International Science and the lovely Stofan Cafe in downtown Reykjavik

It's rare that we get the opportunity to work closely with so many talented students and scientists (and student scientists!) from around the world. Our Hengill research is making this a reality. Here is a great shot of MOST of our broader team this summer (with the exception of Jill Welter and Jon Benstead, standing behind the lens - and the rest of the Alabama crew back in Tuscaloosa [Alex and Phillip]) at the Stofan Cafe.

Lots of representation here - Ireland, England, USA, Germany, and Canada. Cheers to many more great times!!  . . and may most of our paychecks continue to support the Icelandic cafes!!

Cheers!  Skál!

15N isotope releases completed successfully (woot woot!)

As previous posts have made clear, it was a slow and difficult start to the summer because of the weather, as well as problems getting the stream-side channels set up. The channels are now looking great but it all compounded to push the start of the planned 15N releases back by a few days. When we were finally ready, the weather did not look good. Finally, it looked like the rain might clear up, so we took the plunge - and it stayed dry for the entire 5-day period! Phew. The four simultaneous drips into streams 6, 9, 11 Upper and 18 and all the sampling went off without a hitch and the team just completed the first post-drip sampling. We're really excited to see where the 15N has ended up and where it will go over the summer. Watch this space.

Here are the pumps in the four streams, going from coldest (~5C) to warmest (~13C).

Three dweebs

Jon, Wyatt and Jill looking very proud of their Icelandic sweaters. Wonder how many team members wearing "lopapeysur" we can get in a picture...

The Hengill Landscape, According to Hilary

Hengill is a land of the sublime in every sense of the word. During the height of the Romantic period, artists across Europe and America were painting landscape works of art to show the awesome power of the landscape and humanity’s submission to the will of nature. Depictions of towering mountains or dramatic lighting across the plains add to the sublimity. All of this was to contrast with the familiar in pastoral works depicting rural communities or familiar places. In the case of Hengill, the sublime is apparent in the harsh conditions and the volcanic activity.

Boiling hot springs and warm, steaming fumaroles (that’s where much of the rotten eggs smell comes from), and recent lava fields across Hengill are just a few of the traits that show the environment’s power and might. The volcanic center of the earth is literally shaping the environment in new and majestic ways.

Furthermore, the dramatic lighting of a sublime scene inspires terror and awe in the viewer. Iceland has lighting in spades. While we are here in the summer it never truly darkens which could give the illusion of a friendly environment. But the midnight sun illuminates the volcanoes on the horizon and the jagged rocks formed when a volcano erupted under a glacier holding all the ash underneath. Some of the landscape may be covered with soils and mosses, but the volcanic origin of the island reawakens the memory of Mount Eyjafjallajokull which shut down air traffic in the whole region, far beyond the boundaries of Iceland.

But that’s all at the macro scale. What about the microscale sublimity? Just think about the diversity of organisms that exist in Hengill streams. We are capitalizing on the wide temperature gradient of streams to look at the diversity of organisms from bacterial to bugs but it’s incredible to think about the diversity that separates streams that distinguishable by temperature variation alone. Then there are also the various bacterial communities using sulfur as an energy source instead of photosynthesizing like plants. That’s a completely different energetic pathway compared to everything that grew to make your salad!

I love the romantic perspective, but in our modern age there are emerging post-romantic and the technological sublime. Now is there a way we can quantify the sublimity of nature? We are doing our best, looking at stoichiometry, nutrient cycling, populations, and communities in these streams to see if we can predict into the future what the fate of streams may be in the event of changing temperatures. In the meantime, I believe it’s pretty sublime to be invited out to Iceland to partake in a small share of investigating the Hengill streams.

The big heat exchanger gets spruced up

The heat exchanger that we've been using to heat Stream 7 since 2011 got a little banged up over the winter. It was time to haul it out and re-build it. Yesterday, five members of the team (Hilary Madinger, Bailey Kimbel, Luke Ginger, Wyatt Cross and Jon Benstead) stripped it down, cleaned off the impressive biofouling of mosses and filamentous algae, re-built it with new couplers and clamps, and plumbed it back into warm Stream 8 (with the help of Eoin O'Gorman and Bruno Gallo from the London team). All in one afternoon. Not bad.

The heat exchanger looked a little sad the day we pulled it out. Alternatively, it looked a lot like an art installation on the hillside. Here's the stream ecologist that fell to Earth...

Here are a few shots of the team re-building the heat exchanger yesterday. Left to right are Wyatt, Luke, Bailey and Hilary.

All put back together again.

The heat exchanger back in place and flowing again, with Wyatt making an ill-informed bid for a place in the 'Studmuffins of Science' calendar. Mr June, anyone?

So our fingers are crossed that the heat exchanger is good for a bit longer. We're now in our fifth year of warming and trying to keep it going a couple more years.

Cast of Summer 2015

With a new project comes a new cast of students and technicians! Here's a brief introduction to some of the new faces around Hengill this summer.

Abbi White is a junior at St. Catherine University in St. Paul, Minnesota majoring in Biology. She is interested in understanding the ecological stoichiometry of primary producers in streams. This is also Abbi’s first time doing field research.

Bailey Kimbel is joining us from Alabama and will be working as a research technician this summer. Originally from Minnesota, she graduated from the University of Minnesota in 2013 with a bachelor’s degree in Ecology, Evolution, and Behavior. She has aided in various ecological research projects from wheat disease studies to plant evolution.  Her positions have also brought her into the field, working in Western Wyoming and Costa Rica.  After spending a year taking care of cats and dogs as a veterinary technician, Bailey is thrilled for the opportunity to return to the research world with the Hengill team. While she is new to stream ecology research, she is more than ready to immerse herself in the intricacies of the field and excited to see what will be revealed while performing this research.



Bree Vculek is an undergraduate student studying biology and chemistry at St. Catherine University in St. Paul, MN. She joined the Welter lab as a research collaborator in 2014, and is interested in the physiological responses of nitrogen fixing cyanobacteria across temperature and nutrient gradients in stream ecosystems.








Delor Sander is from St. Catherine University (SCU) in Minnesota and is working as a lab and field technician for Dr. Jill Welter. As an undergraduate student at SCU, Delor spent the summer of 2012 working in Hengill and is back for a second summer to help collect and process samples. She is interested in continuing her career in science through a journalistic perspective and will be going to graduate school for Scientific Communication – if she doesn’t end up staying in Iceland after the project is over!

Hilary Madinger is a Ph.D. student at the University of Wyoming with work related to the Hengill crew’s biogeochemical investigation of nutrient cycling and especially nitrogen fixation. She will be assisting with the measurements of stream nutrient uptake and denitrification during the stable isotope addition. Additionally, Hilary will estimate diel nitrogen fixation fluxes in a few of the warm streams with low gas exchange. Then the rest of the summer will be spent running isotope samples and modeling the data collected in Hengill streams.

Kate Henderson is starting her Ph.D. research under Wyatt this summer, looking at the effects of warming and nutrient enrichment on secondary production. She just finished her M.S. in Biology from Tennessee Tech University, where she studied drivers of algal productivity in agriculturally managed lakes. Before grad school she worked as a field technician in Mexico and interned with a study abroad program in Costa Rica. At some point, she's hoping to ride an Icelandic horse.

Luke Ginger is an ecologist from Chicago working as a field tech for Wyatt Cross this summer. He did his undergraduate at the University of St. Thomas (2012), and received a master’s in Biology from Miami University (2014) where he worked with Mike Vanni. He is interested in the different variables driving N:P in aquatic ecosystems from agricultural activity to fish excretions. Outside of ecology, he is interested in playing music and travelling. 

Channel Experiments Start

We finally got the channel experiments started on Thursday! Delor and I celebrating after finally getting everything going around 10 PM:

Here's a diagram of the channel experiment and the heat exchanger (HEX) system that delivers warmed water to the channels.

Setting up this experiment has been a challenge which required the dedicated efforts of nearly a dozen people. Here are some photos celebrating our recent efforts since my last blog post.

Bree, Abbi, and Luke sorting nearly 2000 tiles into three size classes. They made a game out of it. The basalt tiles we purchased come in different heights. That might look great in a bathroom, but its not ideal for experimental channels.

Bree carrying a sandbag down to the channels to secure the dripper system. Bri, Abby, Delor, and I carried six of these things nearly 900 meters...

We have to regularly (every two to four days) measure and adjust the amount of water going through both the channels and the dripper system. Here, Delor is measuring the amount of water traveling through channels (i.e., the discharge).

Jon wrestling with the dripper tubing...

At the end of the channels, we installed something called nutrient diffusing substrates (NDS). They are used to measure how the degree of phosphorus limitation (whether biofilm growth responds to phosphorus fertilization) changes with temperature and nitrogen enrichment. The NDS's have glass frits on the top that are colonized by biofilm over the course of the experiment. The vials are filled with inert glass beads up until a couple of weeks before sampling when they are filled with agar (control treatment) and agar + phosphate (phosphorus treatment). I think this is the prettiest part of this experiment.

In this time lapse, you can see Jon and I plumbing the inlets and dealing with a burst fitting. The clouds are the coolest part.

Coming together. . .

It's been quite a busy week since the last post, and things are starting to look up. We've managed to successfully deliver water from the source stream to the heat exchangers, into header tanks, and onto our 30 experimental channels. We've also set up the nutrient dripping apparatus that will deliver micro-amounts of nitrogen to the channels. If all goes according to plan, we will have 5 temperature treatments, each with 6 levels of nitrogen enrichment - allowing us to produce fancy 'response surfaces' that characterize true interactions between temperature and nitrogen.  Pretty exciting stuff.

Jim Hood deserves some serious cred here for his tireless work to get this beast up and running.

A view of the heat exchanger battleships near the warmish pond

Water of varying temperatures heading toward the header tanks

Jon Benstead and Jim Hood lowering the ultra-heat exchanger into the hot pot

The beginning of experimental channel assembly

The nutrient dripping apparatus

Stay tuned for more news. . . . . and introductions from the rest of the team that just arrived!!!