Photograph by Paul Kay, Oxford Scientific, Photolibrary
Close-up of Teredo navalis shipworm.
Photograph courtesy Christin Appelqvist
Published January 19, 2010
The dreaded wood-eating shipworm is invading northern Europe's Baltic Sea. The animal threatens to munch through thousands of Viking vessels and other historic shipwrecks, scientists warn.
(Related: "51 Headless Vikings Found in English Execution Pit?")
The sea's cool, brackish waters have for centuries protected the wrecks from the wormlike mollusks. But now global warming is making the Baltic Sea (map) more comfortable for the critters, a new study speculates.
Shipworms, which can obliterate a wreck in ten years, have already attacked about a hundred sunken vessels dating back to the 13th century in Baltic waters off Germany, Denmark, and Sweden, reported study co-author Christin Appelqvist.
"Since 1990 there has been a big range expansion in the southern Baltic," said Appelqvist, a marine biologist at the University of Gothenburg in Sweden.
Until recently the wood-boring molluscs, which generally require relatively salty waters, were unable to survive in the low-salt Baltic.
Why shipworms are suddenly able to spread there remains a mystery, but studies suggest rising sea temperatures have something to do with it. In warmer water the animals, Appelqvist said, appear to be somehow "less stressed" by low salinity.
Global Worming Disaster?
The shipworm invasion could prove disastrous for marine archaeology in the region, home to long-submerged prehistoric timber settlements and remarkably preserved wrecks such as the salvaged 17th century Swedish warship the Vasa, a major museum attraction in Stockholm.
To defend the region's well-preserved wrecks from shipworms, researchers have suggested draping submerged vessels in polypropylene covers or covering ships with seabed sediments and sandbags.
Such a project could reach positively oceanic proportions, given that the Baltic holds about a hundred thousand well-preserved shipwrecks—and counting.
"Really nice tall ships with the mast and everything intact are still being discovered," Appelqvist said. "Every time [researchers] go down there with remotely operated vehicles they find new wrecks."
RELATED
Most Popular News
-
Pictures: Bird Mummies "Fed" After Death, Stuffed With Snails
Some of the millions of ancient Egyptian ibis mummies were "fed" after death, scans reveal—the better to live through the afterlife.
-
Lake Vostok Breached
Russian scientists have confirmed that they have breached the subglacial Lake Vostok in Antarctica—a first.
-
Oldest Animal Discovered?
Could 760-million-year-old African "sponges" be humankind's earliest known ancestors?
Advertisement
From the Web
-
From Huffington Post: Wolf Fosters Kitten
Adorable footage shows a pet wolf looking after a tiny kitty.
-
From Huffington Post: Rare Albino Hummingbird Spotted
The tiny bird was seen visiting a backyard in Virginia.
News Blogs
-
Texas Moves to Save Critical Groundwater
Ogallala Aquifer has dropped as much as 150 feet.
-
Good News, Bad News on U.S. Energy Outlook
The "all of the above" energy approach Obama championed in his State of the Union speech is at odds with U.S. climate goals.
-
Uranus Easy to Find This Week
Thanks to a close encounter with Venus, sky-watchers will have the chance the next few nights to easily glimpse the "green giant" Uranus.
ScienceBlogs Picks
Connect With Nat Geo
Got Something to Share?
Special Ad Section
Great Energy Challenge Blog
Green Living Hot Topics
-
Organic Air Fresheners
Avoid toxic chemicals and create a calming space.
-
Surprising Recyclable Household Items
With a little know-how, you can recycle more than you think.
-
Side Effects of Vegetarianism
Find out how to stay healthy and eat lower on the food chain.
