Mar Menor (“Minor Sea” or “Smaller Sea” in English) is a semi-closed ecosystem in southern Spain's Murcia that has been suffering from decades-long abuse from human activity. The lagoon has been  deteriorating mostly because land management in the region has allowed fertilizers and other chemicals from the fields in the area to be released into Mar Menor.

Once in the lagoon, these chemicals destabilize the marine environment, causing a condition called eutrophication, which provokes the growth of phytoplankton and reduces the amount of oxygen in the water. 

The lagoon connects with the Mediterranean Sea through a few channels which make it extremely vulnerable to external conditions, like torrential rains. This happened in September 2019, when the region was hit by some of its worst storms in over a century.

The floods that resulted from these storms compacted the lagoon's existing problem by dragging in more pollutants, mud and nitrates from fertilizers. A few weeks later, in October, thousands of fish and other marine life were washing up dead on the shores of the lagoon. They suffocated due to lack of oxygen in the water, a condition called anoxia.

The images of the dead fish became a symbol of Mar Menor's collapse. After October's catastrophic incident, the Spanish Oceanographic Institute (SOI), in collaboration with other bodies, published an extensive study on Mar Menor. According to Rafael Gonzalez, deputy director of SOI, this study can now provide them with a better understanding of the ecosystem and help them find solutions to save it.

“The solutions need to be slowing down the elements that are responsible for this eutrophication and for the increase in nutrients in Mar Menor as a consequence of human activity,” Gonzalez said, referring to the intensive farming in the area.

At the same time, there is an important tourism industry in that depends on the lagoon. Hotels have demanded immediate action and have expressed concerns that if Mar Menor doesn't recover ahead of the tourist season, there will be losses, closures and even jobs lost in the tourism sector.

The quality of the water has improved since October, yet the underlying problems remain. The president of the regional government in Murcia recently stated that every second, 204 liters of polluted water enters Mar Menor via the Albujon watercourse.

Mariam Perez, the general director for Mar Menor in the Murcia government, said that on a local level, the government does all it can to stop the environmental catastrophe of Mar Menor. It spent over $8.8 million to clean the lagoon after the September floods.

“We will also take other actions, like create a bank of species, a kind of Noah's ark, to preserve the animals that are native in Mar Menor, so if anything bad happened in the future we could repopulate the lagoon," Perez said. 

"Also we're looking for shore wells in the underground that might have water with the same conditions as the Mar Menor so we can oxygenate it but one of the most important measures is in the competence of the central government and that's the pumping of the Albujón watercourse to avoid the chemicals reaching Mar Menor.”