We are a group of freshwater ecologists from the Biology Department at St. Catherine University in Saint Paul, Minnesota. Our research takes us to Iceland and other arctic regions where we are working to understand how temperature influences nitrogen fixation rates and metabolism in cyanobacterial assemblages. Nitrogen fixation is extremely sensitive to temperature and therefore nitrogen gas from the atmosphere may become more accessible to freshwater ecosystems as the climate warms. We are working to understand the potential ecological and environmental implications of changes in cyanobacteria species composition and nitrogen fixation rates in arctic lakes and streams.
Thursday, September 19, 2013
10,000 New Ways to Think
Research is a process - it is about discoveries, about making mistakes, taking risks, trying new approaches, and sometimes starting over. We always learn from our mistakes and new approaches, gain some knowledge from the risks, and start over while remembering where we went astray. Thomas Edison once said about the process of inventing the light bulb, “I haven’t failed. I've just found 10,000 ways that don’t work.” This is the part of research that I love. I can go to work every day and not necessarily accomplish what I set out to do, but I will have learned something meaningful, even though it may not be what I expected. After days of preparation, packing, and test runs, you get up at 7 am, drive an hour to get to your field site, set up, and run an experiment, and the outcome may be totally unexpected; but, that doesn't mean that the day was a failure. In fact, through this process of trial and error, we find better and more efficient ways to make our measurements, and ultimately, the outcome and science is better for it! This process leads us to question our approaches and always be thinking about the unexpected. There are no rules for figuring out an answer, or guidebooks that will tell us in which direction to start. This is why research is such a creative process and requires a lot of flexibility and the ability to think in new ways.
One of the most rewarding experiences that I had this summer was the opportunity to design my own experiment and take charge of all of the details. Curiosity drives research, so I had to first ask myself, what am I curious about? After the course of a couple weeks in the field using three methods to measure nitrogen fixation, I asked myself, why can’t we use just one method, or what are the advantages and disadvantages of each method, and what can we understand better that will convince us of the accuracy of these methods? Then, I had to devise an array of field measurements using each of our methods that would provide some insight into where the discrepancies between the methods lies. The first day that I was in charge of the field team, I was running on adrenaline, not knowing what the results would reveal, or how the day would go.
I was counting and numbering vials, double-checking supplies, and packing extra everything, just in case. I was the one who had to delegate the tasks and provide the itinerary. I made some mistakes, and miscounted a few vials (which turned out to be a great learning experience in and of itself), but at the end of the day, it was a great success. I felt accomplished. We had new and novel data that will help us to better evaluate the methods for measuring nitrogen fixation, which will be an important contribution to the field. It was gratifying to complete a portion the large international collaborative project that I had designed. It gave me confidence in relying on myself and my own ideas, and brought even more questions to my attention that I hope to pursue in the future as I continue to do more research.
Friday, September 6, 2013
How Did It Get So Late So Soon?
Thumbs up for science! |
It’s hard to believe that we are
back in Minnesota already. I cannot believe how the time has
flown. It is great to be home, but I found myself having a hard time
leaving Iceland. There is so much left to do and experience! I look forward to
the day when I can return. The field days are over for now, but the fun in the
lab is just beginning. We were able to accomplish so much this summer and
I am looking forward to running samples, as well as analyzing and interpreting
the data this fall.
Four
months ago, I would have never dreamed that I would travel to another country
for the summer and be able to do cutting edge research with a gorgeous
backdrop. The days were long and sometimes the weather didn't cooperate,
but I never felt like I was going to work. I enjoyed the challenges that we
were faced with every day and the satisfaction that comes from knowing
that no matter the obstacle we faced, we were able to overcome it and find our
own creative solution.
One of the final times working with these chambers. Oh, how I miss them! |
Before this trip, I will admit that
I was hesitant and unsure about my abilities as a scientist. This
experience has given me the confidence to know that sometimes, more often than
not, something isn’t going to work, but I also know that I will figure out how
to make it work. Yes, that is the research process in action and I have a
much stronger understanding of the scientific process and the creativity and
trial and error involved.
Wednesday, July 24, 2013
The TriMethod Tournament
When using 3 methods to estimate nitrogen fixation, time and organization of the essence - and I made sure to keep us on task. |
Here, Jill and I are adding 15N2 gas (contained in the small gray cylinder) to our chambers containing algae from the different temperature treatments. |
It is definitely a coordinated team effort to get all of our various chambers set up and running - and in the rain!! |
It's working! Yes! |
So at the end of the day we had spent 10 hours in the field and we were exhausted, but excited to have completed an exceptionally successful day in the field. At the end of the day, I found it to be very satisfying to know that everything that we worked so hard on up to this day had paid off. And, just wait until you see the data - they are very exciting!! But, just like the journey of Harry Potter, not all can be revealed at once. You must wait until the full story unfolds...all in good time.
Sunday, July 21, 2013
Nitrogenase Activity and Temperature
While being here in Iceland, Jackie and I both have a great
opportunity to develop a research project. Over the past couple of weeks I have noticed
that particular species of nitrogen fixers are growing in select stream
temperatures. For example, “Rock” Nostoc
- Nostoc c.f. pruniforme (Kützing) Hariot, is only found in colder stream
temperatures, while “Pink” Nostoc, - Nostoc spongiaeforme Agardh ex
Born Flah, is found
in warmer streams. It was interesting to
see such a distinct species preference to temperature. I started to wonder what would happen to
these species if the stream temperature that they are acclimated to were to
change.
"Rock" Nostoc - Nostoc c.f. pruniforme |
In order to investigate this question, we will be doing a reciprocal transplant
experiment. We will collect dominant cyanobacteria (mostly Nostoc pruniforme)
found in cold streams (~10˚C) and transplant them into both colder (~5˚C),
warmer (15˚C), and hot (25˚C) streams. We will do the same for Pink Nostoc - Nostoc spongiaeforme,
whose resident mean stream
temperature is about 15˚C, as well as other dominant cyanobacteria species. By the end of the transplants, cyanobacteria
from each of their resident streams will be relocated to other streams spanning
this temperature gradient, with 5-6 replicates for each species. I know I
mentioned previously, that temperatures are increasing, so why put samples into
colder temperatures? Assuming
nitrogenase reacts to temperature like other enzymes, its activity rate should
decrease in colder temperatures and increase in warmer temperatures, up to some
threshold. Placing the dominant
cyanobacteria species across a wide temperature gradient and measuring their
nitrogen fixation rates will help us to better interpret and understand the
relationship between temperature and enzymatic activity and where and under
what conditions we should find each species.
"Pink" Nostoc - Nostoc spongiaeforme |
Sunday, July 7, 2013
"The" Number
We found algae! |
This summer we are planning to measure nitrogen fixation with three different approaches as a comparison of the methods, as well as to use them as a check against each other. For
Chemical conversion of nitrogen fixation (left) and how it compares to acetylene reduction (right). |
Working on getting "the" number. |
So far, our research has been really frustrating, impossibly complicated, and infinitely
Excited after a day in the field of hiking and looking at algae. |
Friday, July 5, 2013
"Re" Search
The last couple of
days have served as a great reminder that when a problem arises with a critical
part of an experiment, rarely is there a single solution. I thought that when an experiment was about to begin, all of the details were worked out, and the only tasks left were to collect data and analyze it. Wrong.
It has been said on several occasions that “once you smooth out the kinks, data
collection is a breeze”. Finding the kinks is easy; it’s the solution that’s
tricky.
The 300mL chamber that will be used to measure nitrogen fixation |
One of our methods
requires the use of an air-tight chamber. On the surface, it sounds like an easy
task. Only once you try to actually make a chamber air tight do you realize the
difficulty. In our collaboration with Tanner Williamson, we are using chambers that have been designed especially for this
experiment. These chambers hold only about 300 mL of water, which is ideal for
measuring biological processes on a small amount of algae. The small chamber volume is important
because the tiles that we are measuring nitrogen fixation on are barely a cubic
inch in size. The added bonus of these chambers is that it has a recirculating
fan that circulates the water within the chamber and mimic stream movement. The double-edged sword is that these
chambers only have one opening. The chambers that were used in our work last year had two openings; however, those chambers were much larger (2 liters) which
makes measuring nitrogen fixation more difficult. The benefit of having two
openings comes into play when we are required to simultaneously add gas and
remove water using two different ports. These new chambers posed two
problems: being air-tight and only having one opening.
Deciding to address
the gas-tight issue first, we attempted to cap the opening of the chamber with
a rubber septum. It turns out that this is extremely hard to do, as you are
essentially forcing an object against a positive pressure gradient.
Even though we managed to get the septum on, the chambers were over-pressurized and some airspace remained inside the chamber. Plan B involved a simpler method. Underwater there
should be no air, thus removing the problem of trapping air inside the chamber and over-pressurizing. Placing the septum over the top of the chamber while the septum and
chamber are submerged creates a chamber that is free of air.
Using a chamber with
only one opening has a few challenges within it. We are required to add gas and
remove water at the same time for one of our methods. This technique becomes
difficult to do when the only way into the chamber is through the septum at the
top (about the size of a quarter). Two insertions (one for the gas, the other for
the water) requires two people. We also have to insure that we are not pulling out the newly injected
gas as we are removing water from the chamber. We then had to address the issue of which insertion would work best for injecting the gas. In other words,
should we inject the gas at the top of the chamber or at the bottom? To answer
this, we added blue food coloring to the chamber, with the fan running, and
observed the flow pattern of the water. The food coloring instantly moves
toward the fan and begins to dilute. Based on this, we decided it would be most
beneficial to add the gas at the top of the chamber and pull the water out from
the bottom.
Several hours of critical thinking mixed with trial and error resulted in these problems being solved. At the end of the day, it is extremely gratifying to have created a solution to a problem that at the beginning of the day seemed unfix-able. These challenges have helped me to understand that critical thinking and creativity go hand in hand during research.
Several hours of critical thinking mixed with trial and error resulted in these problems being solved. At the end of the day, it is extremely gratifying to have created a solution to a problem that at the beginning of the day seemed unfix-able. These challenges have helped me to understand that critical thinking and creativity go hand in hand during research.
Tuesday, June 25, 2013
Latitude 66
Jill, Jackie, Aimee, Allison, Mara, Kyrstin & Anika |
Sunset over Greenland |
Since we have been here for several days now, I have had a chance to see more of the unique landscape of Iceland. The island is geologically young and was formed from volcanic eruptions from a giant volcanic hot spot that sits on the ridge of the Eurasian and American tectonic plates, which are constantly moving away from each other. This volcanic island has geothermally-heated pools and streams that are naturally warmed as water flows underground through heated rock, warming the water before it emerges at the ground surface. Iceland is also located close to the Arctic Circle, with the capitol Reykjavík positioned at a latitude of 66° north, where it does not get very warm, even during the summer. At this high latitude, Iceland experiences incredibly long days during the summer months and even though the sun sets for a couple hours, it never gets truly dark. This midnight sun allows the locals to take advantage of being outside as much as possible.
Iceland is certainly also a very unique place to study from an ecological standpoint. Since the island is so young, the volcanic basalt is very phosphorus-rich, suggesting that the growth of many organisms here is not limited by available phosphorus (an essential nutrient for growth), but instead constrained by a lack of available nitrogen – another essential nutrient. This provides a good environment for researching nitrogen fixers, which are bacteria that can acquire
Fields of lupine cover the hillslopes within the city and surrounding area, all along our drive to the field site. |
Monday, June 24, 2013
The "Less is More" Approach
The kitchen Jackie and I share |
Upon arriving in Iceland, one thing became
apparent immediately. Everything is much smaller. To an American, everything
about our apartment is compact and “fun size”. The bathroom appears to be built
inside of a storage closet, my bed is the size of a couch, and American hotel
rooms have bigger kitchens. We pride ourselves on our space; open living rooms
with hardly any furniture, king size beds, and large bathrooms. We,
unfortunately, disregard the impact these “necessities” have on our
environment.
Environmental impact is at the forefront of
Icelandic thought. This became clear very early in our travels. We were asked
to reuse our cups on the flight in an effort to reduce the amount of waste
produced. We learned that you will be charged if you need a bag to put
groceries in, which encourages people to reuse bags instead of throwing them
away. An average cup of coffee here is the same size as a small cup in the
U.S.
It is not difficult to get around Reykjavík by biking or walking, which helps reduce the amount of waste within the city. Even the garbage cans are smaller here, which helps you recognize just how much you are throwing away. It appears that the choice to be more efficient is collective in Iceland; it’s a way of life not a lifestyle. The idea of preserving the landscape and reducing environmental changes is deeply embedded in Icelandic society. It is a huge shock to be immersed in a culture where “less” does not mean less quality, it is simply less wasteful.
It is common to hear conversations about reducing waste and terrain conservation, but rarely do you hear about a place where these two ideas are actually carried out. Living in the United States, where the population is large, it can be difficult to believe that one person’s choice to be more eco-friendly will have an impact. It is wonderful to be in a country where this actually happens. Witnessing a country that successfully incorporates these two ideas into its society has changed my perspective on the likelihood that the same can be done holistically in the United States.
Friday, June 21, 2013
Field Work Begins with an Exciting Experiment
The 2013 field season has
officially begun for the St. Kate's crew. This year, we are working
closely with the Montana State team led by Tanner Williamson, a graduate
student who is conducting an elegant experiment that will assess the effect of
increasing temperature on algal species composition, biomass, and metabolism,
as well as nutrient content. Tanner has been in Iceland since early May
and has been working with the University of Alabama team (Phillip Johnson who designed and built the heat exchangers and Alex Huryn who designed and built the incubation chambers) to get this experiment
set up and operating well as the peak summer growing season approaches.
We will be working with Tanner to support his measurements and help out
wherever we can. We will also piggyback onto his data collection and
measure nitrogen fixation rates during each sampling period so that we can compare nitrogen fixation rates with
Tanner's estimates of photosynthesis and respiration across the temperature
gradient, as well as the uptake rate of essential nutrients from the stream
water, including nitrogen and phosphorus.
Experimental channels with 5 temperature treatments - ambient, +5, +10, +15, +20 degrees C. Three channels are maintained at each temperature. |
Close up of basalt tiles in the channels |
First field day measuring metabolic rates associated with algae and microbes that have colonized the tiles after 4 weeks. It was quite rainy and windy! |
We arrived just before the first sampling period, scheduled for 4 weeks after Tanner had placed clean basalt tiles into the channels to provide a colonization surface for the resident algae and microbial community. Upon inspection you could see that the tiles were beginning to turn green, with a visible effect of the temperature treatments, so it was time to collect the first initial set of data. Our first planned field day was canceled due to bad weather, which has to be pretty bad to cancel a field day (it was very foggy with low visibility and lots of rain), but we have been out in the field for the past 3 days now and we been fortunate to have sunny skies for the most part. The first day we measured photosynthesis and cellular respiration on sets of tiles from each of the experimental channels, followed by nutrient uptake (both nitrogen and phosphorus) yesterday and today. It has simply been beautiful out - so nice in fact, that one might be tempted to think that you no longer need to bring heavy rain gear to the field. Ah....but one should never give in to such thoughts at Hengill, as sunny skies can turn to cold wind and heavy rain in a blink of an eye!
Beautiful sunny day with
Ellie, Tanner, Jill, Aimee,
David and Jackie. Tile sampling, day 2.
|
Monday, June 17, 2013
We Have Arrived: Fixation on Ice Take Two - 2013
View of the edge of Greenland from the flight to Iceland. Photo by Jackie Goldschmidt. |
Yes - we have eagerly and successfully returned
to Iceland for Nitrogen Fixation on Ice Take Two! And, I am excited to
report that we arrived safely with our 14 checked containers (yes 14 this
year!) ready to hit the ground running. After a busy spring and recent
presentations of our work from last summer at the Society for Freshwater
Science conference (see posting below), we quickly packed up our gear with some
new supplies that will be part of an exciting and elaborate field experiment (more on that later this week). Aimee Ahles
and Jackie Goldschmidt, the two new SCU student participants for summer 2013,
did the bulk of the packing and organization and they were invaluable in
getting us ready for this year's research adventure. They will introduce
themselves and their experience so far in the coming days.
We departed at 7:30 pm on June 15th and arrived
yesterday at 6:30 am after a spectacular flight over northern Canada, across
Greenland, and into Iceland, ending with a smooth landing in Reykjavik.
The most difficult part of the trip was getting our 14 heavy containers
full of field and lab gear onto carts and out the doors through customs with
just the 3 of us to move it down the narrow corridor with its several sharp 90
degree turns on very little or no sleep. But, it
is hard to sleep when you are flying over such a breathtaking landscape.
It is almost hard to believe
it's real! And, the views are so
dynamic, changing minute by minute, it makes it nearly impossible to look away.
I was lucky enough to have a window seat on the north side of the plane
with the most amazing views from the edge of the planet at 37,000 feet - not to
mention the fact that as we near the longest day of the year in the northern
hemisphere - I was able to observe the longest sunset with the most beautiful
array of reds and oranges that saturated the clouds below us. The thick
cloud bank absorbed the color in a blanket of light as the sun sank further on
the horizon while the clouds dissipated over a period of an hour or so.
Then, just like that, the sun set....for about 15 minutes......and then the
sun began to rise and the colorful show played in reverse. It was simply
incredible. We were also fortunate that the clouds dissipated on the western
and eastern edges of Greenland, revealing the rugged mountains and massive
expanses of snow and ice, as well as the impressive chunks of floating ice in
the surrounding ocean water. Gratefully, Jackie took some great photos
from the south side of the plane as I sat in my seat many rows away, wishing
desperately that my camera wasn't tucked away in my bag! Never again!
Arrival at Keflavik Airport |
Jon Benstead (from the
University of Alabama) was nice enough to make the drive to Keflavik Airport
early in the morning to meet us with all of our gear and help us transport it
to the lab. I was also happy to see that I remembered the routes and
roads fairly well and we were able to navigate around the city with ease and
get settled into our housing after freeing ourselves from those 14 heavy
containers! Jon and his family (Heidi and daughter Lillian) also invited
the whole research crew over for dinner last night and we were treated a feast
of roasted lamb, potatoes, and wild mushrooms, followed by a Nerf (foam toy) gun target
competition, which apparently is becoming tradition at the Benstead household.
I am also proud to report that the SCU team performed exceptionally well
with no sleep and Aimee took first place - a high honor within this crew!
So, all in all, we are off to a great start and we are enjoying spending
some time with the team we will work with this summer, which is composed of
some returners from last year and some new participants. It is shaping up
to be a great summer!
Today was Independence Day in
Iceland and we enjoyed a great variety of games, plays, and music being
performed in downtown Reykjavik, and tomorrow our field work begins. We
leave for the field at 8 am, but we will have more blogs coming shortly, with
more details about our trip here, first impressions of Iceland, and our work
ahead. So, stay tuned! And, thank you, thank you to all of our
friends, family, esteemed alumnae and the St. Kate's community that have
supported us and made this trip and research project possible. We will
certainly make the most of this opportunity! Takk fyrir!
Society for Freshwater Science Conference in Florida
The St. Kate's Crew at the Society for Freshwater Science conference - left to right - Paula Furey, Delor Sander (standing), Jill Welter, and Anika Bratt |
Delor presenting her poster at SFS - pictured here with J.S. Ólafsson and G.M. Gíslason - our collaborators from Iceland, and Jim Hood from Montana State U. (left to right). |
Delor Sander et al. "Predicting effects of climate warming on N2-fixation and its ecological consequences in aquatic ecosystems: a comparison of acetylene reduction and 15N2 isotopic methods"
Jill Welter et al. - "Effect of temperature on N2-fixation rates and N2-fixer species assemblages in streams in the Hengill region of Iceland"
Paula Furey et al. - "Composition and abundance of nitrogen-fixing algal assemblages in nitrogen-limited streams along a geothermal gradient in the Hengill region of Iceland"
Jim Hood et al. - "Patterns of nitrogen and phosphorus uptake across a thermal gradient of subarctic streams"
Jim Junker et al. - "Patterns of epilithic CNP stoichiometry across a natural temperature gradient in Icelandic streams"
Dan Nelson et al. - "Experimental whole-stream warming increases algal standing crop but reduces consumer biomass"
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