Marine life is unexpectedly flourishing on discarded World War II munitions within the Baltic Sea.
A brand new research has discovered that World War II munitions mendacity on the seabed of the Baltic Sea host way more marine life than the encompassing sediment.
The analysis, revealed in Communications Earth & Environment, reveals that sure marine organisms can survive in areas with excessive ranges of poisonous compounds so long as they’ve strong surfaces to connect to. The findings additionally spotlight how remnants of human battle can unintentionally create habitats for wildlife, a sample additionally documented in a Scientific Data research that mapped World War I shipwrecks in Maryland, USA.
Before the 1972 London Convention on the Prevention of Marine Pollution was established, it was widespread observe to eliminate unused explosives by dumping them at sea. While these discarded weapons comprise chemical compounds which are extraordinarily dangerous to marine life, their sturdy steel shells might concurrently present an interesting floor for organisms to develop on.
Investigating the Lübeck Bay Dump Site
Andrey Vedenin and colleagues used a remotely managed submersible to analyze a newly-discovered munitions dumpsite in Lübeck Bay within the Baltic Sea in October 2024. They filmed the munitions and analyzed water samples collected from the location, and in addition investigated two areas of the encompassing sediment for comparability.
The authors recognized the discarded munitions as warheads from V-1 flying bombs, a sort of early cruise missile utilized by Nazi Germany in late World War II. They discovered that there was considerably extra marine life current on the munitions than the sediment — a median of round 43,000 organisms per sq. meter in comparison with round 8,200 organisms per sq. meter. Similar magnitudes of marine life abundance have been recorded on pure onerous surfaces within the bay in different research. The concentrations of explosive compounds (principally TNT and RDX) within the water various broadly, from as little as 30 nanograms per liter to as a lot as 2.7 milligrams per liter — a degree estimated to be probably fatally poisonous to marine life.
The authors counsel that, in comparison with the encompassing sediment, some great benefits of residing on the onerous surfaces of the munitions outweigh the disadvantages of the chemical publicity. They observe that organisms had been primarily noticed on the casings reasonably than uncovered explosive materials, and speculate that this may occasionally have mirrored lifeforms attempting to restrict their chemical publicity. However, the authors conclude that though the munitions are at present an essential habitat within the bay, changing them with a protected synthetic floor would additional profit the native ecosystem.
Ghost Fleet of Maryland: A Parallel Case
In a separate research, revealed in Scientific Data, David Johnston and colleagues current a high-resolution photographic map of all 147 wrecks at present within the so-called “Ghost Fleet” of Mallows Bay, on the Potomac River, Maryland, USA.
These ships had been constructed throughout World War I however had been intentionally burnt and sunk within the late Twenties, and their wrecks are actually referred to as a habitat for all kinds of wildlife, resembling ospreys (Pandion haliaetus) and Atlantic sturgeon (Acipenser oxyrinchus). The authors created the map by combining high-resolution images (a median of three.5 centimeters per pixel) of the complete fleet, taken utilizing aerial drones in 2016. They counsel that the map could also be helpful for future archaeological, ecological, and cultural analysis into the fleet.
Reference: “Sea-dumped munitions in the Baltic Sea support high epifauna abundance and diversity” 25 September 2025, Communications Earth & Environment.
DOI: 10.1038/s43247-025-02593-7
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