Underwater footage from Køge Bay reveals a dead seafloor caused by decades of sand extraction, but new reef projects are giving hope for the Danish marine environment.
Disturbing Discoveries Beneath the Surface
What looks peaceful from above hides a grim reality below. Marine biologist Sandra Helmark Hansen recently joined a small team on a boat in Køge Bay to investigate the state of the seabed. Accompanying her were environmental activist Jan Henningsen and Allan Scheller, chairman of the association Køge Bugt Stenrev. Using an underwater drone, they recorded images of what Hansen described as an almost “explosive mud cloud” each time the drone touched the bottom.
It quickly became clear how devastated the seabed had become. The footage showed lifeless silt and fine mud instead of plants, rocks, or sand. According to Hansen, the mud now floats freely because there is nothing left to hold it in place.
Years of Sand Extraction Have Destroyed the Bay Floor
The group had set out to examine parts of the bay where years of sand suction have wiped out the seabed. The process involves ships lowering huge hoses to vacuum sand from the seabed to supply construction materials. Once collected, the sand is transported for use on land. What remains underwater is a desolate plain completely stripped of its natural base.
Allan Scheller explained that every new drone dive in different areas of the bay shows the same lifeless mud. The scale of the damage is still not fully known, but the recurring pattern points to large stretches of dead seabed. The findings have reinforced worries already voiced by Danish scientists, who warn that industrial activity and seabed extraction are among the biggest threats to local ecosystems. Similar concerns also appear in the broader debate over trawling bans in Denmark, which aim to protect fragile marine habitats.
Efforts to Revive the Marine Environment
Despite the bleak images on the drone screen, there was still a glimmer of optimism onboard. Only a few miles away in the same bay, Scheller’s association recently built a new stone reef — one of several projects meant to restore underwater life.
Before Denmark banned stone fishing in 2009, more than 54 square kilometers of reefs had been removed from Danish waters, roughly the size of 7,500 soccer fields. Those reefs once served as breeding grounds for fish, shellfish, and marine vegetation. Without them, species diversity fell sharply.
Work on the new reef began just four months ago, and life is already returning. Drone footage now shows fish moving among the freshly placed stones. When two cod swam past the camera — a species that has become increasingly rare in Denmark’s coastal waters — the mood onboard improved instantly.
Signs of a Better Future
For years, environmental groups have pushed for tighter regulation of resource extraction in Danish waters. The Danish Environmental Protection Agency recently took a significant step by rejecting new sand extraction permits in southern Køge Bay, an area that had supplied sand to the construction sector for six decades.
These efforts, combined with new reef-building projects, signal gradual progress toward a healthier marine ecosystem. Conservationists stress, however, that changes must go further, from limiting future suction dredging to reinforcing habitat restoration on a larger scale.
Protecting marine areas has also become part of nationwide initiatives tied to sustainability and environmental insurance in Denmark, which helps foreign workers and companies take part in green transition efforts.
Even though the seabed in Køge Bay still shows clear signs of decades of exploitation, the discovery of living fish in the new reefs gives a reason to believe that the sea can recover when given the chance. It offers a small but meaningful reminder that Denmark’s coastal environment, once heavily altered by human activity, can slowly regain balance through careful protection and sustainable regulation.
Sources and References
The Danish Dream: Denmark bans trawling to protect Danish marine life
The Danish Dream: Best environmental insurance in Denmark for foreigners
TV2: Marinebiolog i chok over foruroligende billeder fra bugt
