Sunken Munitions Unexpectedly Become Reefs: A Lesson on Nature, Humanity, and the Future of the Sea

In October 2024, researchers exploring the Lübeck Bay made an astonishing discovery on the floor of the Baltic Sea. They found dense, vibrant biological communities flourishing atop corroding World War II munitions.

What was originally engineered for mass destruction has fundamentally transformed into a structure that now supports thriving marine life. This unexpected finding quickly became the centerpiece of one of the most significant scientific revelations of 2025.

The War Debris Becomes a Marine Garden

Scientists affiliated with the Senckenberg Research Institute deployed a Remotely Operated Vehicle (ROV) to survey an area known for the dumping of old military ordnance. Their expectation was bleak: inert metal, toxic plumes, and biological emptiness.

Instead, the ROV transmitted images revealing an incredible density of life: over 40,000 organisms per square meter. This density rivals that of established coral reefs, significantly surpassing the biomass found on the surrounding seabed or natural muddy flats of the Baltic.

The reason for this concentration is rooted in the Baltic’s geology. The seafloor is predominantly soft silt, largely devoid of the hard substrates necessary for many species to anchor. Natural boulders were extensively removed through centuries of “stone fishing,” a practice that continued until 1976, effectively stripping the seabed of its architecture.

The iron casings of the wartime munitions—V-1 cruise missiles, artillery shells, and aerial bombs—provided the only hard surfaces available. The sea, indifferent to the metal’s origin, simply utilized this new foundation for biological colonization.

A New Substrate: The Scientific Explanation

The soft Baltic bottom lacks stable foundations because human activity, particularly the intensive stone dredging in the 19th and 20th centuries, removed most natural rock formations. When these metallic remnants of war settled, they offered a rare commodity: permanence.

These submerged casings immediately began serving functions they were never intended for. They became attachment points for mussels, platforms for sea stars, shelter for various fish species, and crucial habitat supporting the recovery of cod populations. Structure equates directly to life; the original purpose of the ordnance was entirely forgotten, leaving only its physical form behind.

Toxicity Exists, But Nature Exhibits Surprising Wisdom

Reports published in Communications Earth & Environment in September 2025 confirm that hazardous materials are present. TNT and RDX are leaching into the environment, and chemical signatures of the conflict are detectable nearby.

However, the most remarkable observation is that biological activity concentrates heavily on the external metal surfaces, actively avoiding the areas where the explosives are concentrated. The organisms are effectively sidestepping the toxic components.

This is not a desperate struggle; it is a clear demonstration of ecosystem self-regulation. Nature is applying an energy-based logic to classify space: this area offers support, while that area does not. It operates without human drama or moral judgment, simply following systemic imperatives.

1.6 Million Tons of Weaponry: A Legacy That Breathes

German territorial waters alone are estimated to hold approximately 1.6 million tons of legacy weaponry. It is now clear that a portion of this metallic past is actively contributing to a biological future.

Specifically in the research zone, ten V-1 flying bombs (Fi 103) from the Nazi era were identified. Devices once aimed at leveling cities now stand on the seabed, inadvertently fostering biodiversity.

Removal or Preservation? The Central Baltic Ecological Conflict

The imperative to clean the seabed for safety reasons—mitigating explosion risks and long-term contamination—remains paramount. Yet, removing the munitions means obliterating the established ecosystems that have taken root upon them.

This presents scientists with a profound dilemma: how can the sea be cleared of danger without destroying the life that has already sprung up from our debris? Germany has allocated 100 million euros for a pilot project addressing this very issue.

The proposed solution involves replacing the deteriorating munitions with purpose-built concrete reef structures. This strategy aims to preserve the existing biological matrix, eliminate explosive hazards, minimize toxicity risks, and secure the habitat for its current residents.

For the first time in decades, the discussion is shifting from merely removing the weapons to strategically and ecologically replacing them with structures that support life.

What the Baltic Sea Communicates—Philosophy Without Grandstanding

This narrative is not fundamentally about warfare or discarded metal. It is a stark illustration of nature’s operational philosophy:

• Where form exists, life will gather.

The Baltic Sea is achieving what humanity often fails to do. It transforms destruction into support. It accepts the metal of conflict but rejects its destructive intent. It proves that growth originates not from perfect conditions, but from whatever resources are immediately accessible.

Crucially, the sea reminds us that no place is truly dead as long as the potential for growth remains. Even the remnants of war can form the bedrock for a new future.