Reduced freshwater flow into the Wadden Sea has harmful consequences for plant and animal life in the region, the Royal Netherlands Institute for Sea Research (NIOZ) said.
The warmer spring and summer months and the increased retention of water for agriculture and consumption, reduce the flow of water into the Wadden Sea, the world’s largest system of tidal flats located near the Frisian islands. This affects the natural salt gradient of the water, from fresh to salty water, which harms algae. Freshwater contains nutrients (such as phosphate and nitrogen) that are essential for growth of microalgae.This in turn impacts the food web of the area. This is an issue that requires greater attention, according to the recent Wadden Sea Quality Status report.
“Increasing temperatures and rising sea levels are on everyone’s mind now. But that fading salinity gradient is something we have overlooked for a very long time,” says the director of the Wadden Academy and scientist at the NIOZ, Katja Phillippart, in a NIOZ press release.
The Wadden Sea Quality Status report was written collaboratively by experts from the Wadden Sea region, namely the Netherlands, Denmark, and Germany. In addition to the salt gradient issue, the report alerts for the death of shellfish caused by higher temperatures and the accelerated rise in sea level. Part of the solution for concerns lies in better water management.
“To tackle warming and sea level rise, there is only one thing we should do: reduce our greenhouse gas emissions worldwide. Freshwater runoff to the Wadden Sea, however, is something that can be addressed locally as well. More water storage in winter, for example, provides more options for use in drier periods, including discharge to our coastal waters,” says Phillipart.
Last week, a vessel dedicated to coastal research in the North Sea, the Delta, and the Wadden Sea was christened. The vessel will further enlighten specialists of the systemwide impacts of heatwaves and droughts.
(Image credit: CWSS/ Martin Stock)
