Posidonia oceanica meadows (Balearics, Mediterranean)
- Researchers Telesca et al. (2015): 34% regression over the last 50 years, attributed to the cumulative effects of multiple local stressors. Scientific Reports (via Ifremer Archimer)
- Researchers Boudouresque et al. (2021): The decline could be less extensive and less general than claimed. Water (via GIS Posidonie)
- Researchers Provence and Côte d'Azur data, 0–15 m depth: Since 1922, 86% of meadow unchanged, 13% regressed, 1% progressed.
- Researchers Telesca et al. (2015): Known area 1,224,707 ha (about 12,250 km²); data missing for 21,471 km of coastline. Scientific Reports (via Ifremer Archimer)
- Researchers Campagne et al. (2015): Uses 3.5 million ha, citing Laffoley and Grimsditch (2009). Marine Pollution Bulletin (via medtrix.fr)
- Press and investigations Spanish press (2018): Cited about 50,000 km². eldiario.es
- Researchers Arnaud-Haond et al. (2012): Clones are hundreds to thousands of years old; a Formentera clone shared by sites 15 km apart implies a minimum age of 80,000–200,000 years if spread was by clonal growth alone at 4–6 cm a year, a scenario the authors call unlikely. PLoS ONE
- Researchers CSIC and University of Western Australia press releases: Framed the finding as a clone about 100,000 years old and the oldest living organism.
- Company or project Red Eléctrica: 2 ha replanted in the Bay of Pollença for about €500,000; survival above 90% (company evaluation). Red Eléctrica
- Researchers Boudouresque et al. (2021): None of the seagrass restoration programmes in Europe in the 2000s was successful; the largest Posidonia replantings listed were 500 m² and 1,020 m², while natural recolonisation near Marseille ran at 1,250 m² a year. Water (via GIS Posidonie)
Posidonia oceanica, a seagrass found only in the Mediterranean, has been reported to have declined by 34% in 50 years, a figure other researchers dispute. The Balearic Islands banned anchoring over meadows in 2018; boats were still being detected over them in 2025, and carbon-credit and restoration schemes have produced claims that the record does not yet confirm.
About 1 in 270 (0.37%) as reported by Ibiza & Formentera Preservation. In 2018 the Balearic government reported 42 formal reports for 5,269 boats detected over Posidonia.
Status As of October 2026: the Balearic anchoring ban has been in force since 2018; the French first-instance fine on the yacht Laurie I is appealable; no sale of Posidonia carbon credits was found.
- Posidonia oceanica meadows — 34% regression over the last 50 years reported by Telesca et al. 2015, a figure disputed by Boudouresque et al. 2021; causes named include trawling, coastal development, sewage and pollution, anchoring, fish farms and invasive species. Scientific Reports (via Ifremer Archimer)
What happened
Posidonia oceanica is a seagrass found only in the Mediterranean, from a few dozen centimetres to 30–40 m deep. Telesca et al. (2015) gave a known area of 1,224,707 ha (about 12,250 km²), with data missing for 21,471 km of coastline; older estimates are larger. The same study reported a 34% regression over the last 50 years, attributed to the cumulative effects of multiple local stressors. Boudouresque et al. (2021) said the decline could be less extensive and less general than claimed. In Provence and the Côte d'Azur, at 0–15 m depth, 86% of the meadow was unchanged since 1922, 13% had regressed and 1% had progressed.
Under the EU Habitats Directive, Posidonia beds are a priority habitat. The Balearic Islands approved Decree 25/2018 on 27 July 2018, banning trawling, aggregate extraction, dumping of dredged material and uncontrolled anchoring over meadows, and banning removal of dead Posidonia on natural beaches except for traditional manual uses. Fines range from €100 to €2 million; officials said the top fines were meant for oil-spill-scale damage. In 2018 the Balearic government carried out 50,467 actions and 30,326 anchoring checks, detected 5,269 boats over Posidonia and drew up 42 formal reports. In 2025 in Ibiza and Formentera alone, 4,813 boats were detected over Posidonia and 18 formal reports were drawn up (15 in Ibiza, 3 in Formentera).
In France, a Marseille maritime court imposed a €90,000 fine and a three-year ban from French waters on the 37 m Maltese-flagged yacht Laurie I, which anchored over meadow in the Cap Corse–Agriate marine park in July 2025; the ruling was at first instance and can be appealed. In that park, superyacht anchoring on Posidonia fell from 35% in 2019 to 6% in 2025; for boats under 24 m the 2025 figure was 15%.
Money and the meadows: machines removed 39,343 m³ (27,583.5 t) of sand together with dead leaves from 19 Balearic beaches in 2010–2018 (Roig-Munar et al. 2019). In France, a Label Bas-Carbone method for Posidonia protection (Prométhée-Med) was approved in 2023, with a claimed potential of 700,000 t over 30 years on 80,000 ha; no labelled project, volume or price was found. The Andalusian blue-carbon standard (January 2022) and Italy's LIFE SeaForest project (estimating over 5,365 tCO₂ avoided over 10 years) also published no prices or buyers. Formentera's Save Posidonia project, launched in 2017, sells sponsorship from €1 per m² and reported over 250,000 m² sponsored by September 2021. Studies value the meadows at about €280 to €1.7 million per hectare per year, depending on method.
Restoration: Red Eléctrica planted 2 ha in the Bay of Pollença, Mallorca (2018–2020), with 12,800 fragments, for about €500,000, and reported survival above 90% in its own evaluation. Boudouresque et al. (2021) listed the largest replantings as 500 m² (Monaco) and 1,020 m² (Piombino), noted that a WWII bomb crater near Marseille was recolonised naturally at 1,250 m² a year, and quoted the finding that none of the seagrass restoration programmes developed in Europe in the 2000s was successful.
- 1922Baseline year for the Provence and Côte d'Azur comparison (86% of meadow unchanged since)
- 2017Formentera launches Save Posidonia sponsorship
- 2018Balearic Decree 25/2018 approved (27 July); 5,269 boats detected over meadow, 42 formal reports; Red Eléctrica planting begins
- 2019Superyacht anchoring on Posidonia in the Cap Corse–Agriate park: 35%
- 2020Red Eléctrica reports planting survival above 90% (November)
- 2021Boudouresque et al. review of replantings; Save Posidonia reports over 250,000 m² sponsored (September)
- 2022Andalusian blue-carbon standard launched (January)
- 2023French Label Bas-Carbone method for Posidonia approved (April)
- 2025Yacht Laurie I anchors over meadow (July); 4,813 boats detected over meadow in Ibiza and Formentera; superyacht anchoring share 6%
- 2026Marseille maritime court fine reported (August), appealable
What was said
“cumulative effects of multiple local stressors”
“could be less extensive and less general than claimed”
“hundreds to thousands of years old”
“unlikely”
“None of the seagrass restoration programs developed in Europe during the 2000s was successful”
“created a carbon market”
Where accounts differ
Each party's account, side by side, with its source. The record does not settle these points; it shows them.
34% regression over the last 50 years, attributed to the cumulative effects of multiple local stressors.
Scientific Reports (via Ifremer Archimer)The decline could be less extensive and less general than claimed.
Water (via GIS Posidonie)Since 1922, 86% of meadow unchanged, 13% regressed, 1% progressed.
Known area 1,224,707 ha (about 12,250 km²); data missing for 21,471 km of coastline.
Scientific Reports (via Ifremer Archimer)Uses 3.5 million ha, citing Laffoley and Grimsditch (2009).
Marine Pollution Bulletin (via medtrix.fr)Clones are hundreds to thousands of years old; a Formentera clone shared by sites 15 km apart implies a minimum age of 80,000–200,000 years if spread was by clonal growth alone at 4–6 cm a year, a scenario the authors call unlikely.
PLoS ONEFramed the finding as a clone about 100,000 years old and the oldest living organism.
2 ha replanted in the Bay of Pollença for about €500,000; survival above 90% (company evaluation).
Red EléctricaNone of the seagrass restoration programmes in Europe in the 2000s was successful; the largest Posidonia replantings listed were 500 m² and 1,020 m², while natural recolonisation near Marseille ran at 1,250 m² a year.
Water (via GIS Posidonie)5,269 boats detected over Posidonia; 42 formal reports.
Nou Diàri (Ibiza)4,813 boats detected over Posidonia in Ibiza and Formentera; 18 formal reports (15 in Ibiza, 3 in Formentera), about 1 in 270.
Mallorca Magazin€283–513 per hectare per year (€25.3–45.9 million a year in total); only 7 of 25 identified services valued; dead-leaf banquettes valued at €0.
Marine Pollution Bulletin (via medtrix.fr)€172 per m² per year, or €1.72 million per hectare, by an emergy method at Bergeggi.
Marine Pollution Bulletin (via medtrix.fr)€21.2 million a year for 65,000 ha; coastal protection €12.4 million (€191.7 per hectare).
Última HoraHow it looked
Shown
- A Posidonia clone about 100,000 years old, the “oldest living organism”.CSIC and University of Western Australia press releases
- Planted Posidonia with survival above 90%.Red Eléctrica · Red Eléctrica
- Over 250,000 m² of meadow “sponsored”.Consell de Formentera, Save Posidonia project · Spain.info social newsroom
- A carbon-credit method for Posidonia protection with a potential of 700,000 t over 30 years.EcoAct (Atos/Eviden), Digital Realty (Interxion), Schneider Electric and the Calanques National Park · Atos
Recorded
- Telesca et al.: 34% regression of Posidonia over the last 50 years; Boudouresque et al.: the decline could be less extensive than claimed.
- Balearics 2018: 5,269 boats detected over Posidonia, 42 formal reports.
- Ibiza and Formentera 2025: 4,813 boats detected over Posidonia, 18 formal reports.
- Cap Corse–Agriate marine park: superyacht anchoring on Posidonia fell from 35% (2019) to 6% (2025).
- Machine removal of dead Posidonia took 27,583.5 t of sand from 19 Balearic beaches in 2010–2018.
- Sardinia regional funding for 2020–22 was €1.8 million, paying only for temporary relocation of banquettes, not landfill; at least half of the 72 coastal municipalities remove banquettes, tens of thousands of m³ per season.
- Italy's ISPRA: banquettes hold about 93 kg of sediment per m³; removal on one Sardinian site would lose over 1,700 m³ of sediment.
- Campagne et al. valued only 7 of 25 identified services and gave dead-leaf banquettes a value of €0.
Who gained
Reached nature or the ground
Gained elsewhere
Responses on record
- balearic-government (July 2018): Officials said the top fines under Decree 25/2018 (up to €2 million) are meant for oil-spill-scale damage. · eldiario.es
- red-electrica (November 2020): Reported survival of planted Posidonia above 90% in its Marine Forest project in the Bay of Pollença (company evaluation, with IMEDEA as partner). · Red Eléctrica
- consell-de-formentera (September 2021): Reported over 250,000 m² of meadow sponsored through Save Posidonia. · Spain.info social newsroom
- ecoact (April 2023): With Digital Realty, Schneider Electric and the Calanques National Park, announced approval of a Posidonia protection method with a claimed potential of about 24,000 tCO₂e a year. · Atos
In court and with insurers
Lawsuits and rulings
- Claimant won€90bn FineYacht Laurie I anchoring over Posidonia, Cap Corse–Agriate marine parkMarseille maritime court (first instance) · Regulatory · → Yacht Laurie I (37 m, Maltese flag)
The yacht anchored over Posidonia in July 2025. The court imposed a €90,000 fine and a three-year ban from French waters; the ruling is at first instance and can be appealed. Reported in August 2026. SuperYacht24
Insurers
What nature saw
Nature's report opens this page. Below: further outcomes measured on the ground.
What we don't know
Nature
- Not measured Harm to nature: The record holds no measurement of harm to nature.
- Disputed How much has Posidonia declined?
- Disputed How large is the meadow area?
- Disputed How old is the Formentera Posidonia clone?
- Disputed Is seagrass restoration working?
Accounts
Record
- None on record The meadow's total area is not settled: the known area is about 12,250 km² with coastline data missing; Campagne 2015 uses 3.5 million ha and Spanish press in 2018 cited about 50,000 km².
- Disputed The extent of the decline is disputed (34% in 50 years against a review saying it could be less extensive and less general).
- Disputed The age of Formentera clones is disputed: 80,000–200,000 years assumes spread by clonal growth alone, which the authors call unlikely.
- None on record No labelled project, volume or price was found for the French Posidonia carbon method, and no prices or buyers were published for the Andalusian standard or LIFE SeaForest.
- None on record The official Save Posidonia site showed a live counter reading 0 and no total raised at the time of research.
- Insufficient Reported but not verified in the primary text: IUCN lists the species as Least Concern with a decreasing trend (assessed 15 July 2013), and the European Red List of Habitats rates Posidonia beds Vulnerable.
- Insufficient Reported but not verified in the primary text: 529 Natura 2000 sites are designated for Posidonia beds.
- Insufficient Reported but not verified (page would not load): Balearic government 2025 figures of 181,468 actions, 156,043 anchoring checks, 10,062 boats relocated, 6.4% of anchorings on Posidonia and 48 formal reports.
- Insufficient Reported but not verified: Sardinia in 2004 removed leaves from 44 of 116 beaches (106,180 m³), with 80% dumped in unauthorised areas.
- Insufficient Reported but not verified: Posidonia restoration costs of €100,000–500,000 per hectare (2021 analysis cited in a 2025 paper) and a median seagrass survival of 38% across restoration projects (Bayraktarov et al.).
- Insufficient Reported but not verified: an Italian national benefit-transfer estimate of €21,660 per hectare per year (conference presentation, not peer-reviewed).
- Insufficient Reported but not verified: the Andalusian standard still lacked national approval in April 2025 (Carbon Pulse).
Did the harm stop?
Anchoring over meadows continued after the 2018 Balearic ban: 4,813 boats were detected over Posidonia in Ibiza and Formentera in 2025. In the Cap Corse–Agriate park, the superyacht share fell from 35% (2019) to 6% (2025).
Who paid?
Sources
Company or project
Government and regulators
- Multan a 42 de los 5.269 barcos con fondeos sobre posidonia detectados por el Govern balearNou Diàri (Ibiza) · 2018
- Comunicato stampa: spiaggia ecologica (Posidonia banquettes)ISPRA · 2020-06
- Formentera reinforces its sustainable credentials with the 4th Save Posidonia Forum 2021Spain.info social newsroom · 2021-09
Press and investigations
- Baleares: praderas de posidonia (Decree 25/2018 article)eldiario.es · 2018-07-27
- Posidonia anchoring in Ibiza and Formentera (figures from Ibiza & Formentera Preservation)Mallorca Magazin · 2026-08-21
- L'ancora sulla Posidonia: 90mila euro di multa e 3 anni di stop in FranciaSuperYacht24 · 2026-08-17
Communities and civil society
Researchers
- Telesca et al. (2015), Scientific Reports 5:12505: Posidonia oceanica area and regressionScientific Reports (via Ifremer Archimer) · 2015
- Campagne et al. (2015), Marine Pollution Bulletin 97: economic value of Posidonia ecosystem services (France)Marine Pollution Bulletin (via medtrix.fr) · 2015
- Boudouresque et al. (2021): Posidonia replantings, code and decision treeWater (via GIS Posidonie) · 2021
- Roig-Munar et al. (2019), Revista de la Sociedad Geológica de España 32(2): banquette removal on Balearic beachesUniversitat de les Illes Balears research portal · 2019
Connected cases
- African Parks Odzala-Kokoua abuses (Republic of Congo) Republic of Congo · 2010–2025
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Funder (€6m for 2018–2023; 46% of the park budget in 2020)
- EU bans offset-based neutrality claims from 27 September 2026 European Union · 2024–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: adopted the directive
- EU court rejects Austria's challenge to green label for gas and nuclear European Union · 2022–2025
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: set the taxonomy rules
- EU Deforestation Regulation delays and trade pressure European Union · 2022
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Regulator
- EU mirror measure on antimicrobials and Brazil beef exclusion Brazil · 2019–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Regulator that adopted the measure and decided the list
- EU narrows supply-chain law and delays deforestation rule twice European Union · 2024–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Adopted the narrowed directive and postponed the EUDR
- EU seal-product ban's Inuit exemption found ineffective Canada · 2014
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Seal-product ban with an Inuit exemption
- Jadar lithium project Serbia · 2022–2025
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Defendant in the strategic-status case (European Commission)
- Kenyan forest guards shoot dead Sengwer herder Robert Kirotich during evictions Kenya · 2018–2024
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: donor; suspended support for the WaTER programme
- Kenyan water-tower forest evictions followed a 2018 killing by forest guards Kenya · 2016–2024
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: funder of the WaTER programme
- Livelihoods Fund mangrove project (Senegal) Senegal · 2009–2026
- Schneider Electric (Company) — here: Co-developer of the French Posidonia carbon method; there: Corporate investor / credit recipient
- Messok Dja ecoguard abuses (Republic of Congo) Republic of Congo · 2008–2020
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Funder; suspended about €1 million in 2020
- Morocco says it cut cadmium in phosphate fertilisers; EU cannot verify the claim Morocco · 2025
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: acknowledges it cannot verify Morocco's claim
- Nonylphenol ethoxylates: Swiss ban and EU restriction Switzerland · 1984–2014
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Adopted Directive 2003/53/EC
- Plastic waste imports into Türkiye (Adana) Türkiye · 2016–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Assessed Türkiye under Article 45(5) of the Waste Shipment Regulation
- Prestige Spain · 2002–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Provided more than €275m in aid
- Sengwer evictions from Embobut forest and the EU Water Towers programme (Kenya) Kenya · 2014–2024
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Funder of the WaTER programme
- Trade rules curb green industrial policy; WTO rules against Indonesia nickel ban Global · 2013–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Complainant in the Indonesia nickel case; respondent in the palm oil and CBAM disputes
- Uzbek cotton boycott ends forced labour Uzbekistan · 2017–2026
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Trade partner (trade preference)
- World Bank and development bank accountability mechanisms: Embobut (Sengwer), Tata Mundra, Arun III, Jale, Cambodia Kenya · 2007–2024
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Funder of the WaTER programme
- WTO panel backs EU on palm biofuel rules in Malaysia case Global · 2025
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Respondent; set the renewable-status rules
- WTO panel found Indonesia's raw nickel export ban breached rules Indonesia · 2020–2022
- European Union (International organisation) — here: Habitats Directive: Posidonia beds are a priority habitat; there: Brought the complaint at the WTO