Joanna Wolstenholme, a third year NatSci undergraduate, has just wrapped up seven weeks helping our field campaign in Canada. She authored this entry, describing her experience.
Sudbury, on first inspection, is a rather spread-out mining town, inhabited by many trucks (most of them blue). However the more you explore, the more remarkable the town becomes. It is one of the few areas of the world where remediation has really worked, and the next generation will inherit a greener and cleaner city than the one that their parents inherited. This remarkable change, from a barren ‘moonscape’ caused by years of acid rain (Sudbury was once the world’s largest point source of sulphur dioxide emissions, thanks to large-scale nickel and copper mining), to an area with burgeoning forest cover and recovering lakes, is a great success story that the area can be immensely proud of.
With this backstory, Sudbury, with its 330+ lakes, makes an ideal experimental location for a group dealing in ecosystems and global change. Our study lake, Daisy Lake, is perfectly set up for studying the effects of terrestrial influences on aquatic ecosystems. Along its length, the shores and wetlands have recovered to various degrees. One catchment has even been limed – covered with calcium carbonate to neutralise the acidic soils, and so plant growth is relatively lush. Other areas, closer to the smelter at the north end of the lake, are far more barren; bare, stained rock predominates, with a few stunted trees.
In Daisy, we were studying eight stream deltas, each with very different personalities. At each site Erik and I measured algae, sediment, and water. This all sounds very easy in theory, but in practice (as with any fieldwork, as I came to learn) things were far harder and more complicated… and often involved some rather novel solutions. If nothing else, this placement has certainly given me plenty of opportunities to stretch my problem solving skills!
My first job was to build algae-collectors, which were plastic tubes with cut up swim floats attached from which 6 microscope-slides dangled from fluorescent string. These floated on the surface, but we also sank clay pot holders as another surface for algae to grow on. We left these in the lake (on a beautiful sunny day) at each of the deltas and then returned to collect them 3 weeks later. On a more high-tech note, we also made use of two chlorophyll fluorometers to characterise the algal species found in the water column and benthic layer. After several dry runs measuring the amount of algae on Erik’s office floor, we took them out to the lake, and used them at each of the deltas. The unseasonal amount of rain that Sudbury was experiencing, however, complicated things, and meant that in some sites Erik had to swim with the fluorometers, as we couldn’t reach the sediment from the boat.
As well as working on Daisy with Erik, I also helped Andrew collect additional data for his survey of terrestrial resource use by aquatic organisms. This meant going out to six other lakes around Sudbury, and six down in the Muskokas, to collect water samples, use fluorometers, and deploy and collect the microscope slide contraptions. Key to the project was collecting clean leaf and algal samples, to go off for stable isotope analysis, to allow Andrew to calculate the influence of the terrestrial systems on the lake ecosystems.
In order to grow clean algal samples without the influence of terrestrial DOM, we collected water from each of the lakes, then filtered it into jars and re-inoculated each jar with a small amount of unfiltered lake water, from which we hoped the algae would regrow. This seemed simple in theory, but involved hours of standing by a vacuum pump watching water drip through a filter. One night, we actually filtered water outside a hotel, so as not to set the fire alarms off! Safe to say we got many odd looks. However, the field trip down to the Muskokas was one of the best perks of the summer. We went down in September, almost at the peak of the colours changing, and had two lovely dry but crisp days. Driving down dirt tracks through beautiful forest, to find beautiful lakes to paddle out into was great fun, and a real adventure! It definitely offset the tedium of filtering.
At the end of my seven weeks here I am very sad to be leaving. It was a great experience, with plenty of messing about on boats, exploring new places, and making new friends. I have learnt a lot about the complications of fieldwork, how to solve problems on the fly with limited supplies, and just what really goes on behind those simple sounding ‘Materials and Methods’.