Looking out on the waters of Lochaber lake the words “serenity”, “tranquility”, and “stillness” come to mind. The waters often appear still, being protected from wind by the steep sloping hills which surround Lochaber. Some vegetation thrives along the coastline, and the banks of the lake descend into a 70 m deep tectonic rift in the centre of the lake. Aside from two seasonal turnover events, the water in Lochaber does not mix vertically, and instead is contained to a fixed depth for much of the year. It seems as though nothing much happens in the waters of Lochaber. However, collecting carbon dioxide exchange data and meteorological data from Lochaber on an hourly basis for more than a year had me put this notion to rest. An active, dynamic zonated production line is busy at work right under our noses in the littoral zone.
As a third year Environmental Science student, with some experience in the study of CO2 efflux from soils and lakes, I was excited to learn what the waters of Lochaber had in store. I knew this project would be no light task; designing, building, installing, and maintaining a CO2 monitoring station using a novel technique for which there were no “How to Guides”. Once every component of the station was working in the field, I thanked my lucky stars, and thought the hard part was over. I was fortunate in many ways; the station was 30 minutes from my home and could nearly be driven up to which allowed frequent check-ups and tinkering as needed. When we decided I should measure a few variables periodically, to collect more information and check my automated measurements, I was more than happy to have another reason to visit my station at Lochaber. Even if 7 of these visits involved collecting water and gas samples at 1:00 AM and asking generous friends for help. Often, I would go for a swim while my samples incubated on the lake, and I don’t imagine I’ll be fortunate to have such a leisurely research project in the future.
This siesta from head-scratching was short-lived, however. The variables known to effectively explain CO2 efflux in the pelagic zone were not effectively explaining the CO2 efflux I observed in the littoral zone, and my head was filled with questions. Shouldn’t the littoral zone primarily be a sink for carbon dioxide, with all the vegetation around? Shouldn’t wind velocity, or at least the ratio between water and air temperature, aptly explain patterns in CO2 exchange, as it does in the pelagic zone? After hundreds of statistical analyses across different timescales, from hours to months, using a litany of Lochaber littoral, limnetic, and lacustrine variables (and alliteration), we finally came to a conclusion. The littoral zone of Lochaber is the zone of a mad processing frenzy, much like an orchestra composed of soloists, and many variables were concurrently interacting to regulate the unique spatiotemporal patterns we were seeing.
Looking out upon the smooth waters of Lochaber, the waters seem to be still and dormant. Aside from the occasional fish, fly, or snapping turtle (which have a habit of hiding in the shadow of floating gas measurement chambers and swimming between the legs of unsuspecting technicians, leading to sudden bouts of colourful language), it seems that the littoral zone is static and silent. But, if we could hear the sound of microbes munching, macrophytes respiring, and gases exchanging across the boundary between air and water, our ears would be flooded with an off-beat orchestra characterized by a cacophony of episodic percussions with no common beat.
Furthermore, closest from shore, this orchestra would be ten times louder than just 10 m further from shore, though on a variable basis across the seasons. The geologic record tells us that tectonically-formed lakes like Lochaber are long-surviving relics on the landscape because of their deep rift and stable morphology relative to other lake types. So, we’ll expect this orchestra to continue its cacophony, though hopefully we can better come to perceive its symphony.
Through the course of this project, I was able to practice my technical independence, work on my summer tan and swimming skills (though you wouldn’t guess as much from seeing my swim), and explore uncharted territory in the field of biogeochemistry. It was as rewarding as it was challenging, for so many reasons. As an undergrad student, this two year project will have lifelong-lasting implications on my credentials, experience, and tenacious attitude towards tackling challenging research projects. Many thanks to everyone who helped me build, install, and maintain this beastie, as well as those who helped me untangle the results – especially Christina Minions, Chris MacIntyre, Kirsten Gallant, Jacob Johnson, and Renée McDonald. Also thank you to Dave Risk for his bottomless store of patience and Bob Inglis for the use of his beautiful property.
By: Lynsay Spafford