Pollutants from Old WWII Shipwrecks Are Poisoning the Environment, Posing Threats to Marine Life

Researchers have found that a World War II wreckage that is 80 years old still impacts the microbiology and geochemistry of the ocean floor where it is buried. Frontiers in Marine Science demonstrate how the wreck is seeping dangerous chemicals into the North Sea's ocean floor sediment, including explosives and heavy metals, which is changing the marine microbial community around it.

Contaminating the Sea

Several contaminants from a WWII wreckage have poured into the water, altering the ocean floor nearby.

Thousands of ship and aircraft wrecks, warfare chemicals, and tons of conventional weapons like shells and bombs are on the North Sea's seafloor. Hazardous materials in wrecks, such as explosives and gasoline, might endanger the maritime ecosystem. However, nothing is known about where the wrecks are and what impact they could have on the ecology.

Also Read: Finding the "Holy Grail" of Shipwrecks May Lead to More Deep-Sea Discoveries  

Interest in Shipwreck

According to Ph.D. candidate Josefien Van Landuyt of Ghent University, "the general public is frequently highly interested in shipwrecks because of their historical importance, but the potential environmental effect of these wrecks is generally disregarded."

For instance, it is believed that the total amount of petroleum products found in shipwrecks from World Wars I and II worldwide ranges from 2.5 million to 20.4 million tons.

Van Landuyt and her coworkers looked at the effects of the World War II wreckage V-1302 John Mahn on the microbiome and geochemistry of the surrounding seabed as part of the North Sea Wrecks project. The wreck is located in the Belgian portion of the North Sea.

This microbial investigation is unique within the research, according to Van Landuyt. "We wanted to investigate if historic shipwrecks in our area of the sea (Belgium) were still creating the local microbial populations and if they were still affecting the surrounding sediment."

During World War II, the German fishing trawler V-1302 John Mahn was commandeered and converted into a patrol vessel. It was bombed by the British Royal Air Force in front of the Belgian shore during "the Channel Dash" in 1942 when it swiftly sunk to the bottom of the water.

The scientists collected silt and steel hull samples from and around the wreckage at varying distances and orientations to studying the bio- and geochemistry in the area.

Depending on how far away from the wreckage, they discovered varying levels of harmful pollution concentrations. They most notably discovered explosive substances, polycyclic aromatic hydrocarbons (PAHs), arsenic, and heavy metals (including nickel and copper). PAHs are chemicals that naturally occur in coal, crude oil, and gasoline.

The sample closest to the ship's coal bunker had the greatest metal contents. In the wake of the wreck, newly deposited silt was heavily metalized. The areas nearest to the ship had the greatest PAH concentrations.

Van Landuyt said, "These old shipwrecks may still contaminate our marine ecology even if we don't see them, and many of us don't know where they are.

Still Affecting the Environment

As a result, their environmental effect is still developing. "Their rising age could enhance the environmental danger due to corrosion, opening up previously sealed places."

"People frequently forget that below the sea surface, we, as humans, have already made quite an impact on the local animals, microbes, and plants living there and are still making an impact, leaching chemicals, fossil fuels, and heavy metals from-sometimes century-old-wrecks we don't even remember being there," Van Landuyt said. "This study is only the tip of the iceberg."

Van Landuyt concluded that more shipwrecks in more areas would need to be sampled to acquire a more comprehensive picture of the overall effect of shipwrecks on the North Sea.

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