Dr Michelle Jackson, Research Associate and Ecologist at Imperial College London, is working on ‘Ring of Fire’, a four-year, NERC-funded research project that investigates the impact of rising temperatures on freshwater ecosystems. Here, she discusses the challenges of fieldwork in the Arctic and the results that make it all worthwhile.
Our planet is warming at an unprecedented rate. Year on year, temperature records around the world have been repeatedly broken. Last winter saw the lowest ever recorded levels of ice covering both poles; 2016 was the hottest year on record and Britain just experienced its hottest June day since 1976.
Following five consecutive days of 30 degrees celsius heat in London, I am preparing for a trip to colder climes in the Arctic as part of our Ring of Fire research project. The project, led by Imperial College London’s Professor Guy Woodward, investigates how increasing temperatures, such as those caused by global warming, could affect freshwater ecosystems, such as rivers and lakes.
Freshwaters are particularly vulnerable to climate change – the World Wildlife Fund’s Living Planet Index estimates that populations of vertebrate species have fallen by over 80% since 1970. In addition, rivers and lakes are valuable sources of hydropower, food and water – both for drinking and agriculture. Therefore, the impact of climate change on these systems will have direct implications for human health.
Our team of scientists are visiting five geothermal sites in the Arctic Circle, which give the project its name, ‘Ring of Fire‘, to find out how warming could affect everything from bacteria to the flux of greenhouse gases in and out of the stream. At each location, different geothermal heating of the bedrock and groundwater means that some streams are much warmer than the surrounding air, while others are still very cold. They can vary in temperature between 3 to 45 degrees Celsius, providing the ideal natural laboratory to measure how warming will affect many aspects of the stream, including food webs, microbial diversity and whole ecosystem processes, such as respiration.
‘Ring of Fire’ is already well underway. Last year, we visited Iceland, Alaska and Greenland, and we currently have team members back in Iceland collecting additional data: PhD student Bruno Gallo is investigating how warming affects fish populations using a molecular approach, while researcher Dr Emma Ransome is looking at how bacteria communities respond to rising temperatures.
Of course, although these sites provide fantastic data, undertaking fieldwork in the Arctic comes with a host of challenges. Some are expected, such as the cold and the seasickness, others much less so. In Greenland, for instance, an inquisitive Arctic fox cub made daily raids to our sites, running off with the flags we were using to mark our sampling locations. Another time, due to unpredictable tides, we had to spend the night on a beach keeping warm by a driftwood fire.
This July, I will travel to Svalbard, a small island to the north of Norway, with colleagues from Queen Mary University of London and the University of Essex. To say it’s remote is something of an understatement. The journey alone involves flying to Longyearbyen via Oslo, and transferring to a boat called MS Farm to take us on a 30-hour trip further north. Our final destination will be some hot springs near Bockfjorden, a fjord in Nordvest-Spitsbergen National Park – home to polar bears, arctic foxes, walrus and reindeer. In preparation, we have been trained in survival and first aid, as well as learning how to use bolt-action rifles: in Svalbard, it is against the law to leave town without a gun, due to the risk of encountering polar bears.
Collecting this data may involve enduring freezing temperatures and intimidating wildlife, but the challenges are well worth it. By covering five separate locations and combining this with experiments at Imperial, we can gather comprehensive data sets that will provide invaluable insight into the impact of global warming across the planet. This means we can ask the question ‘is there a global ecological response to global warming?’.
Research in the past has focused on the response of individual large-bodied species, such as the shift in range of polar bears. In contrast, our work focuses on the whole food-web including everything from the microbial community, to invertebrates and fish. This research will help us understand how rising temperatures will affect the composition of these microbial communities and the processes they drive, such as denitrification (the process where nitrates in the stream are turned into nitrogen in the atmosphere). As a result, we will be able to predict how global warming will affect freshwater ecosystems in the future – and what this could mean for the environment on a global scale.