October 6, 2017

Freya Olsson

Freya Olsson

PhD: Working with natural processes to restore lake habitatsCEH Lancaster

Email Freya Olsson at CEH

Email Freya Olsson at Lancaster University


I graduated from Durham University in 2016 with a joint-honours degree in Biology-Geography within the Natural Sciences programme. As part of my final year studies, I completed my dissertation assessing the impact of historic metal mining on stream chemistry and riparian biodiversity in the Yorkshire Dales. This project involved the collection and analysis of water, sediment, and vegetation samples, as well as ecological data across two upland catchments. Throughout my undergraduate studies I became increasingly interested in the interactions between landscape, processes, and ecosystem functioning, and my dissertation sparked a particular interest in freshwater ecosystems.

Research Project:

Now based at the UK Centre for Ecology & Hydrology and Lancaster University, I am using field sampling and computer models to examine the effects of changes in lake residence time on ecosystem function, with a particular focus on how residence time manipulation could be used to restore eutrophic lakes. A lake in the English Lake District recently underwent restoration to reduce the residence time of the system, through hydrologic manipulation, setting up a natural experiment to investigate the physical, chemical, and biological parameters effected by residence time changes.

My first paper uses the General Ocean Turbulence Model, a 1-D physical lake model to look at how changes to lake residence time affect water temperatures and stratification dynamics, key aspects of lake functioning. I hope to extend this understanding to see how residence time changes may interact with other meteorological changes under a warming climate.  A second paper utilises existing and newly collected field data to understand the effect of the restoration at Elterwater specifically – has the intervention been effective in improving water quality? A final chapter will use high-frequency oxygen and temperature profiles to look at short-term fluctuations in deep water oxygen and the relationship with short term changes in water residence time. Concentrations of oxygen in bottom water are important in determining the internal loading of nutrients from lake sediments, which can cause water quality problems.

As part of my PhD I have been fortunate to be working with Natural England on a CASE (Collaborative Award in Science and Engineering) partnership, synthesising the research on lake hydrology as a basis to inform lake management.


See the below research poster for more information about Freya’s exciting research. This poster was created by Freya during an Infographics training course delivered by Infohackit and organised by Envision.

An image of Freya's research poster aimed at a stakeholder audience