Only a few years ago, the clear, shallow waters of Mar Menor, a saltwater lagoon off eastern Spain that is Europe’s largest, hosted a robust population of the highly endangered fan mussel, a meter-long bivalve. But in 2016, a massive algal bloom, fueled by fertilizer washing off farm fields, sucked up the lagoon’s oxygen and killed 98% of the bivalves, along with seahorses, crabs, and other marine life.

The suffocating blooms struck again and again, and millions of dead fish washed onto shore. In 2021 local residents—some of whom benefit from tourism to the lagoon—had had enough. Led by a philosophy professor, activists launched a petition to adopt a new and radical legal strategy: granting the 135-square-kilometer lagoon the rights of personhood. Nearly 640,000 Spanish citizens signed it, and on 21 September, Spain’s Senate approved a bill enshrining the lagoon’s new rights. The new law doesn’t regard the lagoon and its watershed as fully human. But the ecosystem now has a legal right to exist, evolve naturally, and be restored. And like a person, it has legal guardians, including a scientific committee, which will give its defenders a new voice.

The lagoon is the first ecosystem in Europe to get such rights, but this approach to conservation has been gaining popularity around the world over the past decade…The clearest success story, scholars say, is the Whanganui River in New Zealand, which was given legal rights by an act of Parliament in 2017. Like a person, the river and its catchment can sue or be sued, enter contracts, and hold property. In that case, the aim was not to stop pollution but to incorporate the Māori connection between people and nature into Western law. “The river and the land and its people are inseparable,” Niko Tangaroa, a Māori elder of the Whanganui Iwi people and a prominent activist for the river, wrote in 1994.

Excerpts from Erik Stokstad, This Lagoon is Effectively a Person, New Spanish Law Says, Science, Oct. 7, 2022