Looking back at a great summer

Hello! I am Brooke Weigel, the REU student on the project this summer. I was in Iceland from the 15^th of June until the 6^th of August. This summer was a fantastic learning experience – from both living in another country, far away in the middle of the Atlantic, and through the invaluable research experience that I gained working with many inspiring grad students and mentors. It was very exciting to be part of the first summer of the project, since we had to creatively adapt our sampling equipment and procedures, among other things, as the streams required . For example, during the July landscape sampling we did “nutrient slugs” on all of the streams (and almost all in one day!). During one slug on Stream 5, Wyatt and I discovered that the salt was traveling downstream at a much slower rate than was calculated previously. In the photo you can see Jim coming to the rescue with his computer; we quickly adapted to the new travel time and modified our timing of the water samples in order to capture all of the NaCl breakthrough curve. One of the most valuable things I learned this summer is that science is always a work in progress!

In addition to helping out with the July landscape sampling, Adam and I conducted an experiment to examine the influence of temperature on the processes of benthic nutrient uptake and metabolism (see previous blog post). It was fun and challenging to come up with the procedure for sampling these chambers, since they are usually only used for metabolism. At the very end of the summer, Adam and I worked hard analyzing the data for six of the streams that we sampled. I hope to be able to continue analyzing and interpreting at the data in preparation for the NABS science conference next year.

In addition to acquiring tons of great data, we had some time to explore the beautiful country of Iceland. Here is a photo of me scuba diving in a part of the mid-Atlantic rift, which runs through Lake Þingvellir and divides the North American and Eurasian plates. The water was even colder than stream 13 – it was only 3 °C! After the project was completed, our group had a wonderful time up at Lake Myvatn. From there, I traveled around the East Fjords and down along the south coast of the island. This summer was fantastic! Thanks to everyone who made it happen.

Toom-Toom and Weigs

This summer we were lucky to have Adam Toomey and Brooke Weigel join our research team. Both are undergraduate scholars who conducted independent projects at Hengill. A Howard Hughes Fellowship supported Adam Toomey who will be a senior at Washington-Jefferson College (Washington, PA). Brooke Weigel was an REU Fellow. Brooke will be a junior this year at Saint Olaf College (Northfield, MN).

Adam and Brooke collaborated on a project examining patterns of epilithic metabolism and nutrient uptake across a temperature gradient. They incubated tiles in six streams varying in temperature from about 7 ˚C to 22 ˚C. After about month, Adam and Brooke used chambers to measure metabolism and nutrient uptake. Toom-Toom and Weigs (as they are fondly known in Hengill) used YSI probes to measure changes in dissolved oxygen (DO) during a “light” incubation (first picture) and then during a “dark” incubation (second picture). In the third picture Brooke is showing off our improvised battery pack.

Changes in DO during the “light” incubation reflect the balance of primary production and respiration. Dissolved oxygen changes during the “dark” incubation provide a measure of respiration (we assume primary production doesn’t occur in the dark). After the light and dark incubations, Adam and Brooke added stream water spiked with a small amount of nitrogen and phosphorus. They took several water samples over the next few hours to measure the uptake of nutrients by the epilithon. The forth picture shows Adam taking nutrient samples and the last picture shows epilithon from a cold stream greedily sucking up nutrients.

Toom-Toom and Weigs recently completed their projects. They hope to present their results at next summer’s North American Benthological Society meetings.

A very busy July for the team

July has been quiet with regard to blog posts, mostly because the team in Iceland has been slaving in the field. Now we're trying to catch up and post some news.

The landscape study kicked into full gear in July, helped by our two intrepid undergraduates, Brooke and Adam. Here we are unpacking the trucks for a full day of slug additions across the landscape gradient. These additions required a huge amount of planning and preparation, but went off without a hitch.

This shot gives some idea of how the team was spread out across the landscape during many days in July. I took this photo while doing slug additions in stream 9. In the foreground are Jim, Adam and Dan doing the same in stream 7. Further back, Junks is doing a slug in stream 6, while in the distance one can just see Brooke and Wyatt doing their slugs in stream 5. Beautiful! The question now is: can this be done in winter? We'll have to wait and see.

Rope sampler party

Our 'epirope-on' sampler. .  creative and nice. . .

Adam and Brooke show off the end result. These samplers have now been deployed across all the landscape study streams.