On a warm spring morning, the Mar Menor lies flat and calm, its sprawling surface glistening under the sun. Sandy beaches are dotted with flocks of seagulls, herons, and cormorants, while volcanic islands rise majestically on the horizon. The water, clear and inviting, gently laps against the shore.

Stretching 52 sq. miles along the coast of the south-eastern Spanish region of Murcia, the Mar Menor is Europe’s largest saline lagoon. Its warm shallows and the region’s mild, year-round climate have made it a premier tourist destination and a popular retreat for retirees. But beneath the surface of apparent calm a severe ecological crisis has been brewing as a result of decades of agricultural runoff, urban development, and tourism, which have each played a part in destabilizing the lagoon’s ecosystem.

Experts say the agricultural boom in the countryside surrounding the lagoon has had the most significant impact. Once a pastiche of small, family-run farms, the area grew into to a major agricultural hub after a canal brought irrigation water from the Tagus River, the longest in the Iberian Peninsula, in 1979. Today, the region, also known as “Europe’s orchard,” produces over 2.5 million tons annually and accounts for about 20 percent of Spain’s fruit and vegetable exports.

This shift to monoculture farming beginning in the 1980s introduced excessive nitrogen and phosphorus from synthetic fertilizers, which seeped into Mar Menor through runoff and rainfall. Hundreds of private desalination machines, installed to make brackish groundwater suitable for irrigation, also started dumping nutrient-rich brine into channels that drain into the lagoon.

The development of tourism and urban areas further exacerbated the problem. As the region gained popularity as a tourist destination, developers rushed to erect hotels and holiday homes to cater to the influx of newcomers. Many of these building, lacking proper drainage systems, discharged untreated sewage directly into the lagoon.

For decades, coastal salt marshes, seaweeds, and other marine species filtered out the excessive nutrients, allowing the Mar Menor to maintain an increasingly fragile equilibrium. But in the spring of 2016, the lagoon could no longer withstand the strain and experienced extreme eutrophication.

Feeding on nutrients in the water, rafts of algae, some stretching kilometers, shrouded the lake’s surface, turning the water green and blocking sunlight from reaching the bottom. Unable to photosynthesize, most of the vegetation died and as the algae decomposed, fish and crustaceans washed ashore in droves, dead or dying due to lack of oxygen.

“What we saw those days went beyond the worst we could ever have imagined — death on a massive scale,” says Nat Llorente Nosti, an activist with the environmental nonprofit Ecologistas en Acción, adding that the scientific community had been warning about it for decades, but to no avail.

Two major incidents followed. In October 2019, over three tons of fish and crustaceans washed up north of the lagoon after a storm dumped unprecedented rainfall in the area. Then, in August 2021, the lagoon faced its most severe crisis yet when around five tons of fish beached up on the shores of La Manga — a narrow sandbar separating the Mar Menor from the Mediterranean Sea.

In the following days, scores of protesters wearing black ‘SOS Mar Menor’ t-shirts gathered on the shore of the lagoon, mourning for the death of the animals and asking for measures to protect their beloved lagoon. It was then that one local came with up a bold new idea: What if Mar Menor was given the same legal rights as a person? What if it had a right to exist and protection against the damage being done to it?

Teresa Vicente, 61, a professor of philosophy of law at the local University of Murcia, had been thinking about that since 2019. Back then, she was on a three-month fellowship at the University of Reading, in the United Kingdom, studying how other countries have legally protected natural resources. One day one of her students from Murcia called up to inform her about the situation unfolding in the Mar Menor.

“I almost immediately went back home because I wanted to put the theory into practice,” explains Vicente.

The concept of “granting rights of nature” has long been around, but it has gained traction only in recent years. In the past decade, ecosystems like Colombia’s Atrato River and New Zealand’s Whanganui River were granted legal personhood.

Inspired by these examples, Vicente drafted a bill that would grant Mar Menor legal personhood, and she and her team started gathering the 500,000 signatures needed to take it to Spain’s Parliament, which allows citizens to propose laws directly. To spread the word, Vicente penned an article for a local paper. She also rallied support from communities along the riverbanks who were furious about the pollution right in their backyard.

By 2021, Vicente had amassed over 600,000 signatures. Public rallies, meetings with government officials and media interviews promoting the legislation followed until September 2022, when Spain’s senate passed the bill into law, giving the Mar Menor the legal right to conservation, protection and damage remediation.

“I never doubted we would succeed,” says Vicente, who was awarded the prestigious Goldman Environmental Prize earlier this year for this historic achievement. Mar Menor is the first, and so far the only ecosystem in Europe to be granted legal status as a person. “People really came to understand they were part to the ecosystem and were thrilled at the prospect to stand up for their rights,” she says.

Nearly two years after the law was passed, the Mar Menor has not miraculously recovered, but thanks to recent measures implemented by local authorities, the situation is gradually improving. And while a full restoration of the lagoon is unlikely, Vicente remains steadfast in her belief that there is a future for the Mar Menor.

“We won’t return to the same ecosystem,” she says. “But at least we can hope to restore something similar.”

Reporting for this story was supported by Journalismfund Europe.