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.

Wednesday, March 19, 2014

Lightening the Load


Rock covered in algae - all of which will be scraped off.
Then, the rock can be traced.
Even though we’re not in Iceland, we are hard at work here in Minnesota. For the last few weeks, I have been working on entering data into Microsoft Excel, and Aimee and I have been working with samples and data from the trip. As astute ecologists, we often wonder if we are measuring the most accurate number and getting accurate values for nitrogen fixation rates. Once we know how to make the measurements for nitrogen fixation, it becomes easy to slip into the habit of trusting the values we get from our data. However, being the perfectionists we are, we have learned otherwise. Our work is simply not done once we return from the field site, nor is it done after several days of lab work. Measuring nitrogen fixation, or any biological process, involves consistency in the field work and the lab work, and ensuring that we have all of the information we need to draw the right conclusions from our data.

Recently I have taken on the task of calculating the surface area of rocks that we pulled from the stream in January. When we were in Iceland, we took rocks from the stream, measured nitrogen fixation rates, and then scraped the algae off into a container and took the algae back to the lab. Later on, we would need to know the surface area that the algae inhabited on the rocks, but we didn’t want to carry around the rocks until we needed that information. To make our load a little lighter, we traced the rocks on waterproof paper and then labeled each side of the rock to help us know which sides were covered with the algae. This is like many of the first steps we take when dealing with field samples- transport. How do we get algae, rocks and water samples back home to our lab? Tasks like tracing rocks may seem arbitrary at the time, but it really simplifies our job down the road.

A photocopy of  a rock tracing - with all sides - that was
 traced in the field on January 15th, 2014.
Once we returned home, we were able to scan the rock tracings and load them onto our computers so we have a digital copy of the rock surface areas. However, these images don’t tell us the surface area of the rock on their own and it requires a little work on our part, more specifically on my part, to get the data. Over the last few weeks, I have been using a special computer program called Image J to find the area of the rock that we traced.  Precision is key here.   It is important that I carefully trace the images so that we obtain an accurate area of the rock. This also goes for any type of lab work that we do because without precision, we can't be sure if our calculated results are accurate or due to our own error in the methods.



Image J program - it is simply a tool bar on my desktop
and I open the rock files as photo images and trace them
with tools from this tool bar.
Even though the field work provides much better scenery, the lab work can be just as fun and exciting. Part of the experience of taking all these samples in Iceland is getting to see the final results come together. Sometimes the lab work can seem daunting and overwhelming even, but the end result is really worth it. It's been a fun process for me to see the follow through of a research project and how much work and dedication it can require. It has certainly given me a new perspective on ecological research. The next step in the process it to see the final work put together into a paper or presentation, where I will really get to see everything come together. 

Wednesday, March 5, 2014

Craft Time or Research?

Continuing on with my research, I’ve decided to design my own project this semester in hopes of answering some questions that came up during our trip to Iceland. I am interested in how nitrogen fixation rates have been measured in the field using different methods, and what each of those methods tells us. One of the most important parts of our research is making sure our methods are accurately measuring nitrogen fixation rates. If there are some variables that are unaccounted for in our methods, we may be underestimating or overestimating the rates at which new nitrogen is entering ecosystems.


One of the three methods - injecting the water with
heavy nitrogen gas.
This semester I will be working towards understanding how current methods for measuring nitrogen fixation rates compare to each other. I will be studying them in a completely controlled laboratory environment, while only manipulating single variables at a time. What I hope to establish is how each method responds to temperature when measuring nitrogen fixation rates. While not unexpected, the preliminary data suggest the three different methods that we have used in the field do not agree with each other. This is perplexing to me and I am determined to solve this mystery.


 Bauhaus - the "pot of gold" to us -
a hardware store we relied on in
Iceland for supplies.
As I prepare to begin my experiment, I have been reading scientific papers that describe these methods in detail, trying to understand long calculations, and thinking about all the details that I need to keep track of during my experiments. I have to closely monitor water temperature, pressure, and volume among many other variables. The next step will be to buy and order all the supplies I need, including live algal cultures, and make a trip to the local hardware store. It seems impossible, but sometimes we can’t just go online and order the exact supplies for these specific experiments. While they may not know it, hardware stores are very useful for scientific experiments.

Though it may not seem like it, research can involve many skills. It involves math, science, critical thinking and writing skills, just as much as it involves being just a little bit crafty at times. There are numerous occasions where we need to build custom supplies for such a specific task, that there just isn't the demand for them yet among many consumers, and they just can’t be ordered. The best way to get exactly what you want is to make it yourself. This requires some resourcefulness and thinking outside of the box. Luckily, hardware stores usually carry a wide variety of odds and ends to provide us with all the necessary items to make custom equipment that can suit the needs of any unique project. This is the part where I really have to thank my parents for all those years of childhood crafts and building projects. Those years of fine tuning my love and appreciation for tape, glue and re-purposed cardboard boxes have finally been put to the test and come in handy. Last summer our team invented a way to keep warm water in 60 ml syringes insulated while we shook them for 5 minutes or sometimes longer. What we came up with was insulating them with pipe insulation and duct tape. The design was nearly perfect - it allowed us to shake three large syringes in one hand at a time, while keeping the temperature of the water inside within a few tenths of a degree away from the temperature of the stream, after being exposed to the air for 5 minutes. This was especially ideal for days when the air temperature was much colder than the water temperature.
Syringe insulators made from pipe insulator and
wrapped in duct tape, which I named
"Sleevies", because they look like sleeves for syringes!

With my new project this semester, I will be using familiar methods, but I will be applying them in a laboratory setting.  So, I will have to rethink the overall design and discover how to best adapt our field methods for the lab. While working in the lab is certainly much easier than the unpredictable field environment in many ways, other aspects of the project become more challenging.  In the field, I really took for granted that the algae was right at our feet and self-sufficient -  all we had to do was collect it from the stream. Unfortunately, it is now winter in Minnesota and below freezing, and obtaining and maintaining algal specimens to work with will be one of the most challenging factors to deal with in a laboratory setting. Hopefully, I can find an algal species that will cooperate and be an appropriate comparison with our field data; however, I’m looking forward to the challenge.  I will really add some diversity to my skill set and research experience with this project, and will challenge myself in new ways by taking leadership of the project as a whole. Stay tuned for updates on my progress and possible inventions!