Freshwater scarcity is not just impacting land ecosystems; it is having dramatic effects on marine life as well, particularly within the Mediterranean Sea. A recent study has unveiled the worrying consequences of reduced freshwater flow due to climate change and increasing water demands, projecting significant declines in marine productivity and commercial fisheries.
The Mediterranean, situated among southern European countries, faces severe water stress, with close to 20% of Europe experiencing water shortages annually. Projections suggest river discharge could decrease by up to 40% by 2050, which is likely to disrupt the delicate balance of oceanic ecosystems.
Researchers from the European Commission's Joint Research Centre (JRC) have used the Blue2 Modelling Framework to predict the consequences of reduced freshwater inflow on marine biogeochemistry and productivity. They found up to 41% reduction in river flow could lead to declines of 10% or more in marine primary productivity, impacting various marine species reliant on these conditions for spawning and growth.
Specific areas like the Adriatic Sea could see even more drastic reductions, with estimates showing productivity cuts of up to 30% or higher based on local conditions. Notably, biomass of commercial fish and invertebrates is also expected to plummet, with the model indicating impacts disproportionately affecting regions where fishing intensity is high.
Prior studies have highlighted the significant roles freshwater ecosystems play, and this new research emphasizes the need to reassess current water management strategies. "The negative impacts of the EXT water-reduction scenario... are substantially more important for marine ecosystems than those of the NUTS scenario where only the water flow is reduced," noted the researchers.
This alarming trend poses not just ecological challenges, but economic ones as well. The Mediterranean fisheries sector, which supports around 65,000 fishers and contributes significantly to the regional economy, might face potential losses of €4.7 billion per year as fish and shellfish stocks dwindle due to diminishing aquatic productivity.
Sound management and the implementation of Integrated Water Resource Management (IWRM) principles are deemed urgent for safeguarding both freshwater and marine ecosystems. "This has the potential to disrupt regional ecosystems and severely affect the fisheries sector and the associated economic activities of the coastal communities," the researchers warn.
Addressing these interconnected challenges requires adopting holistic strategies, taking full stock of both land and sea water needs, and ensuring sustainability amid growing human demands on this precious resource.