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.

Monday, July 9, 2012

First Day in the Hengill

Hengill Power Plant - Geothermal source of energy in Iceland
As of July 6th, 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!  

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