A Lake to Never Forget

During our ventures into the lake, we’d place 

Incubation rack floating in Anabaena

floating racks in the water to hang our bottles  on to incubate. The bottles were used to measure nitrogen fixation rates and metabolism. Since our species of focus, Anabaena, is pelagic and photosynthetic, we hang the bottles from the racks 0.5m below the surface to provide them a similar light and temperature to the environment where we have collected them from. There are clips used to hook the bottles on the rack and to do this, you have to lean over the side of the boat and reach your hand into the water. My hand got quite cold going between getting dunked into about 6ᵒC water and being out in the chilly wind. 

Cladophora growing at the bottom of the source river 
emptying into Myvatn

This task is both terrible due to the cold, but also surprisingly enjoyable. I was mainly surprised because of my previous hatred towards the cold back home in Minnesota. Though, Iceland is different somehow. I found the lake to be very mysterious. It is protected for research, so we are one of the few that get to be on it and it is such a privilege. So the moment my hand enters that water it is like I'm reaching into a different world. A world where organisms float through all depths of the lake, that interact not by speech or movement, but by the flow of nutrients and organic compounds, influenced by atomic charge and chemical gradients to form communities.

The days following this trip, I often think back to this experience. I know that this lake is only one of Earth’s various different ecosystems that is entirely natural and a piece of this unique planet, but I like to think of this experience as if for brief moments my body entered into a new world. This feeling and time spent on Myvatn will never be forgotten. It has opened my eyes to the beauty of nature and to the vast amount of knowledge that we have yet to uncover, inspiring future research. Out on the boat, I was often cold, tired and uncomfortable, but when we returned I always appreciated the experience and the hard work that we put into this research. I will always cherish my memories of Myvatn.

Myvatn sunset 

Boat Days

Hello everyone!

We have had several “boat days” as we call them since we’ve 

All of our field gear on the boat

been working in Myvatn. We LOVE  boat days, but the conditions have to be just right to be able to get out onto the lake and do our work. Most importantly, the wind speed needs to be between 0 and 5 m/s.  Any higher and the waves become too dangerous to navigate. So on those days, which there are a fair number of, we stay safe and warm in the lab processing samples that we have already collected in the field, running chemical analyses, analyzing data, and organizing (and drying out!) our field gear.

A typical boat day begins early in the morning because we are often trying to get all of our work done before the wind picks up or it starts to get too dark. Since we are working into late August, we have been able to watch the days get shorter and we no longer experience the midnight sun from mid-summer in Iceland.  It is getting really dark!But mornings are still bright very early. So first thing, we head to the research station to pick up all of our boxes and buckets and bottles and head out to the boat.

Boat Launch

When we reach boat launch, we place the boat in the water and then load our gear in. The water at boat launch often tells us how far we are going to have to go to find planktonic Anabaena that is dense enough for our experiments. If the water at boat launch is clear, then we will have to go further out into the lake to find the bloom, than if the water is green and full of Anabaena.

Sarah collecting water using a Schindler Trap 

An incubation rack holding tubes used for measuring metabolism

Once out on the lake, we collect water for our nitrogen fixation and metabolism incubations at a depth of 0.5-1.5 meters below the surface. Then if needed, we navigate to a clear spot in the lake, where light can penetrate the water to incubate our experiments. In our experiments, we vary the density of Anabaena, as well as light availability and the source of Anabaena within the lake.

                                  Boat days are long (and often cold) but they are always fun!

Sarah, Gabby and Jill on the boat! 

Catching the Bloom

Great day on the lake with Sarah Garcia, Gabby Holm,
Amanda McCormick, and Joe Phillips

Gabby taking gas samples

Much has happened since our last post.  Thanks to the generosity of Árni Einarsson at the Mývatn Research Station and the University of Wisconsin-Madison research crew, we have set up our gas chromatograph, learned how to navigate the lake and skipper the boat, and how to set up both sediment and pelagic incubations to make our measurements. It has been our first priority to catch the bloom of Anabaena that has covered the lake in recent weeks.  And, I am happy to report that we have successfully completed several sets of nitrogen fixation and metabolism measurements!  

Late night on the GC with Gabby

We are busy analyzing data now and preparing for our next few field days on the lake.  Days on the lake are dictated by the weather and while we can handle rain, high winds keep us off the lake and indoors, in the warm lab.  But, both field and lab days are important to accomplishing our work.  Blooms of Anabaena have regularly occurred in Mývatn; however, they may be becoming more frequent and extensive.  This year the bloom has been quite thick in some locations, blocking light from reaching the bottom.  Working with the team of researchers here, we want to understand how the cyanobacteria blooms influence the ecology of this amazing ecosystem.  We will have more to report as our project continues to develop.  Stay tuned…..

Sarah deploying our incubation tubes,
stocked with Anabaena, into the lake

Ocean Walk

While we were in Reykjavik we experienced one of sunniest days of the summer!

The weather here is normally cloudy and with periods of rain. Therefore, it was refreshing to see the sun and some bright blue sky. Since it was a wonderfully, glorious, bright, sunny day we finished work early and went out to explore the city and enjoy the sun.

I was able to take a long walk down a pathway by the ocean in Reykjavik. The ocean, a deep blue beauty, remains such a mystery to me no matter how much I learn about it. Along the path, there are a few spots where you can reach the water - one rocky and the other sandy. 

Listening to the sound of the water rolling over the shore and feeling the warmth of the bright sun beaming down, I couldn’t resist dipping my feet in the frigid cold water. 

This large rock on the beach had two distinct communities of organisms:

The limpet invasion 

and the slippery seaweed.

Be careful or they'll get you.....

Finally, at the end of the pathway, you reach a tiny yellow lighthouse, telling you that you've reached the outermost stretch of the peninsula that dips out into the sea.  And nice that it is easy to spot from all directions -  it is the color of rain boots. 

Bins, Boxes, and Buckets Oh My!

My name is Gabby Holm and I am a biology undergraduate at St. Catherine University. The past year I’ve been working to detect cyanotoxins with samples collected by Annette Benson Devine, who is a recent St.Kate's graduate that worked on the project last year. I am super excited to be in Iceland this year doing similar (and some new) work in Myvatn. This lake is very special because balls of green algae (called marimo in Japanese) form on the bottom of the lake.  The balls are comprised of Cladophora spp. along with a few other species that colonize the filaments of algae as it grows. 

Marimo green algae ball from Myvatn

However, there are also blooms of planktonic algae and in recent years, blooms of Anabaena have occurred, including this year - in fact, right at this moment! Our main goal is to measure the amount of nitrogen that is being fixed or brought into the lake from the atmosphere by this and other cyanobacteria. I will also continue my work on cyanotoxins and have the opportunity to collect samples of the Anabaena and other cyanobacteria and analyze them for a range of potential toxins.  This is important, as only some cyanobacteria produce toxins and little is known about the species found in Myvatn.  In order to do this work, we need a lot of equipment...

Microscope image of Anabaena 

Our supplies are kept at the Marine and Freshwater Research Institute in Reykjavik. Three giant pallets were taken off the shelf, and we had to look through everything.  Then, it was time to pack bins. This is the part of the trip where we get to find out how good we are at playing Tetris. I learned that Sarah was much better than me. I like to just squish supplies into bins, while Sarah actually organized the gear.

Equipment at the warehouse 

Since we needed a little bit of everything, including a gas chromatograph (which we use to measure nitrogen fixation), there was a lot of equipment. We ended up with 8 full bins. All of the bins were named by previous students and this makes each bin feel special. Bin Stitch I think must have anger issues because his lid will refuse to close. REX was taken out to the field everyday last year and so it has a special place in my heart. 

Bin REX and Batman

All of the bins were taken to the shipping company, and it was a great success that everything fit onto one pallet. They were then wrapped up, and in only two days they arrived in Myvatn.   Now we are ready to go!!

Bins at the shipping company