Murcia and Madrid disagree on root of Mar Menor issue

The environmental troubles of the large lagoon have led to a political blame game

The Mar Menor lagoon in Murcia (on the Spanish eastern coast) has caused concerns in recent weeks over its environmental health after more than five tonnes of dead fish have washed up on its shores. The large die-off is due to lack of oxygen, or apoxia, a regular issue in the lake in recent years. What causes that phenomenon, however, seems to be something of a source of contention. It has even led to a blame game between the regional and national governments.

The Murcian administration has called on Madrid to invest in a proposed plan for the creation of a collector plant that would denitrify the run-off waters resulting from farming activity in the areas near the lake. The central government, represented by Teresa Ribera, the Minister of Ecological Transition, countered that such a measure would only be ‘whitewashing’ the problem rather than fixing it. For her, the cause of the environmental disaster are illegal farming practices, such as desalination plants

Once a magnet for tourists, today Mar Menor is something akin to ‘green soup’

Environmental activists, residents and tourists are not impressed with the political back dealings and sluggishness, given that the degradation of the lagoon is not new since biological mass die-offs were recorded in 2016 and 2019.

The water apoxia in the salty lake is caused by nitrates and phosphates coming in through the Rambla del Albujón stream, which empties the fresh water from an aquifer collecting excessive rainwater. Those chemical nutrients are ingredients used in farming fertilizers and their accumulation helps the overgrowth of phytoplankton.

The green layer of the phytoplankton biomass blocks the sunlight from reaching the bottom of the lake and also consumes the oxygen from the water, in essence suffocating the fish and crabs living under it. Additionally, summer months with their lack of wind and lower levels of water contribute to the exacerbation of the problem.

"We know what to do and we are willing to do it, we just need to be allowed to do it," exclaimed Fernando López Miras, the President of Murcia, revealing a sense of frustration.

For the time being, the regional government has started cleaning one of the gullies that connect Mar Menor to the Mediterranean Sea in an effort to oxygenate the water body, although the Ecological Ministry had said that this would likely not be an efficient solution.