The carcass of a 15-metre fin whale, stranded off the coast of the Danish island of Bornholm, has become a logistical and environmental test case. German authorities spent three days attempting to refloat the whale using inflatable pontoons and high-pressure water jets, a technique that has succeeded with smaller cetaceans. But the animal, weighing an estimated 25 tonnes, proved too large and too decomposed. The operation was suspended late Tuesday after the whale's body began to break apart under the strain.
Now a Danish team has taken over, using a different approach: towing the carcass to a remote location for natural decomposition. The plan involves attaching a buoy to the whale and pulling it with a patrol boat into deeper waters. It sounds simple, but it is not. A whale carcass at this stage of decay is a biological bomb. As bacteria consume the blubber, gases methane, hydrogen sulphide, and ammonia build up inside the body cavity. If the skin ruptures during towing, the release of these gases could be both hazardous and foul. The Danish Maritime Authority has issued a warning to shipping to stay clear.
This is not a unique event but a growing one. Fin whales, like all baleen whales, are indicators of ocean health. Their migration routes follow plankton blooms and krill concentrations, both of which are shifting due to rising sea temperatures. Strandings are increasing across the North Atlantic. The Scottish Marine Animal Stranding Scheme recorded 18 fin whale strandings in 2022, up from an average of seven. Each event raises the same question: was the animal sick, disoriented by underwater noise, or simply following food into shallows it could not navigate?
The German failed rescue is instructive. Modern cetacean rescue is a high-tech field involving sonar imaging of internal injuries, blood analysis for stress hormones, and careful flotation management. But it assumes the animal is alive and salvageable. In this case, post-mortem examination revealed the whale had been dead for at least a week before it drifted into the Baltic. The decomposition gases had already started to expand, making refloatation attempt likely to cause the carcass to burst.
Denmark's tow-and-leave strategy is pragmatic but carries its own risks. A whale carcass that sinks rapidly becomes a nutrient pulse for deep-sea scavengers, a natural part of the system. If it floats, it attracts seabirds and decomposes on the surface, potentially washing ashore elsewhere. The Danish team has chosen a site where the sea depth exceeds 200 metres, where the pressure will suppress methane release and the carcass will remain intact longer.
For the public, the spectacle is grim. But for scientists, each stranding is a dataset. Biopsy samples can reveal contaminants like PCBs and microplastics. Stable isotope analysis of the blubber can map the whale's feeding history over its entire lifespan. Even the decomposition rate, measured by time-lapse cameras on the sea floor, informs models of carbon cycling.
The tragedy here is not just the death of one whale. It is the slow accumulation of such deaths that tells the true story. Fin whales are classified as vulnerable, with an estimated global population of 100,000. They are not endangered, but their survival depends on an ocean that is becoming less predictable. The Baltic Sea, where this whale died, is one of the fastest-warming marine regions on Earth. Temperatures have risen by 1.5°C in the last 30 years. That shifts prey availability and disease resistance.
What the Danes are doing now is necessary. It is also a reminder that every dead whale is a monument to a changing world. As the tow rope goes taut, the real struggle is not with the weight of the corpse. It is with the forces driving the animal into our awareness in the first place.
