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Mar Menor environmental conflict, Spain


The “Mar Menor” is an inland lagoon situated at the south of Spain in Campo de Cartagena within the region of Murcia. Its 135 km2 extension and a depth of 6 meters make it one of the largest salt lagoons in Europe. The lagoon, separated from the Mediterranean sea by a narrow land strip of 22 kilometers long and between 100 and 800 width, has a rich and diverse ecosystem as well as  important cultural values. The “Mar Menor” and its peripheral humid areas count with different figures of protection such as Ramsar convention or the Barcelona convention for the protection of the Mediterranean Sea. Moreover, bordering the lagoon there are two protected natural spaces under the figure of Regional Park: “Arenales y Salinas de San Pedro” and “Calbalanque, Monte de las Cenizas y Peña del Águila”. Despite all of these protections the lagoon faces a serious environmental crisis. From the 1960s onwards the area has been subjected to a progressive process of touristification and urbanization that have risen exponentially the demographic and environmental pressure over his ecosystems. Several engineering projects have been taken place. In 1970 a sports port was built-up and was the starting point of a set of physical changes that will affect the lagoon and its surroundings. In 1973 another project was developed in order to dredge Estacio canal which connected the lake with the Mediterranean Sea. The intention was to allow boats of deeper draft to cross to the lagoon and the result was a great environmental impact due to the alteration of the temperature and salinity of the water, and therefore the ecosystems equilibrium. In 1979, one of the largest engineering works in Spain culminated: the Tajo-Segura transfer. The transfer of water from one river to another was made with the aim of converting the traditional dryland agriculture into irrigated, thus becoming this area in the so-called orchard of Europe although its strong rainfed nature.

 Irrigation agriculture has been growing exponentially since then, sometimes illegally, having different perjudicial effects for lake ecosystems sustainability. On the one hand, one of his most perjudicial effects have been the construction of wells of which many do not comply with the regulations or are totally illegal. This practice has end in the overexploitation of the aquifers and the contamination of its water by nitrates. On the other hand, as the water from some aquifers is salty because its connection with the lagoon a desalination process is required in order to make it useful for agriculture. Therefore, since the 90s private desalination plants proliferated in the area with the authorization of the corresponding public organism (Hydrographic Confederation of Segura). Also an incomplete canalization system was created to conduct the resulting spill, which has a high concentration of salt and nitrates, and prevent it to end in the lagoon. Nevertheless, in practice it did not work and the lagoon faced (and faces) an important amount of spills. This caused an eutrophication episode in 2016 that was repeated in 2019 with even more negative effects due to the extra nitrates dragged by torrential rains. The result: the water of the lagoon became green, the 80% of sea meadow grass disappeared as well as other animals and plants species due to the lack of oxygen. 

All of this factors, together with a scenario of impunity, lack of political involvement, and absent of compliance with the environmental legislation have led to the current ecological crisis. It has to be pointed out that different associations and collectives, such as “Pacto por el Mar Menor”, “Ecologistas en Acción” or “ANSE”, together with some researchers of the University of Alicante and Murcia, are reporting the situation and making efforts to recover the ecosystem as well as to enforce the law and prosecute environmental crimes. The complaints have also reached the European commission.

Basic Data

Name of conflict:Mar Menor environmental conflict, Spain
State or province:Murcia
Location of conflict:Murcia
Accuracy of locationHIGH (Local level)

Source of Conflict

Type of conflict. 1st level:Waste Management
Type of conflict. 2nd level:Building materials extraction (quarries, sand, gravel)
Intensive food production (monoculture and livestock)
Water access rights and entitlements
Dams and water distribution conflicts
Water treatment and access to sanitation (access to sewage)
Transport infrastructure networks (roads, railways, hydroways, canals and pipelines)
Pollution related to transport (spills, dust, emissions)
Urban development conflicts
Tourism facilities (ski resorts, hotels, marinas)
Wetlands and coastal zone management
Specific commodities:Biological resources
Tourism services

Project Details and Actors

Project details

• It is estimated that the reduction of groundwater in the area's aquifers due to overexploitation is approximately about 13000 hm3

• According to DATADISTA, in Segura basin, the affected water body or in risk by nitrates represents the 38%.

• According to analysis of the Ministry of Environment from 2018, 300.000 tons of nitrates are accumulated in one of the aquifers.

• Regarding to the Tajo-Segura transfer, which was finished in 1979, the original idea was to build a 292 km channel with a capacity to transport up to 33 m3 per second and saving at the starting point a slope of 245 meters in 1070 meters in length. In practice, the average water transferred since 1980 has been less than half of what was expected.

• During dry seasons or when the water from theTajo-Segura transfer has not arrived the 80% of water demand has been satisfied using the groundwater reserves.

• Irrigation has increased tenfold between 1977 and 2017. Almost 25% of the irrigated surface are out of the limits that counted with authorizations os Hydrographic Confederation of Segura. According to a study carried by WWF and ANSE, approximately 12.165,18 ha are illegal.

• The desalination process generates 70% of water suitable for irrigation and 30% of discharge that concentrates salts and nitrates

• According to Seprona’s estimations, four companies may be responsible for the discharge equivalent to 1407 Olympic pools of brine with nitrates to the sea less between 2012 and 2016 that ended directly into the Mar Menor

• GS España and GS Holding España, Inagrup, Ciky Oro and Vanda Agropecuaria (this one when was under the State’s responsibility) may captured 11.750.649 m3 of water from wells between 2012 and 2016. They treated the water in desalination plants and it is estimated that they were able to produce 3,518,462 m3 of brine with nitrates.

• According to the state prosecutor, the two companies have a agricultural surface of 436 ha with an annual water needs of 5.500 m3 per hectare. They also have two desalination plants with capacity of 1.900 m3 and 1.000 m3. Only their brine is equivalent to 316 olympic pools.

• Another example, the company Ciky Oro had three illegal desalination plants that had the capacity to treat 540, 1.200 and 1.000 m3 per day respectively. And had in exploitation between 2012 and 2016 250-500 ha of irrigated land. The estimated brine with nitrates was close to 555 olympic pools

Project area:17,000
Level of Investment:680,000,000
Type of populationSemi-urban
Affected Population:20,000-100,000
Start of the conflict:01/05/2012
Company names or state enterprises:GS España
GS Hlding España
Ciky Oro
Vanda Agropecuaria SL
Relevant government actors:• Confederación Hidrográfica del Segura:
• Ministry of Ecological Transition of Spain:
• Region of Murcia’s government:$m59490
International and Finance InstitutionsEuropean Commission (EC)
Environmental justice organizations (and other supporters) and their websites, if available:The two most important:
• Asociación de Naturalistas del Sureste (ANSE):
• Pacto por el Mar Menor:
Other associations related to environmental topics that support the struggle:
• Ecologistas en Acción Murcia:
• SEO/Birdlife:
• WWF España:
Other local associations that are not focus on environmental topics but that support this cause:
• Cofradía de Pescadores San Pedro del Pinatar:
• Federación de Asociaciones de Vecinos, Consumidores y Usuarios de Cartagena y Comarca:

Conflict & Mobilization

IntensityLOW (some local organising)
Reaction stageMobilization for reparations once impacts have been felt
Groups mobilizing:Farmers
Local government/political parties
Social movements
Trade unions
Local scientists/professionals
Fisher people
Forms of mobilization:Development of a network/collective action
Development of alternative proposals
Involvement of national and international NGOs
Lawsuits, court cases, judicial activism
Media based activism/alternative media
Official complaint letters and petitions
Public campaigns
Street protest/marches


Environmental ImpactsVisible: Biodiversity loss (wildlife, agro-diversity), Loss of landscape/aesthetic degradation, Soil contamination, Surface water pollution / Decreasing water (physico-chemical, biological) quality, Groundwater pollution or depletion
Potential: Desertification/Drought, Food insecurity (crop damage), Soil erosion, Waste overflow, Large-scale disturbance of hydro and geological systems
Other Environmental impactsImpact on Ramsar site
Socio-economical ImpactsVisible: Loss of traditional knowledge/practices/cultures, Loss of landscape/sense of place
Potential: Increase in Corruption/Co-optation of different actors, Displacement, Loss of livelihood, Specific impacts on women


Project StatusIn operation
Conflict outcome / response:Corruption
Court decision (undecided)
New legislation
Under negotiation
Application of existing regulations
Development of alternatives:The regional government approved in December of 2019 new legislation meant to protect the lagoon, and reverse the environmental damage. The central government have also met with local activists, and wants to approve soon a new climate change law that will introduce some measurements to face the environmental crisis.
This platform composed by different environmental, social, cultural, and union groups have proposed ten urgent measurements that future legislation should include in order to protect Mar Menor.
1. Implement a sustainable agricultural model in the surroundings of the lagoon, (campo de Cartagena), compatible with its protection. Authorities should also implement necessary control and surveillance activities to make sure this model is implemented.

2. Start necessary measurement to stop the spilling of nutrients into Mar Menor.

3. Evaluate and improve the state of drainage network with special attention to sewer pipes.

4. Substitute the so called “beach regeneration” with other models able to protect the fragile sea ecosystem.

5. Eliminate o permeabilise infrastructure that obstacles natural dynamics of marine currents (ports and breakwaters).

6. Approve the necessary legislation for protecting the Mar Menor, including sanctions and regulating the activities allowed in area.
7. Implement an integral plan for the prevention of flooding. This should avoid runoffs, land erosion and the spilling of nutrients, plastics and phytosanitary products into the lagoon.

8. Apply the urban moratorium in the surroundings of Mar Menor approved in February 2017.

9. Implement an integral plan for sustainable tourism, able to foment the cultural ecological ethnographical and scenic value of the region.

10. Inform citizenship and concerned sectors with transparency on the situation of Mar Menor, and implement measurements to include them in the decision taking, following current legislation.
Do you consider this an environmental justice success? Was environmental justice served?:No
Briefly explain:Different experts and environmental associations argue that the legislation approved by the regional government is not ambitious enough to protect the lagoon. There is also great skepticism concerning new measures since in 2018 environmental legislation was already approved by the previous central government, but it couldn’t avoid 2019 eutrophication episode.

Sources & Materials

Related laws and legislations - Juridical texts related to the conflict

Ramsar convention.

Barcelona convention for the protection of the Mediterranean sea.

Regional Park: “Arenales y Salinas de San Pedro” and “Calbalanque, Monte de las Cenizas y Peña del Águila”.

Decreto-ley 2/2019, de 26 de diciembre, de Protección Integral del Mar Menor.

Barcelona convention for the protection of the mediterranean sea.

Regional Park: “Arenales y Salinas de San Pedro” and “Calbalanque, Monte de las Cenizas y Peña del Águila”.

Decreto-Ley nº. 1/2017, de 4 de abril, de medidas urgentes para garantizar la sostenibilidad ambiental en el entorno del Mar Menor.

Ramsar convention.

Barcelona convention for the protection of the Mediterranean Sea.

Decreto-ley 2/2019, de 26 de diciembre, de Protección Integral del Mar Menor.

Decreto-Ley nº. 1/2017, de 4 de abril, de medidas urgentes para garantizar la sostenibilidad ambiental en el entorno del Mar Menor.

Bordering the lagoon there are two protected natural spaces under the figure of Regional Park: “Arenales y Salinas de San Pedro” and “Calbalanque, Monte de las Cenizas y Peña del Águila”.

Common Agricultural Policy

References to published books, academic articles, movies or published documentaries

Moreno, Pedro & Ibarra Marinas, Daniel & Balibrea, Jorge. (2018). La Burbuja del regadío: El caso del Mar Menor. 10.13140/RG.2.2.33484.72320.

Links to general newspaper articles, blogs or other websites

Redacción de El Salto Diario. “No es la DANA”: los ecologistas culpan a la agroindustria y las administraciones del colapso del Mar Menor. Published on october 14, 2019(Newspaper article in El Salto Diario)

Esther Sánchez. La asfixia del mar menor. Published on october 20, 2019 (newspaper article in El País)

Cristina Crespo Garay. La agonía del Mar Menor: así hemos llegado a su colapso ecológico. Published on october 23, 2019 (Article in National Geographic)

Esther Sánchez. Murcia aprueba un decreto ley para recuperar el mar Menor pero admite que no es suficiente. Published on dicember 26, 2019 (newspaper article in El País)

Antonio Delgado y Ana Tudela. Mar Menor: historia profunda de un desastre. October, 2019 (Report in Datadista)

Pablo Rivas. Mar menor, ecocidio anunciado. publicado el 8 de diciembre de 2019.(newspaper article)

Redacción de El Salto Diario. “No es la DANA”: los ecologistas culpan a la agroindustria y las administraciones del colapso del Mar Menor. Published on 2019 october 14 (Newspaper article in El Salto Diario)

Pablo Rivas. Mar menor, ecocidio anunciado. Published on december 8, 2019.(newspaper article in El Salto Diario)

Related media links to videos, campaigns, social network

Asociación de Naturistas del Sureste

Pacto por el mar menor

Ramsar Spain

Meta information

Contributor:Students of the Master in Political Ecology, Degrowth and Environmental Justice (Guillermo Fernández, Sara Gil and Mario Diaz)
Last update20/05/2020



Peces muertos en la costa de San Pedro del Pinatar (Murcia)

The image shows several dead fishes as consequence of an eutrophication episode. Retrieved from (

55.000 personas se manifiestan en Cartagena para salvar el Mar Menor

Hundreds of people protest in the streets of Cartagena demanding measures to save the "Mar Menor". Retrieved from RTVE(

Mar menor

Image of the "Mar Menor" afected by an eutrophication episode. Retrieved from Público (

El Mar Menor visto desde el satélite de teledetección SPOT.

Satellite image of the"Mar Menor" and its surroundings. Retrieved from El País. (