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). How similar are the biofilm communities? 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!

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!

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. 

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!

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'!

The name's Tope. Iso Tope.

Today is Day 19 of the 15N sampling, and the dripper stopped adding the nitrogen isotope on the evening of Day 5, as planned. The worry of contamination is less of a flashing lightbulb now, but we are keeping up the same routines to avoid contaminating our upstream samples with the enriched downstream samples. Jon left on the evening of Day 5, but before we started doing any isotope sampling, he gave a thorough explanation of what to do and what not to do to keep the samples separate.

We were all young and naive before, but...

...it's been an enriching experience for us all! Ba dum bum tsss

Jill and Liesa have been meticulously (and I do not use that word lightly!) picking out primary producers from the isotope sampling sites along each stream. The primary producers will be the first to assimilate the 15N isotope into the food web.

"Wow. Look at that guys."
"Look at what, Jill?"
"The moss."

Even Jon had fun while he was here!

Ok that's enough fun for one day, watch where you're spraying that thing!

After leaving Stream 18 on Day 5, we encountered a large group of backpackers. They're here in Iceland from Greater Sudbury, Ontario for an Ecohealth class. They offered us some of their fermented shark, but we didn't accept. Any guess as to why?

"Would you like some fermented shark? It's gross."
"No."

After each isotope sampling day in the field, we retreat to the indoors to pick things like this:

Oh, you can't see them? Neither can I.

From samples that look like this:

A new audiobook for each bag!

But it would be deceptive if I didn't also point out that there are large things like worms and caddisflies in the streams.

A lone caddisfly and its mobile home, made of all natural, Icelandic rocks. Only 900 kronur!

It was a tough beginning, but the sampling days are spread out now that the dripper is no longer running. Much later, after all this summer business is over, the samples we bring home will be analyzed to measure how much 15N is contained in the different trophic levels so we can get an idea of who's eating who in the food web. Speaking of food...

"Day off" in field speak translates to "open the hatch."

Dammin' It Up

Hengill has been kind to us in the last few weeks, and we've experienced some uncharacteristically pleasant weather in the field.

Not a bad walk to work if you ask me

However, the lack of rain meant the reservoir for the channel experiment was running low- not a good situation when the success of your experiment relies on a constant supply of water. So Delor and I set out to improve the reservoir dam using the two most useful supplies we could think of- sandbags and rocks.

There are plenty of rocks available at the site, but what do you do when you realize it's pretty difficult to carry a bunch of 50 pound sandbags almost a mile across a field to the dam? ...

You make your own of course!

It turns out making sandbags is super easy, and much less expensive than buying them at the Húsasmiðjan (Icelandic hardware store).

Step One: Fill plastic bags with sand from the site

Step Two: Cut up some burlap and tie it around the bag

Step Three: Voilà! Sandbags!

Versatile, customizable... perfect for all your damming needs.

Using our newfound handiwork Delor and I were able to patch up the dam and get the water levels back up in the supply barrels.

It's basically on par with the Hoover Dam now.

Now we can rest easy and enjoy all these sunny, clear days… we’ll see how much longer they last!

Drippin' and tearin'

While Lyndsie was away at a conference in Canada, Delor and Nate took charge of caring for the channel experiment. This included a lot of tinkering and the fixing of several leaky couplers, because when does anything go our way during field season?

The answer is close to never. But we're flexible!

We are going to see if spray painting the black sections of the cold pipe white will help minimize solar heating of the water and keep the temperature down.

Spray paint also works as sunscreen! Don't try this at home.

The nutrient drippers require frequent maintenance, and Delor has acquired a certain fondness for the tinkering involved.

Her excitement is masked by tubes and exasperation.

To keep the pesky (but really cute) sheep from trampling the tubes, we set up an ominous warning sign.

"Stepping on the pipes is baa-aa-ad for you!"

At the end of the day, an additional field season in Hengill means an additional season of wear on the bank where we enter and exit the river. It's looking pretty worn out, so we have been examining possible side routes that will not result in falling back into the river. In the meantime, we've been keeping our boots on when we leave so we can hop out and lighten the load!

We're really just trying to give that bank the boot!

Big day tomorrow

The 15N additions are all going smoothly. We are getting ready for the Day 4 water sampling that will be done tomorrow. A total of 264 samples of various dissolved fractions will be taken across the four streams. The Geopump will be running hot!

Twice the fun: 15N additions started

What's more fun than a dripper adding stuff to your stream? Two drippers adding DIFFERENT stuff to your stream! Last night Dan Nelson and Jon Benstead started the 15N additions in the four streams along the temperature gradient. So for the next five days each stream will have two drippers going - one adding phosphorus and one adding 15N-enriched nitrogen at tracer levels. Lots of work ahead of us as we follow where all the isotope goes and find out how temperature and phosphorus addition interact to affect nitrogen uptake and routing through the food web. Below is a shot of Stream 11 (our coldest stream), with the phosphorus dripper on the right and metering pump delivering the isotope on the left. 

What day is it again?

Our team size increased +1 with the arrival of the hot off the press, straight outta grad school, PhD holdin' Dr. Dan!

What's up, Doc?

Iceland has been unusually generous with her fair weather this summer, but hey, I'm not complaining! We took advantage of another sunny day and brought everyone out for some training.

Not pictured: swarms of midges and black flies in our eyeballs.

We're preparing everyone for the high volume of work that will follow the start of the N15 isotope drips. In the meantime, Jon took drip rates and refilled the phosphorous barrels!

Sometimes you just gotta put your foot down! To block the stream.

Jill watches Jon intently.

Jill continues to watch Jon intently.

After spending a day collecting FBOM(fine benthic organic matter), epilithon, and macroinvertebrate samples, we spent the next day in the lab doing some live picking (much more fun than dead picking).

Just a lazy Sunday morning...and afternoon...

Not only did we have to pick the bugs out, but we had to sort them so we can get separate N15 readings for the different trophic levels in the stream. The live bugs don't know their fates are sealed, so they still put up a fight. One of my many worms somehow squirmed underneath its own dish!

"Is this the way back to Stream 9?"

The midges are tough to identify with the naked eye, so we made good use of the microscopes for those guys.

All that lab time in Bozeman came in handy!

It took all day, but we picked our way through all 28 samples! Nice job, team! We only have to do that for the rest of the summer!

Maybe I should just retire and take this cat's job.