Saturday, May 27, 2017

2017 Channel Experiment Begins!

After nearly 3 weeks of setup and countless trips carrying equipment to our field site, the big day has finally arrived- the channel experiment has officially begun! The temperature treatments are maintaining nice 4C intervals, the water flow through the channels is consistent, and the nutrient drippers are delivering a steady supply of N and P to each channel. Now I just get to sit back, relax, and let my biofilm grow. :)

Here's a picture of the final setup, can you spot me?

Monday, May 22, 2017

A slow but steady start

My first week back in Hengill has gone exactly as expected, full of both small achievements and some interesting challenges.

This summer I will be running our fourth and final side-stream channel experiment, in which we will investigate the effects of climate change and nutrient pollution on stream ecosystem processes, such as carbon fixation and the cycling of associated nutrients. To do this we’ll culture biofilms in side-stream channels along a temperature gradient of 5C-25C (41F-77F), while adding N and P at varying concentrations and ratios. This will allow us to understand if the concentration of a nutrient, or its relative availability to other nutrients, influences how biofilms and their coupled ecosystem processes respond to temperature.

However, before we can answer these questions the channels need to be up and running, which is proving more difficult than anticipated. Although the PIs spent the last two weeks getting the infrastructure in place and securing a constant supply of water to our site, the hot pot that warms our water is refusing to stay hot. Last year the pool was consistently around 45C; this year it struggles to hit 40C and seems unable to maintain a heat source.

If a hot pot doesn't produce hot water, is it really a hot pot?
These are the questions that keep me up at night.

I’m currently testing out a few ideas to get the heat back. Draining the hot pot completely results in an inflow of warmer water- sometimes the incoming water is 70C- that’s 158F! However, once the pool refills the pressure from the water seems to “shut off” the heat vent, and the water begins to cool. Keeping the water levels lower in the hot pot may therefore help us maintain a constant supply of hot water. I’ll be keeping an eye on the temperature in the coming days, bailing water as needed, and hoping for the best.
"The Belly of the Beast"- 
a rare glimpse into the inner-workings our volatile hot pot after I removed over 1500 L of water

Meanwhile, I’m continuing to put the final touches on the rest of the experiment. Beth and Filipa, two Master’s students from Imperial College London, lent a hand carrying out tiles to the site, which I use as the “rocks” in my experiment for the biofilm to grow on. We spent the afternoon lining the channels with the tiles, and their help sped up the process considerably.

    Set up and ready for some bioifilm

Despite the setbacks it’s been a productive first week, and I’m looking forward to a fun and successful field season- one with lots of hot water!
Look at that steam... if only this was 1 km closer to our field site...

Saturday, December 17, 2016

Visiting MSU

Recently I travelled to Montana State University to run background water chemistry and nutrient uptake samples from last summer’s side-stream channel experiment in Iceland, and of course to visit the MSU crew!

I spent the week in Bozeman working with Jane Klassen in the Environmental Analytical Lab preparing and running almost 1,000 samples for soluble reactive phosphorus and dissolved inorganic nitrogen, two important forms of nitrogen and phosphorus that are necessary for biofilm growth.

We’re interested in how increased temperature and phosphorus (simulating future climate change and eutrophication scenarios) alters biofilm utilization of available nitrogen and phosphorus, which has important implications for nutrient cycling in streams and other aquatic ecosystems. 

Biofilm grown at 25°C (77°F) with no phosphorus (left) vs. biofilm grown at 25°C with high amount of phosphorus (200ug/L P) (right). They look similar, but are they utilizing nitrogen and phosphorus differently?

Although it’s a lot of work to process that many water samples, Jane’s expertise and use of an AutoAnalyzer sped up the process considerably. 

The AutoAnalyzer and output from the analysis

The view from the lab didn't hurt either:
The most mountains I've seen since Iceland

Once the sample-running marathon was complete I got the chance to hike with Kate around one of the many mountain ranges in Bozeman- a great way to end a great trip. Thank you to Jane for her assistance with sample analysis and to Kate for hosting me for the week!

Friday, July 29, 2016

Channels Galore

The channel experiment has been running in full force for the past two months, and growth in the channels is in full swing.

Pictured: Happy Biofilm!

The channels have been getting lots of visitors recently- the Ring of Fire crew stopped by to conduct metagenomics sampling, which will give us insight into how bacterial communities change over temperature and phosphorus gradients in stream ecosystems. The Ring of Fire is a group of researchers that study geothermal regions in the Arctic to understand how stream ecosystems can act as sentinels for climate change, and we're excited to see the results of this sampling!

We've also begun our main sampling events at the channels for the summer, which include nitrogen fixation, metabolism, and nutrient uptake measurements. These metrics will help us answer the question of how stream biofilms are influenced by increased temperature and phosphorus inputs, and how these biofilm community responses drive processes such as nutrient cycling in aquatic ecosystems. Sampling has been a full group effort, and with everyone's help we've successfully completed the first round of these measurements and are gearing up for the start of the second round of sampling tomorrow. 

The crew admiring their work after a long day

The summer has flown by and the channel experiment only has a few days left, but we'll be busy up until then finishing sampling and enjoying our remaining time in Hengill!

Friday, July 22, 2016

A couple of days ago, Lila got her snail experiment off and rolling...or is that crawling? We're seeing how the phosphorus drip affects how fast snails grow in the different temperature streams. We spent the day finding the smallest snails we could.

Aren't they so cute? Wait you can't see them?

Then we got a picture of each set so we can measure their shell size using image processing software back in the lab.

Ready for their closeup

Then they got settled in their new homes in the streams. We'll let them sit and eat and grow for a few weeks before taking them out for final measurements. 

Thursday, July 7, 2016

N Fixation Nation

This week we've been working on nitrogen fixation measurements on the landscape streams. We started it out on Monday (yes, 4th of July) with the full team in the field so we could get everyone trained together.

We've been lucking out on weather lately, so I'm sure it'll downpour next week.

At the moment we're doing acetylene reduction assays (ARA), which involves collecting a primary producer sample and putting it in a chamber with an acetylene-filled balloon.

Get excited about bryophytes, people!

Liesa and Annette prepare party favors acetylene balloons
Then we pop the balloon and shake the chamber to mix the acetylene gas, take an initial gas sample, and let it incubate in the stream for a few hours.

Shaking: not as exciting as bryophytes

Ideal gas sampler:supervisors ratio is 1:5.

This leaves us with plenty of time to relax, contemplate life, nap, or all of the above.

Dr. Dan as The Thinker

Dr. Dan as The Napper

After the incubation is up, it's another shake, another gas sample collection, and then we process the primary producer biomass using highly sophisticated techniques involving kitchen strainers.

Trust me Jill, there were even more unflattering pictures of gas sampling.

Action Packers: BYOTable!

Saturday, July 2, 2016

UV or not to UV?

As the days roll past and 15N sampling dates come and go it is easy to forget that the channel experiment stops for no one! Running for almost a month now, the tiles in the experimental channels are beginning to show signs of life. The first biomass sampling of the tiles in our light experiment were collected yesterday and Lyndsie and I spent the day scrubbing tiles in the name of science!

Each channel gets one piece of UV blocking and one piece of transparent plastic, alternating which is up and down stream.

The warmer channels are starting to fill up with all sorts of biomass while the cooler temperature channels show little colonization.

Lyndsie is always hard at work and decided to check the temperatures under our UV plastic to see if they are acting like little green houses facilitating more growth. Good thinkin'!