Sotka with the invasive species of seaweed.
It all started with Japanese oysters, World War II, and a species of seaweed on the lam.
At least that’s the working theory.
“After World War II, the U.S. asked Japan to send oysters to the west and east coasts of the United States and Europe,” College of Charleston Associate Professor of Biology Erik Sotka said. “We have these images of Japanese planes carrying tons of oysters and dumping them in the ocean around the U.S.”
Unfortunately the Japanese oysters weren’t cleaned prior to being shipped, and Sotka believes they may have accidentally taken an invasive seaweed species, Gracilaria vermiculophylla, with them.
Today, the invasive species can be found in virtually every estuary in the northern hemisphere. “It’s everywhere, from Pacific Canada to Mexico, from Maine to Georgia, Morocco to the Baltic Sea,” Sotka said. “You can’t walk through a mudflat in South Carolina without seeing it.”
The pervasiveness of this single species across so much of the world has mysterious evolutionary and historical causes. Sotka plans to start from the beginning with the help of his colleague adjunct facutly member and postdoctoral researcher Stacy A. Krueger-Hadfield, and a generous grant from the National Science Foundation (NSF) to research the evolutionary saga of G. vermiculophylla.
“We think that part of the reason this seaweed is so successful is that in parts of Asia seaweed was farmed for certain qualities. The people farming it probably selected traits that they wanted and bred for those traits – in this case, G. vermiculophylla was likely bred for resistance to environmental stressors, bacteria and being eaten. And then it escaped from the farm,” Sotka said.
That’s where the oysters come in.
“We’re going to use genetic tools, laboratory experiments and a lot of travel to reconstruct the evolutionary history,” Sotka said.
This NSF grant allows Sotka and Krueger-Hadfield to explore the evolutionary changes that contributed to this adaptive species’ development – the College’s Sotka Laboratory has already traced G. vermiculophylla to Japan, the first definitive discovery about where it originated. Additionally, through a NSF grant awarded in 2011, the Sotka Laboratory has been working to identify the positive and negative effects of G. vermiculophylla on preexisting ecosystems.
Through both grants, the Sotka Laboratory has mentored four undergraduate students, three graduate students and one high school senior from Academic Magnet High School in North Charleston, S.C.
The NSF grant of $622,923, will begin in March 1, 2014, and will send Sotka and Krueger-Hadfield to Japan, South Korea, the eastern and western coasts of the U.S., Portugal, France, and Germany to collect environmental data and G. vermiculophylla samples.
