateral was signed at Bayonne on 30 March 1995 and entered force in 1996, covering the southern Bay of Biscay between approximately 44° N (south of the Bonn polygon) and the Spanish-Portuguese border at the Minho river.

The bilateral addresses:

• Search and rescue coordination between the Préfecture maritime de l’Atlantique at Brest and the Spanish SASEMAR maritime rescue coordination centres at Bilbao and Gijón
• Pollution response cooperation including mutual assistance for booms, skimmers and dispersant aircraft
• Surveillance coordination including aerial sortie deconfliction and information exchange on detected slicks
• Fisheries control coordination (a non-pollution matter but operationally related)
• Police and customs coordination for transboundary maritime crime

The bilateral has been activated multiple times since 1995, notably during the Erika 1999 response (with French lead and Spanish technical support for the southern slick trajectory) and during the Prestige 2002 response (with Spanish lead and French support for the northward slick trajectory). The bilateral filled the gap that the Lisbon Agreement was intended to address but could not because of non-implementation.

The bilateral is less ambitious than the Lisbon Agreement on three dimensions:

• Geographical scope is narrower (southern Bay of Biscay only, not the whole Iberian-Moroccan margin)
• Multilateral cooperation is absent (only France and Spain are parties)
• EU-level support is informal (EMSA is not a contemplated party to the bilateral)

But the bilateral is more agile because the two states can adjust the doctrine and operations through ministerial channels without multi-party negotiation. It has been a workable substitute for the formal Lisbon framework in the southern Bay of Biscay area.

A parallel Spanish-Portuguese bilateral for the Galician-Northern Portuguese coastal margin operates through the Mediterranean and Atlantic Bilateral Cooperation framework, covering search and rescue and pollution response between the A Coruña and Viana do Castelo coastal regions. The bilateral was developed in stages through the 1990s and 2000s, formalised in part through the 2008 Iberian Peninsula Search and Rescue Region arrangement at IMO.

A Spanish-Moroccan bilateral for the Strait of Gibraltar Atlantic approach addresses pollution response cooperation between SASEMAR and the Moroccan Direction de la Marine Marchande, with mutual assistance for the high-traffic Strait approach.

2002 Bay of Biscay PSSA proposal (IMO 2003 rejection)

In 2002, in the immediate aftermath of the Prestige disaster, France, Spain, Portugal, the UK, Ireland and Belgium jointly submitted to IMO a proposal to designate the Bay of Biscay as a Particularly Sensitive Sea Area (PSSA) under the IMO Assembly Resolution A.927(22) then in force (now A.982(24) of 2005). The proposal was tabled at the IMO Marine Environment Protection Committee (MEPC) 49th session in July 2003.

The proposed PSSA boundaries covered the Bay of Biscay from approximately 48° 30’ N (Bonn southern boundary) south to approximately 42° 30’ N (just north of Cape Finisterre) and west to approximately 15° W (open Atlantic). The PSSA case rested on the ecological vulnerability of the Bay of Biscay including its importance for migratory cetaceans (notably the Bay of Biscay common dolphin stock and fin whales), its fisheries productivity, the Galician rias sensitivity, and the demonstrated vulnerability to oil pollution as evidenced by the Erika and Prestige incidents.

The associated protective measures (APMs) proposed included:

• Mandatory ship reporting system for tankers carrying heavy fuel oil
• Mandatory routing with traffic separation away from the most sensitive coast
• Mandatory pilotage in the Cape Finisterre approach
• Recommendations on places of refuge procedures
• Enhanced surveillance in cooperation with EMSA

The IMO MEPC 49 considered the proposal and rejected it in 2003 on technical grounds including objections from major flag states (Liberia, Bahamas, Panama) on freedom of navigation concerns under UNCLOS Article 211 and on the Bay of Biscay size as too large to qualify as a “particularly sensitive” area. The rejection was a major political defeat for the Iberian-French coastal states and a counterpoint to the contemporaneous post-Prestige EU response which delivered through Erika III the substantive measures the PSSA proposal sought.

The 2003 PSSA rejection is sometimes cited in policy literature as evidence that the Iberian-Moroccan margin needs the Lisbon Agreement as a parallel non-IMO regime that can deliver protective cooperation without IMO veto. The Lisbon Agreement’s pending status, however, has not yet enabled this alternative.

A smaller revised PSSA proposal for the Galician coast specifically (rather than the whole Bay of Biscay) has been discussed periodically but has not been resubmitted to IMO. The 2024 Galápagos PSSA expansion proposal at IMO (Ecuador’s submission for the Pacific equatorial coast, distinct from the Iberian context) has been advanced as a model for re-engagement on the Galician PSSA, but no formal Iberian resubmission has occurred as of 2026.

Historical parallel: HNS Convention 30-year ratification gap

The Lisbon Agreement’s 35-year ratification gap is paralleled by the HNS Convention 1996 which took roughly 30 years before entering into force as the HNS Convention 2010 Protocol (still not in force as of 2026 in many jurisdictions). The two cases share several features:

• Multilateral instrument with multiple state-by-state ratification requirements
• Substantive scope that addresses real and serious problem (chemical-spill liability for HNS; regional cooperation for NE Atlantic pollution)
• Implementation gap filled in part by alternative mechanisms (EU regulation in HNS case; EMSA and EU Civil Protection in Lisbon case)
• Industry concerns that have slowed ratification (HNS contributors’ levy in HNS case; financial-contribution scale in Lisbon case)
• Political prioritisation that has been low because of the substitution dynamic

The HNS Convention parallel suggests that multilateral instruments with substantive cooperation scope can persist in pending status for 30 to 40 years when alternative mechanisms deliver operational equivalence. Whether the Lisbon Agreement will eventually enter force, on a similar trajectory to HNS finally clearing its hurdles, depends on Spanish ratification which depends in turn on the resolution of the zones-of-responsibility concerns and the financial-contribution arrangement.

Other multilateral maritime instruments with extended ratification gaps include the Salvage Convention 1989 (entered force 1996, but only after substantial industry engagement), the Bunkers Convention 2001 (entered force 2008 after seven years), the Wreck Removal Convention 2007 (entered force 2015 after eight years), and the 2010 Manila Amendments to STCW (which were achieved through tacit acceptance rather than explicit ratification). The Lisbon Agreement falls at the longer end of this distribution but is not unprecedented.

2024 Spanish parliamentary review status

In 2024, the Comisión de Asuntos Exteriores of the Congreso de los Diputados (Spanish lower chamber) examined the dossier of the Lisbon Agreement ratification at the request of the Ministerio de Asuntos Exteriores, Unión Europea y Cooperación. The review process included:

• Briefings by SASEMAR on operational equivalence delivered by EMSA services
• Briefings by the Galician fishing-industry representatives on the desirability of formal multilateral framework
• Briefings by the Ministerio para la Transición Ecológica on environmental dimensions
• Cross-referencing with the 2024 review of the Lisbon Agreement zones-of-responsibility technical annex by Spanish naval and SASEMAR experts

The 2024 review concluded with a non-binding recommendation to defer ratification pending technical clarification of the zones overlap with the Bonn Agreement 1983 and pending finalisation of a parallel Spanish-Moroccan bilateral on the Strait of Gibraltar approach and Western Sahara Atlantic margin. The recommendation was forwarded to the Council of Ministers for consideration.

The 2024 review reflects continued non-urgency in Madrid policy circles given the EMSA operational equivalence and given competing political priorities (the post-COVID recovery, EU green transition, regional autonomy debates). Whether a future Spanish government will prioritise ratification depends on factors including:

• A major future spill in Galician or Moroccan waters that exposes the EMSA-substitute gaps
• A change in the Spanish-Moroccan diplomatic relationship that closes the Western Sahara concern
• A dedicated political champion within the Spanish coalition who prioritises maritime environmental cooperation
• A diplomatic initiative from Portugal, France, Morocco or the EU that resets the negotiating context

As of 2026, none of these factors has materialised at sufficient strength to prompt ratification.

Operational technique gap-filling: Bonn-style equipment

In the absence of a formally entered-into-force Lisbon Agreement, the operational technique for pollution response in the polygon has been built up by national authorities individually, drawing heavily on the Bonn Agreement Manual on Oil Pollution Counter Action as the de facto reference doctrine.

Spanish equipment stockpile (SASEMAR plus Marina Mercante plus regional government Galician stockpiles) totals approximately 30 km of boom across the Atlantic Spanish coast, with skimmer recovery capacity of approximately 300 m³/h aggregate. The principal stockpile depots are at A Coruña, Vigo, Gijón and Santander, with regional depots at Bilbao and Cádiz. Dispersant aircraft are operated by the Marina Mercante through a contract with Air Tractor-type aerial application platforms and through the EMSA-contracted assets.

Portuguese equipment stockpile (DGAM plus Marinha Portuguesa) totals approximately 15 km of boom, with skimmer recovery capacity of approximately 150 m³/h. The principal stockpile depots are at Lisbon, Sines, Leixões and Faro. Dispersant capacity is provided through DGAM contracts and through EMSA SOSRV access.

French equipment stockpile (Marine Nationale plus Douanes plus Affaires maritimes) is shared with the Bonn-area French stockpile, with approximately 40 km of boom and substantial skimmer capacity available through the dual-regime arrangement. The CEDRE technical institute at Brest provides world-class technical advice and dispersant doctrine.

Moroccan equipment stockpile (Marine Marchande plus Royal Moroccan Navy) totals approximately 8 km of boom, with limited skimmer recovery capacity, supplemented by ONHYM offshore-operator response equipment under contract for upstream operations. Morocco’s stockpile is the smallest among the four state parties and the most reliant on EMSA assistance through the EU-Morocco bilateral.

EMSA SOSRV access for the polygon includes several vessels under contract from bases at Lisbon, Vigo, A Coruña and Algeciras, with 24-hour mobilisation from request to sea-going response and mechanical recovery capacity of approximately 300 to 800 m³/day per vessel.

Dispersant doctrine in the polygon follows the CEDRE approval scheme for France, the SASEMAR approval scheme for Spain, the DGAM approval scheme for Portugal and the Moroccan national scheme. The schemes are loosely harmonised through OPRC technical exchange but not formally aligned through a Lisbon-level instrument. The principal dispersants in operational use are Slickgone NS, Corexit 9500, and the Dasic LT-type formulations, with national variation by stockpile.

Air surveillance runs at perhaps 400 to 600 sorties per year aggregate across the four state parties, considerably less than the Bonn area’s ~2,000 sorties per year. The lower total reflects the smaller polygon traffic relative to North Sea, and the substitution of CleanSeaNet satellite surveillance for some routine flying.

Climate-driven Atlantic storm increase pressure

Climate-driven Atlantic storm increase is a long-term pressure on the polygon’s pollution-response system. Climate research published through the 2020s (IPCC AR6, regional studies by the Spanish Meteorological Agency AEMET, the Portuguese IPMA, and the French Météo-France) projects:

• Increased winter storm intensity in the NE Atlantic, with median wind speeds in the strongest Force 9 plus storms increasing by approximately 5 to 10% by 2050
• Increased storm frequency in the shoulder seasons (autumn and spring) with approximately 15 to 25% more storm-day events
• Sea-level rise of approximately 0.3 to 0.6 m by 2050 along the Iberian-Moroccan coast, with disproportionate impact on low-lying estuarine areas
• Increased wave heights in the open Atlantic by approximately 5 to 10%, with corresponding impact on grounding risk for tankers approaching coastal lanes

The implications for pollution-response capacity are significant. Storm-condition response doctrine (developed by Bonn for the Braer 1993 incident in 70-knot winds) becomes more frequently applicable. Mechanical recovery is degraded above approximately 12 m/s wind and 3 m wave height, conditions that occur more often under climate change. Aerial surveillance is degraded above approximately 20 m/s wind because of safety considerations for aircraft. Dispersant aerial application has tighter operational windows in stormy conditions because of spray-drift uncertainty.

The increased storm pressure has been advanced as a reason for prioritising Lisbon ratification in recent Spanish parliamentary debate. The argument is that a fully implemented multilateral framework with formal mutual assistance, formal zones of responsibility, and formal Secretariat would better support the response capacity required under increasing climate stress than the de facto substitute of bilateral and EMSA arrangements.

The climate pressure also drives operational doctrine adaptation: increased emphasis on pre-position of equipment near climate-vulnerable coasts, increased use of satellite surveillance as an alternative to weather-degraded aerial surveillance, and increased investment in all-weather response vessels (typically Norwegian SOSRV-class designs adapted for Iberian-Moroccan service).

Offshore wind development pressure

Offshore wind development in the Iberian-Moroccan Atlantic is a significant emerging pressure. The principal projects in development as of the mid-2020s are:

• Floating offshore wind projects off the Galician and Asturian coasts in Spain, with several pilot installations and proposed commercial-scale arrays of 300 to 1,000 MW each, leveraging the high-wind regime of the NE Atlantic
• Floating offshore wind projects off the Northern Portuguese coast, principally in deep-water regions where bottom-fixed alternatives are unfeasible
• Floating offshore wind projects off the Atlantic Moroccan coast under the Moroccan 2030 Energy Strategy
• Bottom-fixed offshore wind projects in the southern Bay of Biscay French-Spanish boundary area, building on established North Sea bottom-fixed experience adapted for Atlantic conditions

The combined offshore wind installed capacity in the polygon is projected to reach approximately 5 to 8 GW by 2030 and approximately 25 to 40 GW by 2050, smaller than the North Sea build-out but substantial in absolute terms.

The implications for pollution-response capacity are similar to those already discussed for Bonn:

• Construction-phase risks including vessel collision with installation vessels carrying large bunker fuel quantities
• Operational-phase risks including service vessel bunker spills, transformer-platform transformer-oil leakage, and collision between service vessels and turbine foundations
• Decommissioning-phase risks including large-scale lubricant drainage, nacelle-contained fluid release and foundation-removal sediment disturbance
• Floating-specific risks including mooring-line failure leading to drifting installations, dynamic-cable damage, and inter-array cable damage

The offshore wind pressure has been advanced as another reason for prioritising Lisbon ratification, on the argument that a multilateral framework better supports the cross-boundary risk management that floating wind farms in the Bay of Biscay (with potential drift trajectories crossing Spanish-French maritime boundaries) require. The argument has not yet prevailed in Spanish ratification politics, but it is gaining traction in the 2026 Spanish parliamentary review cycle.

Post-Brexit Atlantic-fishing-fleet refocus

Post-Brexit Atlantic-fishing-fleet refocus is a shaping factor for the polygon’s risk profile. After Brexit on 1 January 2021, the UK left the EU Common Fisheries Policy, with consequent reorganisation of EU fishing access to UK waters and reciprocal UK access to EU waters. The reorganisation has driven:

• Increased Spanish, French and Portuguese fishing effort in the Iberian-Moroccan EEZs and in the EU-Morocco fisheries partnership waters off Western Sahara, partly substituting for lost access to UK waters
• Increased vessel traffic in the polygon associated with the higher fishing effort, with the inevitable corollary of increased grounding risk and discharge risk from fishing vessels (although per-incident scale is smaller than tanker incidents)
• Increased political weight of the Galician, Basque and Portuguese fishing communities within the EU policy debate, with consequent advocacy for stronger pollution-response cooperation in the polygon

The refocus has not directly driven Spanish ratification of the Lisbon Agreement, but it has reinforced the political constituency that benefits from a fully implemented framework. The Galician fishing-industry confrarías have been consistent advocates for ratification, particularly after the Prestige 2002 economic shock, and the post-Brexit refocus has strengthened their political weight by increasing the value of the polygon waters to their livelihoods.

A parallel pressure from the EU-Morocco fisheries partnership (most recently the 2019-2023 Protocol, with renegotiation pending) has reinforced the cross-boundary cooperation imperative. Spanish and Portuguese vessels fishing under the partnership in Moroccan and Western Sahara waters have direct interest in functioning Spain-Morocco pollution-response cooperation, which a fully implemented Lisbon Agreement would deliver more cleanly than the current bilateral arrangements.

Comparison to Abidjan Convention 1981 (parallel African Atlantic)

The Abidjan Convention 1981 is the immediate southern neighbour of the Lisbon Agreement, covering the West African Atlantic margin from the Senegal-Mauritania border at approximately 16° 04’ N (the Lisbon southern boundary) south to Cape Agulhas in South Africa. The Abidjan Convention has 22 contracting parties along the West and Central African Atlantic coast and entered into force in 1984.

The two regimes are intended to be operationally complementary:

• Geographical scope: Lisbon covers the Iberian-Moroccan margin north of 16° 04’ N; Abidjan covers the West and Central African margin south of 16° 04’ N
• Substantive focus: Lisbon (when in force) would be operational and response-focused; Abidjan is broader, covering both pollution and biodiversity, more like OSPAR in the north
• Membership: Lisbon has 4 state parties + EU; Abidjan has 22 state parties (no EU regional party)
• Implementation: Lisbon is non-implemented; Abidjan is implemented but with significantly weaker operational delivery in many parties because of capacity constraints

Cross-boundary cooperation between the two regimes runs through bilateral arrangements between Morocco (Lisbon) and Mauritania (Abidjan), and through the IMO OPRC framework as the global parent. The cross-boundary case is significant because tanker traffic from West Africa (Nigeria, Angola, Equatorial Guinea) routes north through both polygons en route to Iberian and European refineries, and the southern Moroccan / Western Saharan / Mauritanian transit zone is one of the higher-traffic Atlantic corridors.

The Abidjan-Lisbon comparison illustrates the EU regional integration dimension: where Lisbon would benefit from formal EU membership and EMSA support, Abidjan operates without the analogous regional integration body and consequently with weaker operational delivery. The contrast is sometimes cited in policy literature as a reason that even non-implemented Lisbon (with EMSA substitute) delivers better outcomes than implemented Abidjan (without comparable substitute).

Comparison to Barcelona Convention 1976/1995 (parallel Mediterranean)

The Barcelona Convention 1976/1995 governs the Mediterranean environmental protection and pollution response regime, with the Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea (REMPEC) in Malta as the operational arm. Barcelona has 22 contracting parties (the Mediterranean coastal states plus the EU) and is fully implemented.

The Barcelona-Lisbon comparison provides a useful counterfactual: what would Lisbon look like if it had been implemented? REMPEC’s principal activities include:

• Regional Information System (analogous to Bonn BIS) for incident reporting and resource-database management
• Regional Marine Pollution Emergency Response Plan with zones of responsibility and mutual assistance arrangements
• Manual on Oil Pollution broadly modelled on the Bonn Manual
• Air surveillance programme at approximately 200 to 400 sorties per year (smaller than Bonn but comparable to what Lisbon would deliver)
• Joint exercises including major Mediterranean-wide exercises rotating among parties
• Training for Mediterranean CNAs

Barcelona’s Mediterranean membership crosses EU/non-EU boundaries in a way that Lisbon would also: Algeria, Egypt, Israel, Lebanon, Libya, Morocco, Tunisia and Turkey are non-EU Barcelona parties alongside the EU and the EU coastal members. Morocco is consequently a party to both Barcelona and Lisbon (the latter pending), giving Morocco a useful parallel reference for what implemented Lisbon cooperation would deliver.

The Barcelona model has been advanced in policy literature as a direct template for how Lisbon could function if implemented. The argument is that REMPEC’s track record of delivering operational cooperation across diverse political alignments (EU, North African, Levantine) demonstrates the feasibility of comparable Lisbon delivery across France, Spain, Portugal, Morocco and the EU.

EMSA’s role in the implemented Lisbon would broadly parallel REMPEC’s role in Barcelona, with EMSA providing CleanSeaNet, SafeSeaNet and SOSRV support to the Lisbon parties on the same model that REMPEC supports the Barcelona parties (with EMSA covering both regions through its EU-wide mandate). The functional parallel is one of the reasons the Spanish ratification debate has not been more urgent: the EMSA-REMPEC functional similarity gives Madrid policy makers confidence that EMSA delivers operational equivalence even without formal Lisbon ratification.

2030+ outlook: prospects for Spanish ratification

The 2030+ outlook for the Lisbon Agreement entry into force depends on several factors that may or may not align in the late 2020s and 2030s.

Factor 1: Climate-related Atlantic storm increase. As discussed above, the projected increase in storm intensity and frequency strengthens the case for a fully implemented multilateral framework. If a major storm-driven incident occurs in the Galician or Brittany area in the late 2020s, the political shock could prompt Spanish ratification on the post-Prestige model.

Factor 2: Offshore wind development. The accelerating floating-wind build-out in the polygon creates new cross-boundary risk-management requirements that a multilateral framework would handle more cleanly. As wind capacity grows toward the 25-40 GW range by 2050, the framework gap may become more salient.

Factor 3: Post-Brexit Atlantic-fishing-fleet refocus. The increased fishing effort in the polygon increases the political constituency for stronger response cooperation. The Galician confrarías and Basque fishing federations are consistent advocates.

Factor 4: Spanish-Moroccan diplomatic relationship. Resolution of the Western Sahara dispute (or movement toward bilateral accommodation) would close one of the principal Spanish concerns about the Lisbon zones of responsibility. Recent positive movement in the Spanish-Moroccan relationship since approximately 2022 is a constructive factor.

Factor 5: EU regulatory pressure. If the EU were to formally encourage Spanish ratification through Council resolution or through the European Commission’s annual maritime safety reports, the political weight in Madrid would increase.

Factor 6: A specific ratification champion. A dedicated political or institutional advocate who prioritises ratification within the Spanish coalition could break the long-running inertia. Past Spanish foreign ministers have shown sporadic interest but not sustained prioritisation.

Factor 7: Generational change. The negotiators and senior officials who navigated the 1990 signature and the 1990s ratification debates have largely retired. A new generation of officials, less invested in the original concerns, may approach the dossier more pragmatically.

The most likely scenario as of 2026 is continued non-implementation through the late 2020s, with EMSA operational equivalence covering the operational gap, and possible ratification in the 2030 to 2035 window if one or more of the seven factors above align. A pessimistic scenario sees continued non-implementation indefinitely, with the Agreement persisting as a formally pending instrument that is operationally substituted by EU and bilateral arrangements. An optimistic scenario sees ratification in the 2027-2030 window driven by a combination of climate pressure, offshore-wind cooperation requirements and a strong Spanish-Moroccan reset.

The 2024 Galápagos PSSA expansion at IMO (Ecuador’s submission for the Pacific equatorial coast) is sometimes cited as a parallel example of how IMO-level instruments can be revisited after long periods. The Galápagos case is substantively different from the Lisbon case (a PSSA proposal versus a regional cooperation agreement), but it illustrates that multilateral instruments can re-emerge in policy attention after years of dormancy.

Formula, assumptions, and limits

Formula

The Lisbon Agreement’s substantive operational machinery, when entered into force, would parallel the Bonn machinery. The principal formal expression is the status indicator for the Agreement itself:

The ratification gap is:

The signatories count is:

The geographical scope is:

The principal incident-volume references are:

Derivation

The Agreement’s status formula derives from the multilateral treaty entry-into-force requirement of unanimous ratification by all signatories, expressed in Article 22 of the Agreement text. The non-entry-into-force status is the simple consequence of Spain’s pending ratification: with one of five signatories outstanding, the Agreement remains in pre-entry-into-force status pursuant to its own terms.

The ratification gap of 36 years derives from the period between signature on 17 October 1990 and the present analysis date in 2026. The gap is exact arithmetic, not an approximation.

The signatories count of 5 derives from the diplomatic conference at Lisbon on 17 October 1990 and the subsequent EU adhesion through Council Decision 1993, totalling four state signatories (France, Morocco, Portugal, Spain) plus the EU as a regional integration organisation party.

The incident volumes derive from the official post-incident reports: ITOPF, EMSA, Spanish Ministry of Environment, French CEDRE, and the Prestige Inquiry by the Spanish state. The volumes are documented within ranges; the central estimates above are the most commonly cited consensus figures.

Assumptions

The status assessment assumes that Spanish ratification has not occurred as of the analysis date. If Spanish ratification were lodged with the depositary at any point, the Agreement would enter into force after the depositary’s notification process (typically within 60 to 90 days of the final ratification deposit), and the status formula would update accordingly.

The signatory count assumes that no additional state has acceded to the Agreement since 1990. The Agreement text contemplates accession by other coastal states with relevant interests (for example Mauritania could potentially accede for the southern boundary), but no such accession has occurred.

The geographical scope assumes the polygon as defined in Article 2, with Cape Finisterre as the northern terminus and the Senegal-Mauritania border as the southern terminus. The polygon is uncontested in principle although the precise boundary at the Spanish-Moroccan Strait of Gibraltar Atlantic and at the Western Sahara stretch carries political-legal complexity.

Worked example

Consider a hypothetical major spill scenario: a 150,000 dwt tanker grounds off the Galician coast at approximately 43° 10’ N, 9° 18’ W (north-west of Cape Finisterre) during a storm with Force 9 westerly winds, releasing approximately 40,000 tonnes of heavy fuel oil. Under a fully implemented Lisbon Agreement, the following would occur:

• T+0 minutes: Initial detection by Galician coastal observation and coastguard radar
• T+15 minutes: POLREP Part I transmitted via the Lisbon Information System to all parties, with copies to EMSA Secretariat
• T+30 minutes: EMSA CleanSeaNet alert (if next satellite pass within window) cross-references the slick
• T+1 hour: SASEMAR declares Tier 3 response based on volume, sensitivity (Galician rias) and trajectory (eastward toward shore)
• T+2 hours: Article 6 mutual assistance requests issued to France (CEDRE technical advice + dispersant aircraft), Portugal (boom and skimmer support), Morocco (response vessel access if relevant), and EMSA (SOSRV deployment + Maritime Support Services)
• T+8 hours: First international equipment in transit (French CEDRE technical team and dispersant aircraft from Brest; Portuguese boom and skimmer from Leixões)
• T+14 hours: First dispersant sortie airborne (subject to weather window)
• T+24 hours: First EMSA SOSRV on scene (mobilised from Lisbon or Vigo base)
• T+48 hours: Full international response mobilised; lead state SASEMAR coordinating multi-party operations

Estimated total committed assistance under Article 6 across the parties: approximately 35 km of boom, 4 dispersant aircraft, 3 SOSRVs, 2 recovery vessels, 60 personnel technical and operational. Estimated total response cost over the first 30 days: approximately €60 million, of which approximately €40 million at-sea response, €15 million shoreline response, €5 million administrative and legal. Recovery from the CLC 1992 insurer is pursued by the lead state through the polluter’s P&I Club at the CLC bunker limit (approximately SDR 89.77 million for a 50,000 GT vessel as of 2026 limits).

In the actual non-implemented Lisbon scenario, the same response would occur in practice but through the EMSA / EU Civil Protection / bilateral Spain-France-Portugal channels rather than under Lisbon governance. The substantive outcome is similar; the legal-administrative architecture is different.

Edge cases and limits

The Lisbon Agreement’s edge cases include:

• Cross-boundary incidents at the Spanish-French Bay of Biscay boundary at approximately 44° N (between the Bonn polygon’s southern boundary at 48° 30’ N and the Lisbon polygon’s northern boundary at Cape Finisterre at 42° 53’ N), handled through dual French membership (when Lisbon enters force) and the 1995 French-Spanish bilateral
• Cross-boundary incidents at the Spanish-Moroccan Strait of Gibraltar Atlantic approach, handled through bilateral arrangements pending Lisbon implementation
• Cross-boundary incidents at the Moroccan-Mauritanian boundary at the Western Sahara terminus, handled through bilateral arrangements with Mauritania (an Abidjan Convention party, not a Lisbon party)
• Deep-Atlantic tanker casualties (such as Prestige’s sinking at 3,500 m depth), where the deep-water spill plume behaviour differs significantly from coastal-grounding scenarios and requires specialised technical doctrine
• HNS-only chemical incidents where the oil-doctrine reference (Bonn Manual) requires HNS-specific overlay
• Politically sensitive offshore zones including the Western Sahara waters where Spain does not recognise Moroccan sovereignty

The Agreement’s limits include:

• It is a state-to-state instrument and does not directly bind private operators
• It is regionally limited and does not apply outside the defined polygon
• It relies on voluntary cooperation and would not oblige any party to over-commit at the expense of its own national emergency
• It does not address liability and compensation which run through the parallel CLC, Bunkers and HNS regimes
• It does not directly address places of refuge for stricken vessels, the operational gap exposed by Prestige and addressed at EU level by Erika III rather than at Lisbon level

Regulatory basis

The regulatory basis for the Lisbon Agreement is the multilateral treaty signed at Lisbon on 17 October 1990 with depositary functions performed by the Government of Portugal, the OPRC 1990 Convention as the global parent (adopted at IMO 30 November 1990, in force 13 May 1995), the OPRC-HNS Protocol 2000 as the HNS extension, the OSPAR Convention 1992 as the environmental complement for the wider NE Atlantic, the Bonn Agreement 1983 as the architectural template, the Barcelona Convention 1976/1995 as the parallel Mediterranean regime, the Abidjan Convention 1981 as the parallel southern African Atlantic regime, and the Hamburg SAR Convention 1979 with the IAMSAR Manual as the SAR interface.

National implementation legislation in each prospective party (Spain Ley 21/2003 on Aviation Safety and adjacent maritime safety legislation; Portugal Decree-Law 13/2008 on maritime pollution response; France Code de l’environnement Article L218; Morocco Dahir on maritime safety) provides the domestic legal basis for CNA operations. EU implementation runs through the Erika I, II and III packages and through the EMSA founding Regulation (EC) 1406/2002 as amended.

Common errors

Five errors recur in commercial and academic discussion of the Lisbon Agreement. First, treating the Lisbon Agreement as operational when it is in fact not in force; the Agreement has been pending entry into force for 35 years and the operational machinery contemplated by the text has never been formally activated. Second, conflating the Lisbon Agreement with the OSPAR Convention 1992; the two are distinct instruments with different scope, different membership and different operational focus, although both cover NE Atlantic waters. Third, assuming EMSA is the Lisbon Agreement Secretariat in a formal sense; EMSA delivers operational equivalence but cannot formally hold Secretariat functions until the Agreement enters force. Fourth, equating the 1995 French-Spanish bilateral with the Lisbon Agreement; the bilateral covers a specific subset of the polygon and is a stand-alone instrument independent of Lisbon. Fifth, treating Spanish ratification as imminent based on parliamentary review activity; the 2024 review concluded with a recommendation to defer rather than to ratify, and there is no formal indication that Spanish ratification will occur in the immediate term.

See also

• Bonn Agreement 1983
• OSPAR Convention 1992
• Helsinki Convention 1992
• OPRC 1990 and HNS Protocol
• Barcelona Convention 1976/1995
• Abidjan Convention 1981
• MARPOL Convention
• MARPOL Annex I
• London Convention 1972 and 1996 Protocol
• CLC 1992 Civil Liability for Oil Pollution Damage
• HNS Convention 2010
• Madrid Protocol 1991
• Antarctic Treaty 1959
• Calculator catalogue

References

References for this article include the Cooperation Agreement for the Protection of the Coasts and Waters of the North-East Atlantic against Pollution signed at Lisbon on 17 October 1990 with the Government of Portugal as depositary, the Council Decision 93/550/EEC of 20 October 1993 by which the European Communities approved conclusion of the Agreement (published in the EUR-Lex archive), the IMO OPRC 1990 Convention adopted 30 November 1990 with entry into force 13 May 1995 and the OPRC-HNS Protocol 2000 with 2010 amendments as the global framework, the Bonn Agreement 1983 as the architectural template and reference for operational doctrine including the Manual on Oil Pollution Counter Action and the Aerial Operations Plan 2019 revision, the OSPAR Convention 1992 as the complementary environmental framework, the Helsinki Convention 1992 as the Baltic counterpart, the Barcelona Convention 1976/1995 as the parallel Mediterranean regime with REMPEC as operational arm, the Abidjan Convention 1981 as the parallel West African Atlantic regime, the EMSA founding Regulation (EC) 1406/2002 as amended and the post-Prestige Maritime Safety Package III (Erika III) of 2009 covering eight legislative instruments including Directives 2009/15, 2009/16, 2009/17, 2009/18, 2009/20, 2009/21 and Regulations 391/2009 and 392/2009, the EMSA CleanSeaNet service description and annual reports, the EMSA SafeSeaNet vessel monitoring system documentation, the technical publications of CEDRE in Brest, the Spanish SASEMAR annual reports, the Portuguese DGAM publications, the Moroccan Direction de la Marine Marchande documentation, the ITOPF technical case studies notably for the Aragon 1989, Erika 1999 and Prestige 2002 incidents, the Spanish Prestige Inquiry reports, the CLC 1992 and Bunkers Convention 2001 liability frameworks, the HNS Convention 2010 liability and compensation regime, the 1995 French-Spanish Bay of Biscay bilateral cooperation agreement, the 2002 Bay of Biscay PSSA submission to IMO MEPC 49 and the 2003 IMO decision, the 2024 Spanish parliamentary review by the Comisión de Asuntos Exteriores of the Congreso de los Diputados, and the Boletín Oficial del Estado parliamentary record. Full citation links appear in the frontmatter.

Related calculators

• IMO OPRC 1990 - Oil Pollution Preparedness Response
• UN1990 - Benzaldehyde (Class 9)
• MARPOL Annex I/37 - Shipboard Oil Pollution Emergency Plan
• IMO Intervention 1969 - Oil Pollution Intervention
• IMO CLC - Civil Liability for Oil Pollution
• IMO Bunkers 2001 - Bunker Oil Pollution Liability
• CLC - Oil Pollution Compensation Limit
• UN1288 - Shale oil (Class 3)

Related formulas

• IMO OPRC 1990 - Oil Pollution Preparedness Response
• UN1990 - Benzaldehyde (Class 9)
• MARPOL Annex I/37 - Shipboard Oil Pollution Emergency Plan
• IMO Intervention 1969 - Oil Pollution Intervention
• IMO CLC - Civil Liability for Oil Pollution
• IMO Bunkers 2001 - Bunker Oil Pollution Liability
• CLC - Oil Pollution Compensation Limit
• UN1288 - Shale oil (Class 3)