Freshwater salinization has severe consequences for ecosystems (such as biodiversity loss or changes in the carbon cycle) and for people (including lack of drinking water, health problems, or impacts on livelihoods such as farming, fishing, or mollusk harvesting). One of the areas where this issue is wreaking havoc is the Gambia River in West Africa, which is experiencing a significant rise in salinity due to prolonged drought. This situation is expected to worsen due to rising sea levels and the construction of a massive dam that would substantially reduce water flow.
For the first time, a research team is studying the salinization of this river and its impacts. The team has begun identifying, quantifying, and describing its effects on various key aspects, including changes in aquatic biodiversity, impacts on greenhouse gas emissions, damage to mangrove areas, and effects on local populations. These researchers, experts in fields such as biogeochemistry, biology, ecology, geology, and social sciences, hail from research centers and universities in Africa, Australia, and Europe. Among them are the Institute of Environmental Assessment and Water Research (IDAEA-CSIC), the Blanes Center for Advanced Studies (CEAB-CSIC), and the University of the Balearic Islands (UIB).
“We aim to understand both the changes in processes occurring within the river and its natural surroundings due to increasing salt concentrations and the effects on local communities that depend on it,” explains Núria Catalán, a CEAB-CSIC researcher and team member.
The research seeks not only to understand the effects of rising salinity in this African river but also to provide a global perspective on the issue of freshwater salinization. According to Miguel Cañedo-Argüelles, an IDAEA-CSIC researcher, this problem “is global and increasing due to the combined effects of climate change and growing demand for resources.” The project aims to generate evidence to develop strategies applicable wherever similar conditions arise, with one key objective being the co-creation of solutions with local populations.
The team emphasizes that the results of the SALBIA research project should serve both locally, by contributing to better management of the Gambia River, and globally, by offering a model to address salinization issues in other regions.
“We hope this work provides useful tools for the sustainable management of aquatic ecosystems in areas vulnerable to salinization and helps co-design potential adaptation strategies,” say Pablo Rodríguez Lozano, a UIB researcher, and Miguel Cañedo-Argüelles from IDAEA-CSIC.
Preliminary Results
According to initial findings from the first sampling campaign conducted this summer, salinity is altering the river’s biodiversity patterns. Distinct organism communities were identified along the salinity gradient.
Additionally, salt levels influence how carbon moves and transforms in the river, affecting greenhouse gas emissions, such as CO2, from both water and sediments. Higher emissions of greenhouse gases were observed in the saltiest areas, particularly in the lower reaches of the river.
A second sampling campaign is scheduled for early 2025 to continue gathering information on the environmental and socio-economic effects of freshwater salinization.
