Nazi battleship's legacy stunts Norwegian trees

Nazi attempts to hide their largest warship in World War II continue to scar the Norwegian environment today.

The battleship Tirpitz was the biggest vessel in Hitler’s navy and spent much of the war along the coast of Norway to deter an Allied invasion and prey on Russian convoys.

In keeping with other Nazi weapons, it was built for shock and awe – spanning 250m in length and armed with eight fearsome 14-inch gun turrets.

But hiding the giant Tirpitz from Allied air attacks in Norwegian fjords was a big headache for the Germans.

In an effort to screen it when the warship was anchored at at Kåfjord in Norway’s west in 1944, the crew released chlorosulphuric acid to create an artificial fog.

Now after more than 70 years, the acid’s environmental damage is still being felt in the area, a study, presented to the European Geosciences Union in Austria on Wednesday, revealed.

Claudia Hartl, from the Johannes Gutenberg University in Germany, was studying the growth of pine trees in nearby Alta when she noticed something unusual: the older trees lacked growth rings.

Extreme cold or insect attack can impede the rings, but she knew of no natural effect that could halt a tree’s growth.

Some trees dated to 1945 – the end of World War II – had no rings at all.

After Hartl checked historical records, she found the Nazi sailors had released the acid.

"We think this artificial smoke damaged the needles on the trees," Dr Hartl told the BBC.

"If trees don't have needles they can't photosynthesise and they can't produce biomass.

“In pine trees, needles usually last from three to seven years because they're evergreens. So, if the trees lose their needles, it can take a very long time for them to recover."

An allied air attack on the Tirpitz while it was anchored at Kajford inflicted some damage on the battleship.

But a determined seek-and-destroy campaign by Britain’s Royal Air Force paid off months later when it was sunk by Lancaster bombers in late 1944 in Tromso fjord.