Freshwater lakes throughout the world are in poor condition, mainly due to decades of heavy nutrient pollution. The main cause of poor water quality is excess phosphorus (P), which is an essential nutrient for all living organisms and causes excessive growth of phytoplankton, leading to poor water quality and loss of biodiversity in our lakes.
On land, there is a very different challenge. Here P is a valuable fertilizer for global food production and at the same time a limited resource being mined from P rich rocks located in very few countries. Hence, there has been an increasing focus on reusing P from e.g. sewage sludge and other waste products, and in general, promoting a more P sustainable attitude in society. This way of circular thinking will now permeate to lake management, where we will co-think lake restoration and P recycling by removing P from the lakes and bring it back on the fields where it is needed. However, there might be challenges in addition to other added values associated with a circular P approach for lakes. Hence, e.g. too high concentrations of heavy metals in sediment might hinder the application of lake sediments to the fields, whereas a reduced emission of greenhouse gases after a sediment removal might provide added value to lake restoration.
**We are looking for an enthusiastic and ambitious candidate with an MSc degree in biology. The candidate will be in charge of a two-year monitoring campaign in the Danish Lake Ormstrup. The overall aim is to correlate sonar mapping to general sediment characteristics, obtained by detailed high-resolution sediment core sampling to “ground truth” the sonar data. The selected candidate will be responsible for monitoring seasonal changes in nutrients, metals, and gases in the lake sediment, by various methods (e.g. modified sequential extraction protocols, 31P NMR analysis, diffusive gradient in thin films (DGT´s), and sediment GHG analyses). In addition, the establishment of macrophytes depends on different sediment conditions such as density, organic content, lability, and oxygen availability, and the selected candidate will use the sonar data to track the distribution and development of macrophytes and correlate the sonar data with sediment conditions optimal for macrophyte growth.
The PhD scholarship covers the area of aquatic ecology, biogeochemistry, and chemistry and will be aligned with ongoing research at the Freshwater Ecology group at the Department of Biology, University of Southern Denmark. The candidate will be part of a group working with P and carbon turnover and greenhouse gas emissions from wetlands, streams, and lakes, which will ensure a fruitful research environment.