Greenpeace plants red warning flags in Vejle Fjord

Greenpeace planted two red flags in Vejle Fjord after finding moderate oxygen depletion bordering on severe levels, DR reports. The organisation said the seabed at the two locations was like a desert.

The flags, which show a white fish, are intended as a warning that conditions beneath the fjords calm surface are unsafe for fish. Greenpeace campaign manager Emil Bejer-Pedersen compared them with the red flags lifeguards raise when it is too dangerous to swim.

Greenpeace and the Danish Sport Angling Association declared Vejle Fjord dead in a symbolic burial ceremony in April 2024. They returned on Wednesday to investigate whether the fjord showed signs of recovery.

However, data from eight monitoring stations that measure the fjords environmental condition every 10 minutes throughout the year present a more nuanced picture, according to Mogens Flindt, a biology professor at the University of Southern Denmark.

The inner fjord between Vejle Fjord Bridge and the city of Vejle frequently experiences oxygen depletion. Farther out, at depths of up to four or five metres, oxygen depletion is measured only in a few situations, Flindt said.

Those are also the areas where restoration work involving eelgrass, mussel beds and stone reefs is taking place. Flindt said the fjord is in better condition there than its reputation suggests, with biodiversity increasing as eelgrass has been planted over several years.

He described the restoration of Vejle Fjord as Denmark largest marine restoration project, while noting that the restored areas remain limited. Eelgrass cannot be planted at depths where light does not reach, and oxygen depletion occurs at depths of 10 metres, including in the outer fjord.

Greenpeace acknowledged that substantial restoration work is under way but said the goal should be to create conditions for life throughout the fjord, rather than only in isolated pockets.

Flindt said several other Danish fjords, including Haderslev Fjord, Flensburg Fjord and the Limfjord, have more severely depleted environmental conditions than Vejle Fjord.

Bejer-Pedersen said the comparison reflected the poor water quality in many other places and blamed large nitrogen discharges from industrial agriculture for the wider problem.