The water in the Wadden Sea is becoming increasingly salty. This is because much less fresh water is pumped into the Wadden Sea. This is evidenced by new, not-yet-published research seen by RTL News. The consequences are dire: this coastal sea is slowly turning into a completely salty sea, with a major impact on shellfish, fish and birds.
The research also shows that the first tidal flats will “submerge” within a few years. This means that it will no longer dry out as a result of sea level rise. Even under a moderate climate scenario, tidal flats will disappear in some parts of the Wadden Sea from 2030. This also brings about major changes.
This changes the composition of the soil and soil fauna, which also has consequences for the birds and fish that depend on them. Now millions of migratory birds come to the Wadden Sea only because they can find food on the dry tidal flats. If the number of dry dishes decreases, there will also be less food.
“Stronger, faster, worse”
All data are contained in an international study published once every few years. Changes in the Wadden region are being inventoried for this report by scientists from the Netherlands, Germany and Denmark, on behalf of these three countries.
Compared to the previous report issued in 2017, what is particularly striking is the increasing salinity of the water and the acceleration of sea level rise. This is what researcher Katja Phillipart, a professor at Utrecht University who works at the Royal Institute for Marine Research (NIOZ), says. She also co-wrote a similar report in 2017 and the report released in 2009. She was once again shocked by the results.
“Every time you look forward and every time reality overtakes you. Every time it is stronger, faster and worse than you ever imagined.”
Less nutrients
The fact that less fresh water ends up in the Wadden Sea also means fewer nutrients, such as algae, for the oysters to eat. These, in turn, provide food for all types of migratory birds that settle in the Wadden Sea twice a year. The number of 10 to 12 million migratory birds is an important reason why the Wadden region is… World Heritage Status Received, says Philippart.
“But also because this is a nursery for young fish. Fish that are born in the North Sea come here to grow up and then return to the North Sea. We are seeing changes there too. This is probably mainly due to rising temperatures.” The water has gotten too warm for those fish to stay here long.
The most important thing that needs to happen now is to reduce carbon dioxide emissions in the Netherlands, says Philippart. But tackling climate change will require the whole world to take action. What the Netherlands has complete control over is the amount of fresh water that reaches the Wadden Sea.
New research ship
NIOZ today put a new vessel into use for scientific research in the Wadden Sea and the North Sea: the Wim Wolff. In the coming decades, this vessel will be used to conduct research from the Danish to the Belgian coast.
One device takes measurements in seawater continuously, without the need for humans. “It pumps seawater up, and that goes through the system,” says Bram Fay, the ship’s captain. “It has different sensors, including temperature and salinity, and that is automatically recorded in the database.”
The ship has been made as sustainable as possible: it runs on biodiesel and also has a large battery on board. It has a flat bottom, so it can dry on mud flats.
The average spring freshwater discharge from all rivers into the Wadden Sea has almost halved over the past 20 years, from 300 to 175 cubic meters per second. Philippart believes it is understandable that a lot of fresh water is retained on Earth due to severe droughts in recent years.
However, she says: “You see the call everywhere: hold on to it, because we need it. But what we forget is that the Wadden Sea also needs fresh water. So, in all these discussions about fresh water, we also have to take into account the The need for fresh water in the Wadden Sea.”
