No quick fixes are in sight for the collapsed ecosystem of Mar Menor, Europes biggest saltwater lagoon. But environmental experts say that could actually be a good thing.
The Mar Menor lagoon, a triangle of warm, shallow water that draws crowds of tourists to southeastern Spain, has suffered repeated mass die-offs of fish and vegetation blamed on chronic pollution from farms, mines and urban areas.
Public outrage at the degradation has prompted Spains largest-ever investment in the restoration of a region. A long-term revival plan is focused on tackling the deep-rooted causes of the crisis. Full implementation could take decades. But success could give the whole region a more sustainable future.
I think its a great idea, Isabel Rubio, a spokesperson for Pact for the Mar Menor, a group pushing to save the lagoon, said of the approach. The ideas are based on nature. I think if there is any salvation for the Mar Menor, it will come from there.
In recognition of its scope and potential, the governments restoration initiative has been named as a United Nations World Restoration Flagship. The award is part of the UN Decade on Ecosystem Restoration and recognizes outstanding efforts to protect and revive the natural world.
Tackling environmental problems needs commitment, collaboration, science and dedication, says Natalia Alekseeva, a Principal Coordination Officer with the UN Environment Programme (UNEP). Spanish leaders and the defenders of the Mar Menor deserve credit for one of the most comprehensive and far-sighted restoration plans that Europe has ever seen.
Rubio, a retired schoolteacher and local resident, has witnessed the decline of the Mar Menor over a lifetime. She recalls spending whole days of her childhood playing and picnicking in its dunes and sheltered coves. On retirement, she took up underwater photography and started a website documenting the Mar Menors dazzling aquatic life.
"What I could not imagine is that 15 years later I would be faced with the disaster that appeared, says Rubio. In 2015, I started to notice that the water was getting darker. I began to see that many of the species I had seen were diminishing. Last year, I hardly saw any."
Green soup
The Mar Menor provides crucial ecosystems services, including supporting unique biodiversity and offering significant cultural and economic benefits like tourism, recreation and fishing. But it has been pushed to the brink.
Experts had long warned that unsustainable development in the surrounding region of Murcia was overloading the lagoon with nutrients, a process known as eutrophication.
Murcia, fed by water transfers from the north, has become a mass producer of fruit and vegetables, much of it for export. But fertilizer spread on the intensively farmed crops has leached into streams and groundwater, and from there into the lagoon.
Heavy metals from disused mines in the nearby Sierra Minera hills added to the problem, as did pollutants from the houses, hotels and marinas that crowd around the lagoon.
In 2016, the Mar Menor could absorb no more. A proliferation of nutrient-fed phytoplankton turned the water into green soup, according to media reports. Scientists found that more than 80 percent of the seagrass meadows on the bed of 135-square-kilometre lagoon died for lack of light, replaced by thick mud. Three years later, floodwaters following heavy rain dumped an estimated 100150 tonnes of dissolved phosphates into the water, triggering the mass death of fish, seahorses and other marine creatures, found a government report. In 2021, there was another die-off of fish, crabs and mollusks.
Many people in the region and beyond were outraged. Tens of thousands protested in cities such as Murcia and Cartagena calling for action to save the Mar Menor. More than 500,000 signed a petition asking for the lagoon to receive stronger legal protection.
In response, Spains government presented a framework of priority actions to halt and reverse the degradation of the lagoon. Parliament, meanwhile, passed a landmark law granting the Mar Menor legal personality and a right to exist and be protected a first in Europe. And regional lawmakers tightened the regulation of land use.
For us, of course, it was a ray of hope, said Rubio.
Tackling the causes
Armed with a budget of 675 million euros, project managers began implementing the governments restoration framework in 2021. The plan includes dozens of on-the-ground restoration actions.
An urgent priority is creating a 1,500-meter-wide green belt around the lagoon, including a series of artificial wetlands as well as rehabilitated sand dunes and other restored natural areas. Some wetlands are being paired with green filters, where pumped groundwater is passed through vegetation that absorbs most of the pollutants.
One high-profile measure expected to begin soon is the dismantling of a controversy-plagued marina on the sandbank that divides the lagoon from the Mediterranean Sea. But much of the plan is devoted to addressing the pollution that has beset the lagoon at its most important sources.
The issue was so profound, so complex, that we felt we had to go to the pressures and root causes, says Francisca Baraza, Commissioner for the Water Cycle and Ecosystem Restoration in Spains Ministry for Ecological Transition and the Demographic Challenge. So, for us, the watershed was the fundamental scenario for intervention.
For example, rivers and canals running through farmlands in the wider catchment will be re-naturalized with trees and plants to cut the amount of water, sediment and pollutants that reach the lagoon. Embankments are to be lowered in some places to create floodplains.
The initiative is also supporting restoration measures to reduce soil erosion and foster a shift to more sustainable farming. For example, grants have been awarded for projects promoting organic or regenerative agriculture and techniques requiring less fertilizer. Assistance targeting livestock farmers the region hosts hundreds of pig farms is also in the pipeline.
In the Sierra Minera, reforestation activities and restored watercourses are to prevent contaminants in mounds of waste near abandoned mining operations from posing a hazard to nearby residents or finding their way to the lagoon.
Other key elements of the framework include a comprehensive water-monitoring operation, a research programme to improve understanding of the regions interlinked ecosystems, biodiversity conservation measures and extensive public outreach.
The consultations with businesses, residents and other stakeholders are designed not only to smooth the implementation of the restoration activities but also to develop a vision of the Mar Menor in 2050 and a plan of action to realize it.
More than optimism, what I have is a lot of hope that this can be turned around, said Rubio, the spokesperson and retired schoolteacher. Because human beings know how to destroy. But we also know how to build, we know how to recover, we know how to conserve and we know how to protect.
The UN General Assembly has declared 20212030 a UN Decade on Ecosystem Restoration. Led by the UN Environment Programme and the Food and Agriculture Organization of the UN, together with the support of partners, it is designed to prevent, halt, and reverse the loss and degradation of ecosystems worldwide. It aims at reviving billions of hectares, covering terrestrial as well as aquatic ecosystems. A global call to action, the UN Decade draws together political support, scientific research, and financial muscle to massively scale up restoration.
