Behind Anemone Lines


Melissa and I have dedicated many words to persuading you that marine biology isn’t all about jumping into warm clear water and looking at critters. However, sometimes, on very rare and special occasions, that is what we get to do.

Bonjour! The STARESO research station in Corsica.
Photo by Marion van Rijssel. 

Within three minutes of jumping into the water for the first time, I spotted this octopus!

The University of Groningen offers a course to marine biology masters students on Mediterranean rocky shore ecosystems. After some intensive study at home and in the classroom, my class packed our bags and headed off to the northwest coast of Corsica for two weeks. While there, we developed and carried out small research projects. 

My group designed a study to research the distribution and movement of sea anemones. Our overarching hypothesis was that interaction between individual anemones is a driving factor in how they are distributed in the environment.

Our target species was ideal: easy-to-spot coloration plus convenient location at the surface.
Maybe you don’t recognize these as anemones – they often keep their tentacles tucked inside.

Sea anemones are relatives of jellyfish, and just like jellies, anemones have stinging cells containing nematocysts, which they use for catching prey. But that’s not all: anemones including our research subject Actinia equina can be very aggressive and may also use their nematocysts to battle one another. (You can watch a video of anemones fighting here.) The title for this blog actually comes from published scientific research on this topic! (Ayre & Grosberg 2005)

We picked a study site and tracked the anemones’ arrangement to see if and how that changed over time. We also collected some for studies in the lab. We expected that anemones that were close together would move away from each other, possibly after displaying some competitive behavior.

Field data was collected by snorkeling, but we had the chance to go on a few recreational dives, too.
Here I am gearing up in my awesome borrowed (and oh-so-sexy) retro wetsuit.
Photo by Sandra Striegel.

Is it just me, or is this hermit crab the world’s cutest grumpy crustacean?
Photo by Nina Fieten.

When you’re investing money and effort in field work, it’s important to get as much data as possible in the time you have. Our free time was officially limited to just one day off, during which we took a road trip along the scenic mountainous coast, the perfect way to get a taste of the rest of the island. The rest of the time, we suited up twice a day and snorkeled out to our field site and daily replicated our lab experiment – or at least we tried to. As with all research there were some hiccups, from choppy water conditions to malfunctioning cameras. Troubleshooting is just part of the deal. We also kept busy with data entry and some analysis.

Of course, even strenuous days were joyful. When “work” is snorkeling, you know you’re living the good life! My worst real pain came from a (still relatively mild) encounter with a sea urchin, which I brushed with my hand. I’m glad I didn’t go in for a full high-five, because it turns out that urchin wasn’t my homie. It took a very painful hour for my brave and persistent friend to dig a number of wee 3mm spines out using a needle (tweezers don't work!). The last one festered out a week later.

Beautiful - BUT DEADLY. Dun dun dunnn...
Just kidding, this species will only do real damage if you're allergic!

I was stoked to stumble upon this minute yet vividly colored flatworm hiding in the algae
(near an almost-as-tiny nudibranch).

This being my first time in the Mediterranean Sea, I relished the clear water and unfamiliar species. Avid followers of the One World One Ocean Campaign will remember how much I love to find nudibranchs because they have cool “super powers.” Another special highlight was going out for a night snorkel and seeing a cuttlefish iridescing beautifully under the glow of our dive lights.

We successfully returned home with a truckload of data to report on. It turns out that part of our hypothesis was true: even though they look so sedentary (they are classified as sessile creatures after all), anemones do move. The distribution of the group that we tracked in the field changed a little bit each time we measured. Better yet, in the lab we could see an anemone move all the way across the tank within a day.

Schools of Chromis chromis were a common and lovely sight.
Photo by Marion van Rijssel. 

Undercover - er, underwater - blending in so I can take the anemone by surprise.

However, we were unable to confirm our hypothesis regarding interaction and competition. Anemones’ movement was not affected by whether or not they are near a neighbor anemone, and we never observed them acting aggressively by trying to sting one another.  Why? Maybe Bay of Calvi anemones are under less competitive stress than those in other locations or used in other studies. Maybe there are simply other factors that outweigh interaction, such as availability of food. As is often the case, we can speculate, but this brings up as many new questions as it answers old ones.

The view that greeted me every morning: Calvi, the city across the bay.
Photo by Marion van Rijssel.

My hopes to learn some French and challenge Melissa were, shall we say, dashed on the rocky shore (I mainly managed to say merci beaucoup repeatedly to the amazing institute chefs). Still, the course wasn't a total loss. This was an incredibly rewarding opportunity to gain experience conducting field work in an unfamiliar environment. It was also a milestone: I still have independent projects to do (so I'm not done yet!), but turning in my final report for this marked the end of my last Master course. And between the enriching research/travel experience, and the amazing classmates-turned-friends, an unforgettable final class it was!

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