New study led by BC3 and Ikerbasque researchers Violeta Cabello and Marcela Brugnach analyzed the narratives and uncertainty surrounding the dispute over the overfertilization of the Mar Menor lagoon in Spain.

Harmful algal blooms, dead zones, and fish kills are the results of eutrophication – a process that occurs when the environment becomes enriched with nutrients, mostly nitrogen and phosphorous, increasing the amount of plant and algae growth to estuaries and coastal waters.

The Mar Menor lagoon is a protected aquatic area in Southeastern Spain that has been receiving nutrients from poor sewage systems, fertilizers and discharge from mining activities over the last five decades. Early in the 2000s, scientists started warning that the lagoon could become eutrophicized. In 2016, its waters turned green when algal blooms killed off 85% of the vegetation on its seabed. Later in 2019, an event of anoxia – depletion of oxigen in the water – produced tons of death aquatic biota.

In this study, researchers explored the narratives that explain the causes and potential solutions to the lagoon’s crisis. Results show two increasingly polarized narratives that deviate in the causes for nutrient enrichment and the type of solutions seen as effective: (1) intensive agriculture is the main driver for the Mar Menor eutrophication; and (2) the lagoon has many and complex pressures, agriculture is only one of them.

The authors further analysed the role of uncertainty in this polarization dynamics. Findings revealed how different uncertainties are mobilized to dispute the centrality of agriculture, like the lack of data on water and fertilizer use.

This research contributes to understand eutrophication as an intertwined social-ecological phenomena and how knowledge production can contribute to sharp polarization. Researchers concluded that different inter- and transdisciplinary approaches may be needed to address existing uncertainties.

This research is part of the groundwork for initiating a knowledge co-creation process with local actors in the Mar Menor lagoon. By using participatory methodologies and dialogue techniques, we will critically examine identified dominant narratives and seek common ground among divergent perspectives over how to revitalise this emblematic aquatic ecosystem. (Violeta Cabello, BC3 researcher)