By Florian von Bechtolsheim and Anne Phillip, 2010 Summer Interns
“Anybody got some heavy-duty, double-zipper, sandwich-size Ziploc bags?” We had many such questions for everyone at SERC. We were known this summer as two students, looking for random stuff and entrenching ourselves in the wet lab. There was a reason for that.
We came from the Leibniz Institute of Marine Sciences in Kiel, Germany (IFM-GEOMAR) to study several globally invasive marine benthic species that threaten the world’s coasts. These organisms can have ecological and economic impacts. We wanted to know if stress resistance influenced their ability to become global invaders. Was there a difference in stress resistance between native and invasive populations of these species?
Our program, Global Approach by Modular Experiments (GAME), is the appropriate approach to try to answer such a question. By sending students to research stations in seven countries around the world, GAME provided the unique opportunity to study several invasive species in their respective native and invasive ranges simultaneously. Studying them at each research station according to the same experimental design and in the same lab environment, we produced results that are comparable across stations. Thanks to the strong support of our supervisor Joao Canning-Clode and SERC’s Marine Invasions Research Lab we were able to produce results.
We started our work in May, having a vague idea of how to proceed. We had to find our specimens, seal the lab, find tanks, airstones, tubing, Ziploc bags… Our original plan was to study four different species: Codium fragile, Ciona intestinalis, Perna viridis and Crepidula fornicata. Well, that was our wish. It turned out that Ciona intestinalis (a tunicate) was difficult to get and to transport, Codium fragile (a green alga) was just not feasible to study in a short time and Perna viridis (a bivalve) lost almost all its invasive population in the Gulf of Mexico. Crepidula fornicata, also known as the slipper limpet, was left, and thanks to Jim Carlton and Linsey Haram from Connecticut we got them to SERC in no time.
Slipper limpets are native in the intertidal and subtidal regions along most of the East Coast. The first invasion in Europe occurred in the late 1800s, followed by more recent invasions to Japan and the West Coast. Since then, they have spread, especially in Europe, where they are considered a threat to oyster production as they share the same space. Most probably they were introduced in the new habitats along with shipments of oysters (Crassostrea virginica).
We exposed a sample of the native population from the East Coast, as well as a sample from the invasive population on the West Coast to the same stress regimes. At the same time, our coworker in Wales conducted the same exact experiments, so we could compare one native population with samples of two different invasive sites.
Preliminary analysis showed that the invasive populations are more stress resistant than the native ones. But there are still a lot of analyses to be done, so it is possible that this statement could change. We will also have results from the other species which we can´t yet describe in detail (Crassostrea gigas, Codium fragile, Ciona intestinalis, Perna viridis).
By the end of the summer we found organisms to work with, figured out how to stress them and solved many problems along the way. We also ended up with quite a supply of Ziploc bags.