Dry It, Weigh It, Roll It: Dealing with Algae Outside of the Stream

The frantic pace of the summer has subsided (somewhat) and we are back to the stability of a weekly schedule. With classes well under way, multitasking is the name of the game when it comes to finishing homework and still moving forward with our research. It really makes us appreciate our summer abroad for the freedom from distraction it provided.

A dried, weighed, and rolled algae sample

            As Jill mentioned in the previous blog, we are processing the dried algal samples we collected over the summer. I have finished rolling samples to be run on the isotope ratio mass spectrometer (IRMS) to determine the ¹⁵N/¹⁴N ratios, as well as the overall carbon and nitrogen content within each algal sample. This was a tedious process that involved measuring out micrograms of algae into a small tin capsule – mere dust under normal circumstances, but powerful data in our hands. This will allow us to determine how much of our ¹⁵N₂ isotope got fixed and incorporated into biomass through the course of our field incubations in Iceland. Finally, we will get to see if this method worked like we thought it would.  Since we already have gas samples analyzed from the field, we know how much nitrogen fixation was occurring based on the acetylene reduction method. Comparing these results to the ¹⁵N isotope data will give us two measurements of nitrogen fixation rates and may help to illuminate the strengths and weaknesses of both methodologies.

Delor running a sample for P content

            In addition, I have been wrestling with another lab protocol that will tell us the phosphorus content in each of our algal samples. This has been challenging in the sense that we have to be sure that this method is giving us precise and accurate values. I have spent a great deal of of time practicing the techniques and various steps involved to ensure that we will be able to get the best results when we work with our actual samples.  Again, troubleshooting and problem-solving is key in our success – we need to intimately understand the protocols, equipment, and samples we are working with in order to achieve results that we can be confident in sharing with the world.

It has been interesting switching from large ecosystem scale field work to working with small scale microscopic lab procedures, like measuring nitrogen and phosphorus content in algae. Switching between moving big blobs of Nostoc around a stream to weighing miniscule amounts of powdered algae to determine their nutrient content presents its own challenges. The work is much more tedious and monotonous, but it still requires a high level of concentration to avoid sample contamination and ensure that the method works. It has been an exercise of both my patience and my chemistry techniques. I think I have found a balance between being so focused the work is frustrating and being absent-minded and making mistakes. I now look forward to my lab work as finals approach as a way to clear my mind in a more meditative fashion.

Delor pulling algal samples out of the muffle furnace for P analysis

   With Bayley’s presentation coming up we are beginning to meet our deadlines for this semester. We are all so proud of the work that we have done so far, and we are very excited to see how Bayley has synthesized our results and what she has to say about them! But this is by no means the end of our work, and there will be more to come next semester, including my upcoming presentation at the Society for Freshwater Science meeting!

             

Yes, We Are Still At It...And the Work Continues!

Life in the lab, packed with our Iceland containers and samples!

      We are hard at work in the lab this fall.  Delor has been spending most of her time preparing our dried algae samples for isotopic analysis.  This method will give us a second, and more direct, estimate of nitrogen fixation rates across the stream temperature gradient from the samples we collected in Iceland this summer.  I will let her update you more on that soon, but know that it is quite a time intensive process that requires Delor to mill each of the dried samples of algae into a fine powder and then weigh very small amounts of the powder into teeny tiny tin capsules before they can be run on the isotope ratio mass spectrometer to find out how much 14N and 15N (the two isotopes of nitrogen) they contain.   It it quite tedious and at the same time requires great attention to detail to make sure that the samples are carefully prepared and that the weights are accurately recorded.  She has milled and weighed more than 200 samples and we expect to have all of the isotope data sometime this coming week!  We are really excited to start analyzing them and begin exploring the patterns that emerge from the data.

Is it Anabaena or Anabaenopsis?  Turns out the
community is quite diverse,with a mix of these
cyanobacteria species and diatoms too!

      Bayley will be working with the data we will be getting this week as well, but her interest in the results focuses instead on the carbon and nitrogen content of the algae and how it changes across the temperature gradient.  She has been spending time reading up on the scientific literature that explores the concept of "ecological stoichiometry", or the carbon to nutrient ratios of organisms, the factors that can cause these ratios to vary, and why they are important.  She has also undertaken the tedious task of calculating the rock areas associated with the epilithic (attached to rocks) algal samples we collected this summer, which we will need to scale up our nitrogen fixation estimates  from our small chambers to whole streams.  Bayley will also be the first from our research team to present results in a public forum, as she will present the stoichiometry data in an oral presentation in the St. Catherine Biology Department Symposium in mid-December.  We are looking forward to her presentation and the story revealed by the results!

A sample that exhibits some of the amazing (and beautiful!)
diversity of nitrogen-fixers in our study streams.  Here we
see Anabaena spp. (the short chains of pearls) as well as
several diatom species (those with the intricate glass
cases) including Epithemia and Rhopalodia spp. with
cyanobacteria housed within
the diatoms themselves!   Photo by P.C. Furey

This is an image of Nostoc, one of the dominant
nitrogen-fixers, captured from one of our samples.
Photo by P.C. Furey

       

We are also very excited by our developing work with Dr. Paula Furey, a long-time collaborator of mine and colleague in the Biology Department.  Dr. Furey is an expert in algal identification and taxonomy and she is working to identify the incredible diversity of nitrogen-fixers in our Iceland samples that come into view under the microscope.  The images she is capturing are truly amazing and remind us that the plant diversity we see when looking at a tropical forest or native prairie ecosystem is certainly matched by algal and microbial species at the micro-scale.  It is neat to see the new images as they emerge each week in the lab and to think about these species in relation to the nitrogen fixation rates we have measured.   Given the species diversity, we want to know which ones are primarily responsible for the high nitrogen fixation rates we have observed.  Who is fixing all of that nitrogen?

The Trip is Over, But the Journey Has Just Begun

Jill and Bayley with some
of our lab luggage

A successful final field day
in the Hengill watershed

We’re now back in Minnesota, with fond memories of Iceland a part of us and lots of data processing ahead of us. We have accomplished so much over the summer and now comes the work of processing samples and working to synthesize the findings from our field research efforts. We will present our research findings in the coming year, both on campus, and at national scientific conferences. It will be great to show our fellow Katies how much potential they too have for accomplishing significant scientific research, even in a short period of time.  I am personally excited to be able to share my experience with others and I can't wait take this project to the next stage and broaden my skills further as I prepare for a conference presentation.

Delor getting ready for a field incubation, adding gas to
the syringe...

           We have already discussed several upcoming conferences that would be appropriate venues in which to share our research results including the American Society for Limnology and Oceanography (ASLO), as well as the Society for Freshwater Science (SFS), which will meet next spring.  Both conferences will attract aquatic ecologists from around the globe.  The Ecological Society of America (ESA) will also hold a meeting next August right here in the Twin Cities. This meeting will feature work from a variety of ecologists - freshwater, marine, and terrestrial, and provide an opportunity for us to make broader connections with scientists working across ecosystems.  We are also excited to reconnect with our Iceland collaborators as we prepare for and travel to conferences to share results from the full scale collaborative project, and to make connections with ecologists working on similar questions.   This is especially important for me while I am looking towards graduate programs after my graduation from St. Kate’s at the end of the coming year.

              I can’t wait to see what the next year has in store for me.  The possibilities seem endless and I am excited to see how the impact of this experience continues to grow as I explore the data and the implications of our findings.  I knew that an international research experience would be unlike anything I had ever done before, but I didn’t know just how much of a positive impact this experience would have on my future as a scientist, and my career direction. 

...adding water to the syringe...

                 For me, it was great to be able to focus on a research problem in an intensive way and to be able to put all of my creative energy and effort toward this problem.   From something as small as reading a scientific paper, to something as big as orchestrating field work, my self-confidence has sky rocketed.  Research is not mysterious anymore.  At its core, it is critical thought, which is empowering. We can all be invested in this process if we choose to be. I don’t have to trust someone else’s answers to these questions; I can address them myself.  I will read scientific papers in a whole new way now, knowing that the final product does not reflect all of the challenges and day-to-day changes that are an innate part of the research process.   This understanding is difficult to attain in a classroom setting.  You can only get it from an immersed experience that is so interconnected with a variety of research goals, while maintaining the focus required to complete a complex research project.

...capping a chamber...

        Our project was extremely important because we were working with a process that no one else was studying in the watershed – nitrogen fixation. Not only were we able to gather an unprecedented data set with riveting conclusions, we were also able to strengthen the work of our collaborators working within the same system. This was a great outcome of our work, showing us what team work is really all about.   I also learned that in the ecological sciences, no one person can do it all!  It was a great experience to be connected to a larger goal, and it challenged us to continually be thinking about the landscape as a whole.    We made a great contribution to a large research effort that will help complete our understanding of not only freshwater streams in Iceland, but how temperature affects freshwater ecosystems in general, and in turn how global warming may change our environment. 

...and adding gas-saturated water to a chamber with Jill

                I feel ready to take this project to the next stage, and I’m so excited to see what other opportunities will unfold throughout the course of the year. Hopefully we will be able to go back to Iceland and continue exploring new questions in the Hengill watershed next year.

The Sun Sets in Iceland

First summer sunset overlooking Reykjavik, just
outside the lab - we raced out to catch this photo.

Amazing how time flies!  When we arrived in Iceland at the beginning of July the sun was up most of the time, only setting for a few hours and the sunlight shined brightly through our windows in the late night hours.   It was exciting to see the activity in the city at night as Icelanders fully embraced the summer with outdoor concerts, festivals, gardening, and lots of spirit.  Our sleep cycles were certainly affected and it took some time to get used to sleeping when you should with the sunshine peeking through the blinds. We embraced the summer sun as well, appreciating the long days that allowed us to complete many field incubations in a single day, as they also depend on available light.  But, we learned too that the sun does set in Iceland and that you can’t readily incubate 20 chambers in a single day!  We did manage to do this once, but late into our overly ambitious day Bayley had to race the incubating chambers upstream to escape the growing shadow and shade that covered the lower portion of the stream as the sun began to duck behind the hillside.   The famous quote from that day was “twenty is too many”, and while we did it successfully, we all agreed that we shouldn’t embrace the illusion of a never ending day again. 

The group in Stokkseyri on the south coast of Iceland.  (right to left) Jim Hood,
Jon Olafsson, Jim Junker, Dan Nelson, Delor Sander,  Jill Welter,
Bayley Lawrence, (in front) Ryan McClure and Amanda Keasberry.

As the summer began to wind down, the days shortened quickly, almost as if overnight, with some of the most brilliant sunsets I have ever seen.  Maybe they were more spectacular because we hadn’t seen a full sunset in many weeks, or maybe the dramatic angle of the setting sun at our latitude made them more brilliant.  In either case, it was clear that summer was coming to an end and to the Icelanders that “winter is coming”, with short days, little sun, and still, lots of spirit and energy, and pride in the spectacular place that they live.    As the sun began to set, we also prepared to come home with a final celebration with our collaborators including students from Montana State University and the University of Alabama, Dr. Jim Hood (the project postdoc) and Dr. Jón Ólafsson from the Veiðimálastofnun (Iceland’s Institute for Freshwater Fisheries) and his family at Fjöruborðið in Stokkseyri on the South Coast of Iceland.  Fjöruborðið is renowned for its locally-sourced and homemade lobster soup, and it did not disappoint.  It was amazing and it was a wonderful time to celebrate the summer research accomplishments with our group.  We experienced the most beautiful drive down to the south coast, a wonderful exploration of the exposed tide pools, and yes, an amazing sunset.  

Our last sunset in Iceland - on the trip back from Stokkseyri.
A great end to a great summer!  photo by D. Sander.

The following day, the group began to head home, first with Dan and Amanda returning to Alabama, followed shortly by our group’s return to Minnesota, and finally the last group to Montana.   Amazingly, many in the group have connections to Minnesota, and we will see our collaborators here (likely at the Minnesota State Fair) and over the coming year at meetings and conferences.   I know that I have certainly developed a strong connection to Iceland, the people, the ecology, and the Hengill watershed, and it is hard to leave knowing that we have so much more to do and experience here.  It is a wonderful place!  But, while the sun is setting in Iceland and on our time in the Hengill streams for now, our work is really just beginning.  We have much sample processing and data analysis to complete in the coming year to finish our story and we are excited to see where this research will take us!  So, keep checking the blog for future updates.  Many thanks to all who helped to make this trip possible – it was all we imagined it would be and more!  And, we look forward to our future work on this project and hope to see more sunsets in Iceland as our research and collaboration develops!

Crunch Time...In So Many Ways!

Delor, Jill, and Bayley - last field day!

“Crunch time” represents our past few weeks in Iceland in numerous ways.  It has been time to focus intensively on our field work in an effort to complete our measurements on as many streams as possible before our departure, and time to crunch the data to begin to reveal what we have learned during our seven weeks here.   It has been too long since our last blog post, but we have been hard at work and things have been going very well.  But, very busy!  We have successfully measured nitrogen fixation rates on all of the dominant algal species (typically three or four different types, with 5-6 measurements for each species) on eight individual streams.  We also successfully used our two methods of measuring nitrogen fixation rates on almost all of these samples, which slowed down our progress across the landscape considerably, but we felt that this decision was a good one, as it will help us to evaluate these two methods and to better reveal to the field what each can tell us about nitrogen fixation measurements.  The data are also extremely exciting and a full data analysis indicates that nitrogen fixation rates in the warmest streams are an order of magnitude higher than the highest rates published in the stream scientific literature, which leads us to new questions about why rates are so high and what factors control nitrogen fixation rates in the Hengill streams.   We also observed high rates of nitrogen fixation rates at intermediate stream temperatures, while rates were extremely low and barely measureable in the coldest streams (~6 degrees Celsius).    We still have much work to do to fully complete our data analysis and to place these values into the context of the work of our collaborators here in Iceland, but it is certainly going to be exciting and very important for understanding how streams are responding to temperature across the landscape gradient.  There is also so much potential to expand the work we have started in ways that will contribute to our scientific understanding of the role that nitrogen fixation plays in river ecosystems, and how it influences the cycling of other biologically important elements, including carbon and phosphorus, and how these relationships are affected by changing temperature.

Delor and Jill with the gas chromatograph
in its new location.

While we started this work just a few months ago, we have learned a tremendous amount about these amazing rivers during our time here and everything has come together.  The gas chromatograph has run exceedingly well since its move to the new lab space, and we certainly feel that we have accomplished what we set out to do.  The diversity and complexity of the nitrogen-fixers that we encountered across the streams certainly kept us on our toes and required us to think creatively about how to approach our measurements every time we visited a new site.  It was not a “one approach fits all” situation, and we had to put our heads together every day to develop a plan that would capture nitrogen fixation rates in a rigorous and meaningful way.

Incredible day in the Hengill
fog and rain!

           The weather and the landscape also kept us vigilant, and at times storms kept us indoors when we wished we could continue our field survey.  During a day of record rain, we were able to visit the Hengill and watch our rivers flood, with spectacular waterfalls forming on the rocky hillsides, and the most beautiful fog drifting down and hugging the surrounding mountains.  It was one of our most incredible days in the field, despite the fact that the flood waters carried with it much of the nitrogen-fixers present in the rivers, whisking them downstream and possibly depositing them in nearby coastal and marine environments.    It was a strong reminder of the “reset button” that intense rainfall and episodic flooding provides in river ecosystems, and also got us thinking about the ultimate fate of the nitrogen that enters the rivers through nitrogen fixation – does it fuel more productivity and enter food webs that include insects and fish within rivers, as well as the surrounding terrestrial environment, or is it mostly deposited in marine areas where it may contribute to greater fertility and production there? And, does the fate of the nitrogen vary depending on the species of nitrogen-fixer and where it is located in the landscape?  These questions have important implications for understanding how this source of nitrogen is utilized in aquatic ecosystems, and how, where, and when it has important ecosystem consequences, and may provide future context for our work. 

Yes, it's a little windy and cold, but
just look at that view!  And, no black flies!

Of course, the intense precipitation also aggravated and activated the black flies, which came after us with a vengeance.  They were so intense that it was impossible to get photos that didn't have black flies on the camera lens, not to mention in your ears, eyes, and yes, in your mouth too.  While I suppose that I am not quite as excited about the black flies after this experience, they still did not detract from the wonder and beauty of this amazing place and all that we can learn here!  Going home will be bittersweet indeed, but at least our work is not done, and we will continue to analyze our samples and work with our Iceland collaborators to put the full story together.  We are very excited to see the complete results and to be able to share them and to begin looking toward the next chapter of this exciting project.


There's No "I" in "Team" - or in "Research"

Amanda Keasberry and Dan Nelson

from the University of Alabama

Here in Iceland, we have quickly realized how reliant research is upon teamwork. The project began as a collaborative effort starting with Dr. Wyatt Cross from Montana State University, and Dr. Jon Benstead and Dr. Alex Huryn from the University of Alabama. Many of the students' work here in Iceland is contingent upon a grant written by these three scientists to investigate the effect temperature is having upon the biology of these streams. While we are here, we are working side by side with two students from Montana State University - Jim Junker and Ryan McClure. Jim is a Ph.D. student in Dr. Cross’s lab working on his dissertation. Ryan is an undergraduate in ecology. He has developed a set of experiments with Dr. Cross to assess the effect of temperature and food quality on snail growth rates, with an emphasis on stoichiometry. We are also fortunate enough to work with two students from the University of Alabama - Ph.D. student Dan Nelson and Amanda Keasberry.  Amanda is an undergraduate student from the Aquatic Biology program who is quantifying invertebrate respiration rates across a temperature regime to help with Dan’s work and to develop a project of her own. We were able to have a round-table discussion about the details of our projects the other day, and it was fascinating to see the areas of overlap with everyone’s projects, and how we will be able to use each other’s data to further our own progress.  There has been talk of papers written by students from different universities - an amazing outcome from our efforts here that exemplifies the importance of teamwork and collaboration.

Ryan McClure (left) and Jim Junker (right)

from Montana State University

It has been a valuable experience as a budding scientist to get a taste for the rigorous requirements of a graduate program by working with Jim and Dan.  Often, they will be working before we get to the lab and will stay long after we leave for the day – I’m beginning to wonder if they ever sleep!  Dan and Jim have both chosen a heavy work load for their dissertations and they are working together in order to collect all of the data they will need to test their hypotheses.  They are even doing an experiment using a heat exchanger that will warm up one of the streams so they can directly see the impact of temperature on one particularstream community. By seeing their efforts, it has shown me the level of commitment you need to have to excel in the demanding field of ecosystem science, and also how collaborative the work is.

It is amazing to see how much drive and passion all of the students have for this area of work, and it inspires me to work even harder and to be a better scientist. I have come to realize through this experience that, even though we are all from different areas of the United States, these scientists are people just like me. It has been a great confidence boost knowing that I can fit in and be a valuable team member with a group that is accomplishing so many things from such diverse backgrounds. It has been enjoyable to see the impact of professors, postdoctoral researchers, Ph.D students, and undergraduates on a project, as well as how different universities can work together to achieve similar goals. The researchers at the Veiðimálastofnun, the lab where we are able to work, are very accommodating and help us find the space and resources we need to complete our work. Without them, it would be nearly impossible for us to accomplish this work, which will help with some research questions they have about the Hengill watershed as well.

(from left to right) Dan, Ryan, Bayley, Amanda,

and Jim enjoying  the scenery in Iceland

We are fortunate to be in contact with so many people who care so deeply about the questions that can be answered at this unique work site. It is a great introduction for me into the research field, as well as to ecosystem science. So far, it has been the experience of a lifetime - one that I could have only had working alongside new people in an environment that was foreign to me. It has made me push myself to try new things and ask more questions, and it has made me comfortable with many of the leadership responsibilities that come with being part of a research team. I am extremely grateful for the people who have helped to make this happen, and I can’t wait to pass on the experience and knowledge I will gain as part of this process to my classmates back at home. 

"I Love the Smell of Calcium Carbide in the Morning!"

Getting ready for chamber
incubations in the field

We successfully measured nitrogen fixation rates in the field last week using the acetylene reduction method.  It was great to be able to see our efforts come together and to be able to make actual measurements in the streams.  One of our methods utilizes calcium carbide to generate acetylene gas, which we collect in a balloon that we then pop to release the gas, after it has been sealed within our gas-tight chambers.  This technique allows us to measure nitrogen fixation rates because the of similar structure of atmospheric dinitrogen (N2) gas and acetylene, which "tricks" the nitrogenase enzyme into converting acetylene into ethylene.  After releasing the acetylene gas into the chambers, we collect gas samples over time and then measure their ethylene content on a gas chromatograph.  We then use the rate of ethylene production to estimate nitrogen fixation rates.  We had great fun generating acetylene gas in a side arm flask and filling a balloon with it.  Unfortunately, it was a little windy and rainy, making it challenging at times – something to get used to with the capricious weather in the Hengill watershed.   The calcium carbide has a unique smell (like old, sweaty gym socks, yuck!), which Bayley enjoyed, prompting the title to this blog entry.  After generating the acetylene, I got some practice collecting gas samples from the chambers, and more practice working with the gas chromatograph when we got back to the lab.  We also processed our algal samples from the chambers, and we will have some precise nitrogen fixation values to compare shortly.   The story behind each of the unique streams we are working with is just beginning to unfold.  The algal diversity between streams is striking and it’s clear at first glance that there are some distinct changes in species composition along the temperature gradient.  It seems like we have some powerful nitrogen fixers inhabiting the streams!  It has been great to get our field measurements going, as working with these methods out in the streams is different from doing them in a lab, and we are still a little clumsy, especially with the challenges presented by the constantly changing weather conditions.  It is very fulfilling to know that we are beginning to put all of our preparations into full use, and that the time we are spending troubleshooting will pay off in a tangible way very shortly.

Dr. Welter with a
chamber full of Anabaena

Me with incubating chambers

Chamber with
acetylene balloon

Positive Identification!

Enteromorpha inside a metabolism chamber

Dr. Welter and Dr. Jim Hood (the postdoctoral researcher running the field project here in Iceland as part of the U.S. team) took me and Delor out to the field to practice the chamber metabolism procedure and run through the field protocol step by step.  The field day was a practice run that would allow us to become familiar with the chambers, get an understanding for how the algae would respond to the chamber conditions, and to collect some samples to observe under the microscope for species identification.  The research team that we are collaborating with here has been placing tiles with attached algae inside the chambers, so the algae are largely stationary and fixed to the tile.  However, we are trying to place large flowing filaments of algae into the chambers and we discovered that there are a few complications.  There is a stir bar inside the chamber that keeps the water circulating, and we found that the algae gets caught as the bar rotates, which inhibits its purpose (see Delor’s Troubleshoot-ology blog as well for some details).  Since this discovery last week, Delor has been trying to create some sort of cage for the stir bar, so that it is able to circulate the water without interacting with the algae.  After trying several different size cages and mesh pouches, I think she has developed the perfect size to contain the stir bar and still allow water to flow!  We have tested it a few times under different conditions, and it seems to be working very well.

Nitrogen-fixing cyanobacteria under the microscope.
Photo by B. Lawrence

Using a survey of samples that we collected across all 13 streams, I have been doing my best to identify the different algal and cyanobacterial species.  Having never worked with algal species, the identification process was challenging.  When we were collecting the samples, Dr. Welter described and showed me the physical characteristics of different nitrogen-fixing species, like Nostoc, Anabaena, and Rivularia.  Having this background information was really helpful in the initial identification, but in order to more definitively classify them, I needed to look at the cells at a microscopic level.  For this, I have had the help of algal identification expert Dr. Paula Furey, a postdoctoral researcher working with Dr. Welter in her lab at St. Kate’s.  I also  studied several scientific journal articles and algal classification keys to give myself a good background and some valuable resources when looking at the species for the first time under the microscope.  Using these tools, I have positively identified nitrogen-fixers in our streams, including Nostoc, Anabaena, and Oscillatoria!!   

            We continued to venture out into the field this past week and I am also happy to report that we successfully measured nitrogen fixation rates.  We placed some of the dominant species from Stream 5 in chambers, collected gas and algal samples, and worked out the procedure for the new isotope method that we will be using in some of our nitrogen fixation surveys.  Delor ran the first set of gas samples, and we can positively say that there is indeed nitrogen fixation occurring in these streams, at what appears to be a high rate, even under the fairly common overcast conditions!! YAY!!  After looking at the samples under the microscope, I was fairly confident that we had identified nitrogen-fixers, but the gas readings have officially confirmed that they are fixing nitrogen gas from the atmosphere.  At first glance, it appears that Anabaena is fixing nitrogen at a much higher rate the Nostoc, but we need further sampling and some additional calculations to know for sure.   We plan to complete full surveys of nitrogen fixation rates in at least two more streams this week, so we will have more data to report soon! 

Troubleshoot-ology: The Study of Problem-Solving

 Bayley with the gas chromatograph and hydrogen generator

Troubleshooting, as we have quickly learned in our time in Iceland, is a very important part of research.  It is indeed a 'search' with many challenges that require innovation and creativity, and  we are continually thinking through the best way to approach our research questions and finding that we must modify equipment, invent new designs, and rethink our plans to best suit what we see in the field.  There are a myriad of variables to constantly consider, in addition to the unexpected things that can pop up at any moment.  We began our trip with power issues with a few essential pieces of equipment - the hydrogen generator and the gas chromatograph.  Once we were able to move into a different lab, we experienced some trouble getting the gas chromatograph to communicate with a computer. But, after reading and re-reading the fine print for our software driver installation, we were able to get the technology to work for us. We also went into the field with Dr. Jim Hood, the postdoctoral research associate in charge of the field project here in Iceland, to learn the particular methods that the group has been using to make metabolism measurements. It is important that we maintain as many methodological similarities across research teams as possible so we can effectively share the data we acquire. To make metabolism measurements for isolated stream substrates, the team is using large gas-tight Plexiglas chambers that seal at the base, with a hole on the top to accommodate a dissolved oxygen (DO) probe. This will allow us to measure the amount of oxygen that is being produced or consumed as a way of evaluating net respiration and photosynthetic rates by a variety of algal and cyanobacterial assemblages found across the study streams.

Dr. Jim Hood showing off the metabolism chamber

Dr. Jim Hood showing off the metabolism chamber

These chambers also use a magnetic fan and a stir bar to simulate water flow within the chambers and keep the water circulating throughout the metabolism incubation (another example of creative trouble shooting). This poses a problem with some of our algal samples however, as some species we have encountered are delicate and tend to float at the top of the chamber where the stir bar is spinning.  If the algae are disturbed too much, they may behave differently than they would in the stream. They may also be broken apart, which would potentially cause them to leak out nutrients, such as nitrogen and phosphorous, which we are planning to sample and evaluate in relation to metabolic rates.  The fans may also block some light. Yet, they do a good job of mimicking flow conditions in the stream, so this may present a light versus flow trade-off in terms of replicating natural conditions, and we will have to make some decisions about the magnitude of these trade-offs and what will be most important for our measurements.  At least the chambers maintain consistent conditions across sites and even if light is reduced somewhat, the chamber design will allow for valid comparisons among streams. We are considering modifying our own gas-tight chambers in order to be gentler on the algae. This comes with its own challenges, including modifying the openings to tightly fit the DO probe. This has been an interesting process as well because the materials we are used to working with back in the United States are not always available in Iceland. This has challenged our creative process and ingenuity, and our design has evolved to suit available materials, which has greatly improved our modifications.  
             There are always many things to consider when designing experimental methods, which is not always apparent within the context of a classroom or teaching lab.  It is amazing how much effort is put into studying complex ecosystems.  Every step needs to be carefully thought out, and even when you think you have everything figured out, new insights can throw you off course.  I have come to deeply appreciate the scientists before me that have developed the techniques we use frequently in the lab, as well as the professors who design experiments that work with time and resource restraints, while keeping the science exciting. It is amazing to be a part of this process to see how important team work and collaboration really is.  When one person has a moment of defeat, another team member can come in and save the day with an innovative idea. The challenges we are experiencing show just how perseverant and tenacious scientists are, and how rewarding it is to work through the trouble spots and find exciting and creative ways to answer our research questions.  I can't wait to see it all come together, and every day we are one step closer to answering our own questions about this complex watershed. 

All Systems Go - Gearing Up for a Big Field Week

Chambers for metabolism and nutrient uptake measurements.  
A dissolved oxygen probe records continuous changes in 
oxygen concentrations during light and dark incubation.

I am happy to report that the gas chromatograph is fully functional, the column heater is working great, and all of the instruments are operating well in their new location (new photos of our space to come soon!).  We have moved into a space in a genetics lab associated with the agricultural university here and we have met some really great people who are studying the evolutionary lineages and genetic history of wild strawberries as well as barley here in Iceland.  I know Delor in particular is excited to learn more about the molecular techniques that they are using in their work.  We were also in the field this past week, first to collect algal and cyanobacterial samples for further species identification under the microscope, which Bayley has been working on in the lab this week, and to begin our work with the sealed chambers that we will use to measure metabolic rates and nutrient uptake rates associated with different dominant algal assemblages.  We have been really lucky with the weather, but we did learn that even when it isn’t raining, it can be cold and the wind can be really strong….so strong that our equipment, including large storage containers, can blow away!  But it does have its advantages, as the wind takes the black flies with it as well, which does give you a break from the constant fluttering around your eyes, and we occasionally inhale one or two!  I don’t know about Bayley and Delor, but I will certainly tolerate these black flies over mosquitoes any day (there are no mosquitoes here in Iceland – very nice!)!   The flies aren’t so bad and if you keep moving, they do leave you alone.  We also learned that the chambers work really well for measuring metabolic rates, but they do present some challenges for working with fragile floating algal filaments and we are in creative invention mode right now, developing some new ideas and modifications that may work better for the species that we will be primarily studying.  We are gearing up for an intense field week and hope to have some nitrogen fixation rates from some of the warmer streams to report by week’s end.  Fingers crossed for good weather!  We have accomplished a great deal here and we are all excited to see our field planning come to fruition this week.

First Day in the Hengill

Hengill Power Plant - Geothermal source of energy in Iceland

As of July 6^th, the instruments were almost set up and the supplies that we ordered here had arrived, allowing us to hook up our carrier gas to the gas chromatograph. The hydrogen generator has been running well, which was a relief since we were nervous about the effect travel might have on it.  We have had a difficult time getting the gas chromatograph up and running, as it seems that the oven is not warming up.  We are hoping that this will be a simple fix.   We are trying to find a better location to set up the instrument to see if we are simply not drawing enough power in our current location and whether that could be contributing to our technical issues.  So, after brainstorming and trying several problem-solving approaches, we decided to take a break from the lab and we went out to the field in the afternoon to see the Hengill watershed for the first time.  It is absolutely beautiful!  The drive to get there is a little frightening, because the watershed is located behind the Hengill Power Plant, and we must drive off-road, around a mountain to get there.  But, it made the trip all the more exciting!  The purpose of the Hengill Power Plant is to meet the increasing demand for electricity and hot water for the Icelandic people.  It is the largest geothermal plant in Iceland and the second largest in the world.  Geothermal energy originates from the heat that is retained within the Earth and can be readily harnessed in areas with high tectonic and volcanic activity, like Iceland, where this heat source is close to the surface.  It is among one of the most cost effective heating and cooling energy source available today and is roughly 25-50% more efficient than traditional (fossil fuel based) heating methods. 

Hengill watershed - our study site

Before we headed for the Hengill watershed, Wyatt Cross, the lead U.S. scientist on this project (a professor at Montana State University), said, “It will be about a 20 minute drive to the site, and then there will be one difficult spot before we get to the streams.”  We all laughed thinking, how bad can it be?  We followed Dr. Cross to the site, and along the way about every two minutes we’d say, “do you think this is the spot he was talking about?”  Well, we said that about 8 times before actually arriving at THE spot where we were driving on the side of the mountain, almost parallel to the ground because the road is not filled in!  It was a little unsettling, but we made it just fine.  Whew!!  Dr. Welter is convinced that it will be an easy fix; all we have to do is get some shovels and fill it the spot with dirt and rocks.  It’s going to take a little elbow grease, but I have a feeling we will be fixing this spot in the road before the summer is over because she did not like driving over it yesterday.  

Dr. Welter holding Nostoc

The watershed is so vast; rocky mountainsides covered with moss and tundra grasses are visible in every direction among the streams that emerge from the hill slopes. We were able to drive close to research stream one, and we walked the rest of the way to see all 17 streams.  One of the many reasons this project is taking place in Iceland is due to the natural temperature gradient among the streams within the watershed.  We measure the water temperature in each stream to see the true variation and I was the temperature taker on Thursday.  Using a digital thermometer, I placed the reading end into the water and after a few seconds the temperature would stabilize, indicating the stream’s water temperature.  Not a challenging job, but very necessary and essential to our research.  Variation in temperature plays a role in the development of certain algal species and affects their growth rate, and we saw incredible variation in the abundance and diversity of species across the streams.  Each stream we observed looked completely different, not just because of location, temperature, and size, but the variation among algal species was incredible.  Dr. Welter was identifying Nostoc, Anabaena, and many other nitrogen fixers left and right; they are all over the place!  I am going to focus a majority of my time on identification of the different species and looking for growth patterns to better explain their variation across the watershed.  Upon first glance, it seems that the warmer streams contained more nitrogen fixers than the cooler streams.  I am excited to discover which species inhabit the streams and determine what other factors could be influencing the growth rates of the cyanobacteria in this amazing place!  

Environmental Consciousness: a Way of Life

Downtown Reykjavik

From the moment we set eyes upon Iceland it was clear that the people placed a high value upon the land that they live on. Just looking at the edge of the island from the plane, there was more vegetation than pavement. As we moved in closer to the landing strip, we could see clustered cities - even these views were intertwined with ribbons of foliage. We learned quickly that the geography of the land is tightly intertwined with everyday life in all places except for the busiest streets in the heart of the city. Even the town square in Reykjavík has a large patch of grass with chairs set out to lay in the sun for public use. Every front and back yard has splashes of color from rich flower beds planted along the edge of every property line. Our own flats at the University of Iceland have miniature green roofs on lower sections of the roof. The more suburban streets have beautiful rock fences low enough to the ground to accentuate the growth of bushes and flowers that spill into neighboring yards and walkways. In the layout of the city there is careful consideration to live with nature, not to cast it aside. This reflects the cultural attitude that seems always to be mindful of overarching environmental issues.

Our building, complete with a green roof

This eco-friendly mindset was apparent as soon as we got on the plane to head overseas. We were asked to save our beverage glasses if we requested a drink refill from the flight attendants to minimize our production of waste. Here in Iceland, customers in stores are always charged for plastic bags. Even though the charge is relatively minimal, it still is enough to encourage people to bring their own bags. Every time that we are checking out at a store, the cashier asks us if we really want a bag, as if the expectation is that we will not. To my surprise, a Simpson’s comic book I found at the grocery store even discussed environmental issues in the first few frames, with a concern for recycling old electronics. Even the washing machines are much smaller than the ones that we are used to, using less water per load of clothes. We also drive by a hydrogen fueling station daily, something we would never see in the United States. It is inspiring how committed Icelandic culture is to living with a minimal impact on their ecosystem. Though it is not perfect, it shows how well working together (and responsible environmental policies and cultural practices) can change the harmful effects that people can have on the world around them.