A large buoy that washed ashore on
the coast of Belgium in October – trailing a 10-foot rope that was covered in
hundreds of goose barnacles, crabs and shrimp – has been traced to an offshore
lobster boat based in Point Judith, R.I. The discovery of the buoy and attached marine
life illustrates one of many ways that non-native marine life finds its way to
distant shores. And one local scientist believes it’s a vector for invasive
species that will become more and more common as climate change produces increasingly
severe storms that will toss sturdy plastic debris into the ocean.
Aaron Fabrice, 20, who describes
himself as a beachcomber, citizen scientist, conservationist and nature guide, located
the buoy on a beach in the town of De Panne, on the northwest coast of Belgium,
on Oct. 8. He said the discovery was “like a dream” as he and a
friend counted
39 Columbus crabs, native to the Sargasso Sea near Bermuda, nestled between
hundreds of goose barnacles. He claims it is “the largest observed stranding
[of Columbus crabs] on the Belgian coast ever.”
Aaron Fabrice with buoy from Rhode Island found in Belgium (Diederick D'Hert) |
Fabrice also found numerous skeleton shrimp on
polyps on the barnacles, a species he said is commonly found attached to
floating debris.
After collecting samples of the crabs for the
Royal Belgian Institute for Natural Science, Fabrice posted photos of the buoy
to beachcombing and lobstering message boards showing the unique combination of
letters and numbers printed on it. Two months later, he learned that it
belonged to Rhode Island lobsterman Roy Campanale Jr. of Narragansett, who acknowledged
to Fabrice that he lost the buoy off his boat Mister Marco sometime in 2016.
“We did not expect that North American
floating objects would wash up on our coast,” wrote Fabrice in an email
message. “Normally floating objects from North America wash up in Cornwall,
U.K., or Brittany, France. There must have been an Atlantic seawater bubble
coming through the channel in the North Sea.”
According to Jim Carlton, an ecologist
at Williams College who studies marine invasive species, debris from North
America shows up on the coast of Europe fairly regularly, and it is often
colonized by a wide variety of marine life. He said that goose barnacles and
Columbus crabs are oceanic species that cannot live in the coastal zone, so they
are unlikely to become established in Belgium and affect native species.
But, he added, it could be that there
were species from North America that were buried within the barnacle-crab
community.
Carlton has studied the transoceanic
dispersal of marine life in great detail. Last fall he published a paper in the journal Science about the nearly 300
species of Asian marine life he and his colleagues found on debris along the U.S.
West Coast that they traced to the 2011 earthquake and tsunami in Japan.
He said that natural disaster provided
a greater opportunity for the dispersal of species across the Pacific than ever
before because of all the plastic objects that make up modern daily life.
Before plastic became ubiquitous, most storm-tossed marine debris consisted of
wood, vegetation and other biodegradable materials that would disintegrate
before it made it across the oceans.
“That got us thinking that the story of ocean
rafting has shifted rather remarkably in the last half century,” Carlton said.
“The plastic rafts at sea now are very enduring. They’re not degrading and
dissolving. Animals can go on a much longer voyage now than they could have
historically when they were drifting on a piece of vegetation.”
The implication is quite dramatic. Carlton believes
that the tsunami-caused invasion of species from across the Pacific is only a
hint of what is to come. As increasingly severe storms – the result of the
changing climate – hammer coastlines around the world, more and more marine
species will find their way across the oceans on plastic debris, ultimately
causing a homogenization of the world’s coastlines.
“Imagine the amount of debris that came off the
Caribbean islands during the hurricanes last fall – many hundreds if not
thousands of buildings and all of their contents were swept into the ocean,” he
said. “The climate models and evidence strongly suggest that we’re going to be
entering a world of more of these cyclonic systems, making ocean rafting
potentially one of the major new vectors for invasive species.”
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