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.

Tuesday, June 21, 2016

Ecological Engineering

Science involves making measurements to estimate process that are sneaky and difficult to measure. To prepare for this, we need an arsenal of equipment specifically designed for the task at hand.

Bond. James Bond.
Annette (right) and Delor (left), ready to glue anything into submission

Liesa (left) and Annette expertly inventing

"Your mission, should you chose to accept it, is to construct a sampling chamber that can be used for incubations in the light, darkened to measure the same processes with no light, along with creating a device to circulate the water in the chamber without interfering with measurements. This message will self-destruct."
The St. Kate’s team has chosen to accept this challenge, in addition to helping with stream sampling as a part of the larger Hengill 2016 crew. Liesa and Annette have been expertly preparing equipment for upcoming analyses, flexing their engineering muscles and showing off their scientific prowess.


An Ecological Stir Plate, in all it's glory
The chambers in question hold our samples, along with a stir bar. This stir bar is propelled by magnets attached to a computer fan – an ecological stir plate. As the magnetic fan spins, so does the stir bar thus stirring the water to mimic conditions found in the stream within the chamber. This stir plate has been carefully water-proofed so it can be completely submerged in the stream – a handy modification for processes that need to be measured in stream ecosystems, and certainly no easy task. Good thing we have handy women to take on the task! It has been great getting to see Liesa and Annette jump into these tasks with fervor, using their backgrounds growing up tinkering and their natural curiosity. Will this adhesive work? What are the limitations? Is it safe for aquatic environments? Not only have they been asking the right questions, they have been tenaciously working to find the answers. As Nobel prize winning chemist Michael Levitt said, “If you know where you’re going, you’re not gonna find anything really interesting”. Innovation and curiosity have brought us to solutions that are both interesting and functional!



We have darkened chambers with an expert mix of duct tape, adhesive, and garbage bags. Ecologists are nothing if not resourceful! Keep an eye out for more updates as we see if the equipment can hold up to the capricious Icelandic conditions as well as these Minnesota women can.

All of our hard work is paying off!

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