The Little Mermaid and the periwinkle: Research featured in a local Danish newspaper!

My past and present research were the focus of a story in a local Danish newspaper, written by my friend and colleague Dr. Bo Poulsen, Associate Professor at Aalborg University. It tells the story of the common periwinkle snail, Littorina littorea, and its journey from Europe to North America. See the Danish text below and then the Google Translator into English text below that. In the link here, the article can be found on page 16: ​http://www.e-pages.dk/ostvendsysselavis/397/

Amerikansk forsker på sneglejagt i Asa
Fra sin plads midt på havnen i Asaa sidder Den lille Havfrue på sin granitblok og holder øje med livet, der passerer forbi. På en solbeskinnet lørdag eftermiddag vrimler det med isspisende gæster, sultne måger på krabbejagt, og måske har en enkelt eventyrer på udkig efter sunkne naziskatte også fundet ud til kajkanten. Alligevel fik Den lille Havfrue noget nyt at kigge på Pinselørdag. Den berømte amerikanske biolog, Dr. April Houghton Blakeslee havde nemlig lagt vejen forbi Asaa på jagt efter snegle, nærmere bestemt almindelig strandsnegl.

April Blakeslee er en af Verdens førende eksperter i strandsnegle, og besøget på havnen i Asaa fandt sted som led i et storstilet nordatlantisk feltstudie af strandsneglen. Sin lidenhed til trods er strandsneglen nemlig meget udbredt på begge sider af Altanterhavet. I USA, hvor Blakeslee til daglig er lektor i biologi ved East Carolina University i North Carolina, finder man den almindelige strandsnegl i bælte langs østkysten ud mod Atlanterhavet. Langs Canadas atlanterhavskyst trives strandsneglen ligeledes, men ikke på Grønland, Island og Færøerne. På vores længdegrader i Nordeuropa er den lille snegl imidlertid helt almindeligt forekommende, således også i Kattegat.

Strandsneglen knytter sig tidligt i livet til en bestemt sten, hvor dens fod sætter sig fast, mens selve sneglehuset vokser sammen med de bløde dele. Særligt mobil er sneglen derfor ikke, så hvordan kan det være, at den findes på begge sider af Atlanterhavet, men ikke på øerne imellem? Lige præcis dette spørgsmål har Blakeslee undersøgt indgående de sidste 15 år: ”Sneglen er som mange andre dyr vært for en række parasitter, og i mit laboratorium har vi undersøgt forekomsten af parasitter i sneglen fra en lang række levesteder i både Nordamerika og Europa. Det gennemgående træk er, at der er langt færre forskellige parasitter, der er tilpasset til strandsneglene i Nordamerika, end i Europa. Det tyder på, at strandsneglen har eksisteret i Europa i meget længere tid end i Nordamerika. Den kommer altså oprindeligt fra Europa, og når den ikke findes på øerne i mellem, må det være mennesker, der har bragt strandsneglen til Amerika.”

April Blakeslee fortæller videre, at der er to teorier om, sneglen er kommet til Amerika. Det mest sandsynlige er, at der er sket i 1700-tallet, hvor der var en livlig skibstrafik med store sejlskibe tværs over Atlanterhavet. Som ballast fyldte man store sten i bunden af skibene, så de lå mere stabilt, hvis der ikke var så megen gods ombord. Store ballaststen, man kunne finde ved stranden er et perfekt levested for sneglen, og så kan man forestille sig, at sten er blevet smidt overbord igen i Amerika, hvis der ikke har været brug for lige så mange til turen tilbage til Europa. Den anden teori er, at det er vikingerne, der har hjulpet strandsneglen over Atlanterhavet. Man kan nemlig fint spise sneglene, hvis de bliver kogt først, så vikingerne kunne godt have haft de levende snegle med som proviant under sejlads fra for eksempel Grønland til det nuværende Canada.

Imod denne teori taler imidlertid, at strandsneglen, som nævnt ikke lever på de nordatlantiske øer i dag. Men spise dem, kan man fortsat. ”De lokale snegle jeg har fundet i Asaa og i Hals er ret store, og man kunne sagtens koge dem og spise dem,” udtaler Blakeslee. Hun er dog ikke interesseret i at stille sin sult med de nys indsamlede snegle. ”Nej”, siger hun, ”jeg har nok brugt for meget tid i laboratoriet på at studere de forskellige parasitter, der bor i sneglene, så jeg har mistet appetitten. Desuden skal jeg jo bruge sneglene til min forskning!”

Blakeslee kommer i bil fra Sverige, og hun er på gennemtræk i Østvendsyssel. Efter et kort besøg hos venner i Dronninglund, kører April Blakeslee da også videre til det hollandske havforskningscenter på øen Texel, hvor flere dages laboratoriearbejde venter forude. Blakeslee undersøger for tiden, hvordan de parasitter, der lever i sneglen, flytter videre til krabber, der spiser sneglene, mens havmågerne får besøg af parasitterne i et tredje livsstadium, når de sætter næbbet i en krabbe.

Asaa og Asaa Havn er et særligt sted fuld af gode historier, og nu er en ny føjet til i rækken: Asaa Havn spiller en vigtig rolle for forståelsen af, at strandsneglen oprindeligt er blevet flyttet fra Europa til Nordamerika – hvem ved, måske af vikinger med aner i Østvendsyssel. Den lille Havfrue i Asaa står midt i mellem store sten, hvor strandsneglene sidder tæt. Hvis havfruen kunne, ville hun som sin medsøster i H. C. Andersens eventyr nikke bekræftende; ”Det er ganske vist.”

English Translation (Google Translator-- with a few odd translations here and there!):

American researcher on snail hunt in Asa
From its place in the middle of the harbor of Asaa, The Little Mermaid is sitting on its granite block and watching the passing life. On a sunbreak on Saturday afternoon, it is abundant with ice-cream visitors, hungry crabs, and perhaps a single adventurer looking for sunken treasure also found out to the quayside. Nevertheless, the Little Mermaid got something new to look at on Pentecost. The famous American biologist, Dr. April Houghton Blakeslee had set the road past Asaa in search of snails, more specifically ordinary beach snails.

April Blakeslee is one of the world's leading beach snail experts, and the visit to the Asaa harbor took place as part of a large-scale North Atlantic field study of the periwinkle snail. Its slightness, though, is the beach snail is very common on both sides of the Atlantic Ocean. In the United States, where Blakeslee is a lecturer in biology at East Carolina University in North Carolina, one finds the common beach belt along the east coast towards the Atlantic Ocean. Along the Canadian coast of Canada thrives the snail, but not in Greenland, Iceland and the Faroe Islands. However, at our longitude in northern Europe, the small snail is quite common, so also in the Kattegat.

The beach snail ties in to the age of a certain rock where its foot gets stuck, while the snail's house grows with the soft parts. Especially mobile is not the snail, so how can it be found on both sides of the Atlantic, but not on the islands? Just this question, Blakeslee has examined in depth the last 15 years: "Like many other animals, the snail has a number of parasites, and in my lab we have investigated the presence of parasites in the snail from a wide variety of habitats in both North America and Europe. The overall feature is that there are far fewer parasites infecting the snails in North America than in Europe. This suggests that the periwinkle snail has existed in Europe for a much longer period than in North America. It originates from Europe, and when it is not found on the islands in between, there must be people who have brought it to America. "

April Blakeslee further states that there are two theories about the snail has come to America. The most likely is that in the 1700s, there was a lively ship traffic with large sailing ships across the Atlantic Ocean. As a ballast, large stones were filled at the bottom of the ships, so they were more stable if there was not so much goods aboard. Big ballast stones one could find at the beach is a perfect habitat for the snail, and one can imagine that stone has been thrown back in America if there has been no need for the same trip to Europe. The second theory is that it is the Vikings who have helped the Atlantic Ocean coastline. One can eat the snails if they are boiled first, so the Vikings could have had the live snails as a supply while sailing from, for example, Greenland to present Canada.
However, contrary to this theory, the periwinkle snail, as mentioned, does not live on the North Atlantic islands today. But eat them, you can continue to do. "The local snails I've found in Asaa and in Hals are quite big and you could cook them and eat them," Blakeslee says. However, she is not interested in letting her hunger with the newly collected snails. "No," she says, "I've probably spent too much time in the lab studying the different parasites that live in the snails, so I've lost the appetite. In addition, I'll use the snails for my research! "

Blakeslee arrives by car from Sweden, and she is on the way to Østvendsyssel. After a short visit to friends in Dronninglund, April Blakeslee also travels to the Dutch Marine Research Center on the island of Texel, where several days of laboratory work awaits. Blakeslee is currently investigating how the parasites living in the snail move on to crabs who eat the snails while the seagulls visit the parasites in a third life stage when they put the beak in a crab.

Asaa and Asaa Harbor is a special place full of good stories, and now a new one is added to the series: Asaa Harbor plays an important role in understanding that the periwinkle snail has originally been moved from Europe to North America - who knows maybe Vikings with ancestors in Østvendsyssel. The little mermaid in Asaa stands in the midst of large stones, where the strand nails are sealed. If the mermaid could, she would, as her fellow sister in H. C. Andersen's adventures, not confirm that: "It is true."