The Mar Menor, once a thriving marine ecosystem, is now facing an ecological crisis of unprecedented proportions. According to a recent report by the Spanish National Research Council (CSIC), the situation has become dire. Furthermore, there are no signs of recovery in the lagoon’s seabed.
Despite efforts to restore the area, the degradation continues. A degradation exacerbated by the rising temperatures and marine heatwaves associated with climate change.
On August 13th, Juan María Vázquez, the regional minister for the Environment, presented findings that seemed promising at first glance. The report claimed that the lagoon had seen an expansion of vegetative cover across 92% of its surface. However, CSIC scientists have since raised serious concerns. They pointed out that the reality is far more troubling. Their long-term monitoring of the seagrass meadows, particularly the Cymodocea nodosa species, shows no signs of recovery over the past five years.
The disappearing seagrass and the white stain
The report reveals that there has been no recovery. Furthermore, the seagrass meadows have actually retreated. A staggering 615 hectares of Caulerpa prolifera meadows have vanished. Swallowed up by the murky waters forming what scientists describe as the “white stain”. This is just one of many symptoms of the lagoon’s vulnerability to the progressive warming and nutrient pollution that threaten its delicate ecosystem.
Marine heatwaves, which have become increasingly frequent, are merely the “tip of the iceberg” in what CSIC describes as a broader pattern of ocean degradation. With its deteriorating water quality and collapsing habitats, Mar Menor is at high risk of repeating the catastrophic ecosystem collapse witnessed in 2016 unless urgent measures are taken to reduce nutrient inflows and other stressors.
A call for urgent action
The broader picture painted by CSIC is concerning. The state of Spain’s marine waters is described as “uneven”. Some areas are relatively well-preserved due to environmental protection measures, while others, like the Mar Menor, are severely impacted. Despite significant public funding and the implementation of European regulations aimed at preserving marine environments, the Mar Menor’s situation exemplifies the challenges that remain.
The threats are manifold, including warming and acidification of the seas, eutrophication, oxygen depletion, invasive species, coastal pollution, overfishing, and plastic pollution. Additionally, changes in ocean currents, reduced capacity to sequester atmospheric CO2, and the emergence of large hypoxic regions with the potential to become oceanic deserts are pressing concerns.