The Mar Menor is facing significant contamination concerns linked to heavy metals from historical mining activities in the Sierra Minera region of Cartagena and La Unión. These activities flourished from the late nineteenth century into the twentieth century. Several watercourses originating from this area have deposited contaminated sediments into the southern basin of the lagoon, which include harmful elements such as lead, mercury, arsenic, copper, zinc, and silver.

Recent years have seen an increase in interest from various academic institutions, including the Autonomous University of Barcelona and the Oceanographic Institute, as well as the Polytechnic University of Cartagena. Their research, part of the Opal Project, delves into the influx of nutrients, metals, and contaminants resulting from human activities in the Mar Menor.

Urban expansion in recent decades has also exacerbated the concentration of these harmful chemical elements, stoking worries about the environmental health of this unique lagoon. The connection between historical mining and modern urban development underlines a growing need for awareness and action regarding the protection of Mar Menor’s ecosystem.

As ongoing studies continue to highlight the severity of the contamination issues, the future of the Mar Menor hangs in the balance, with many advocating for increased measures to mitigate these environmental impacts.