The Mar Menor lagoon has initiated its first oyster reef project to address pressing pollution issues, coinciding with warnings from scientists about dangerously low oxygen levels in the water. Following Storm Alice, researchers from the Spanish Institute of Oceanography and environmental group ANSE have commenced open-sea trials to evaluate the effectiveness of native flat oysters in filtering pollutants and enhancing water quality.

Approximately fifty-five thousand young oysters, bred at the Murcia Oceanographic Centre, have been strategically placed on a reef near Isla del Barón. These oysters are estimated to retain up to one hundred tonnes of nitrogen annually, which represents about a fifth of the total nutrients entering the lagoon each year. Project coordinator Marina Albentosa stated, “The goal is to study how oyster farming can naturally reduce pollution in the lagoon.”

Oysters serve as a natural ecological cleaning system, with projections indicating that they could filter all the lagoon’s water within just twenty-three days, bringing optimism for a sustainable resolution to the lagoon’s persistent nutrient overload. However, researchers including Juan Manuel Ruiz have reported alarmingly low oxygen levels, particularly in the southern region, attributing this to the influx of fresh rainwater that inhibits oxygen circulation.

Currently, oxygen levels at the bottom of the lagoon are recorded at one point five milligrams per litre, dangerously close to anoxic conditions. Such low levels have previously resulted in significant fish and crustacean die-offs. While the oyster project holds promise for the lagoon’s long-term recovery, experts underscore the necessity for immediate actions to avert an environmental disaster in the Mar Menor.