Underwater gardeners in Denmark are planting algae to restore the fjord’s ecosystem

Under a tent along a fjord in western Denmark, volunteers and scientists prepare seaweed plants before transferring them into the water to restore the ecosystem of this hard-hit bay by deoxygenating it.

In the Scandinavian country, which enjoys a good ecological reputation, 7,500 km2, or 17% of the total area, is affected by the problem, according to the Danish Environment Agency, which classifies only five out of 109 coastal areas as having “good ecological status”.

Without oxygen, marine fauna and flora disappear. In Vejle, an underwater surveillance camera installed by the municipality detected only one fish in 70 hours.

In Denmark, where more than 60% of the country’s surface is devoted to agriculture, one of the highest shares in the world, alarm bells continue to ring.
In 2022, a report from the University of Southern Denmark highlighted the “poor environmental condition” of this 22 km long fjord, due to the high presence of fertilizer nitrogen “most of which comes from diffuse runoff from cultivated areas.

And when the mercury rises, problems pile up.

“We had a very hot summer in 2023, which led to a big decrease in oxygen,” Mads Fjeldsoe Christensen, a biologist working at the city hall, confirmed to AFP. “It was pretty bad, we saw a lot of dead fish.”

In order to mitigate this ecological tragedy, scientists and the municipality decided in 2018 to re-introduce sea grass that helps restore the underwater environment.

In areas that still thrive, scientists collect the plants, then on land, volunteers wrap the wavy shoots around a degradable nail so that divers can easily attach them to the seabed.

This is the first step to improve the condition of the fjord, whose ecosystem has collapsed in recent years.
“Eelgrass (or seaweed, editor’s note) is where all fish grow, it’s like a nursery for them. If you don’t have eelgrass, there’s simply no ‘room for the fish population to grow,'” says Mr. Fjeldsoe Christensen.

– The return of aquatic life –

Since the beginning of the project, more than 100,000 plants have been planted on six hectares of the seabed.

In some places, divers are now rediscovering aquatic life, with crustaceans and fish.

“We are seeing the effects of the restoration of nature,” says biologist Timi Banke from the University of Southern Denmark (SDU), who is participating in the project.

However, in April Greenpeace organized an open-air fjord funeral to draw attention to the poor health of the country’s coastal waters.

“It’s in a bad state, that’s why we’re doing something, but it’s not dead,” assures the scientist who welcomes the mobilization of non-governmental organizations and the local population.

In Vejle, about fifty volunteers came to help the scientific teams despite the very gloomy weather.
On World Ocean Day, June 8, the think tank “Taenketanken Hav” organized seagrass planting operations in 32 locations across the country.

“By planting eelgrass, we emphasize the restoration of nature, but this does not mean that we have to forget that we also have to reduce nutrient emissions into Danish waters” with degraded quality, explains the director general of the non-governmental organization Liselotte Hohwy Stokholm, on her website.

Written by James BROOKS – © 2024 AFP

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