Claessens at his office in Pearson Hall.
Photo by Lisa Tossey
What role do streams play in removing nutrients from our waters? Assistant Professor of Geography Luc Claessens, who joined the College of Earth, Ocean, and Environment (CEOE) in September, is working to answer that question.
Claessens explained that urban and agricultural areas typically harbor abundant nutrients — things like excess nitrogen from fertilizers used on fields and lawns or from burning fossil fuels. When washed downstream, those nutrients end up in coastal waters and create problems.
“You can get an increase in algal blooms,” he said, “which has a big effect on food webs and recreation.”
Claessens researches the interactions between hydrology and ecosystem processes, and is particularly interested in the effect of changes in land-use and climate, and the development of adaptive management practices to mitigate the impacts of those changes. He uses a variety of approaches in his research, including field experiments and monitoring, modeling, and geospatial analysis.
“I use spatial thinking,” he said. “If we know that certain practices make sense from a scientific perspective, we can determine where in a watershed we should focus those practices and put our money to say, engineer the landscape, or restore wetlands or restore riparian areas to really do a good job to reduce nutrient export.”
Claessens didn’t start out as a geographer though. A native of the Netherlands, he earned an undergraduate degree in tropical agriculture and worked in Latin America before heading to Colorado State University. There he got a bachelor’s degree in agricultural engineering and a master’s degree in civil engineering.
After holding research positions at NASA’s Goddard Space Flight Center and Woods Hole Marine Biological Laboratory, he earned his doctorate in geography from the joint program at the University of California at Santa Barbara and San Diego State University.
“I was interested in interdisciplinary work that brings together the different sciences but also the human component,” he said. “I was also interested in something that was very spatial, and so I kind of discovered geography.”
As part of his doctoral studies, he looked at the role of small urban streams in controlling nitrogen export. He did that nearby in Maryland, in collaboration with the Baltimore Ecosystem Study, a long-term ecological research project. During and after his doctoral work, he also held a teaching position at the University of Connecticut. Before coming to UD, he worked as a research scientist at Virginia Tech on projects aimed at reducing nutrient loads from urban and agricultural watersheds.
At UD, Claessens is continuing his collaboration with the Baltimore Ecosystem Study as well as initiating research on nearby watersheds — including the Christina River and the Indian River. Apart from studying the impacts of land-use changes, he also has plans to continue previous research on the effects of climate change on water availability and quality.
When it comes to CEOE, he said the opportunity to leverage the multidisciplinary knowledge of colleagues who are experts in geography, geology, and marine sciences is a real strength.
“The thing that I really benefit from is the scientific discussion with, say, a biogeochemist, but also there’s a lot of overlap in terms of the techniques that we use, whether it’s GIS or some of the analytical techniques,” he said. “And there’s also a system connection — whatever we do upland has an effect downstream on the coast.”
The avid runner moved to the area with his wife, an estuarine ecologist, and two young children.