"High-resolution temporal monitoring of marine biodiversity in Gotland"

How variable is the coastal ecosystem in the sea around Gotland over a year? Which species are present, how common are they and how does their composition change over the year? These are questions that Sara Kurland, a postdoctoral researcher at Uppsala University, will investigate. With more knowledge about the relationship between species, it will also be possible to better adapt fishing and harvesting to local conditions.

Knowledge of the coastal ecosystem around Gotland during the winter months is poor. But with new technology, there are good conditions for finding the missing pieces of the puzzle. Since summer 2023, Sara Kurland has been working as a postdoctoral researcher at Uppsala University. She uses the eDNA technology to find DNA traces of organisms in the water.

A woman stands in front of open water holding an instrument.
Sara Kurland takes water samples on the coast of Gotland. Photo: Viktor Jacobsson, Uppsala University

Water samples show DNA traces and environmental variables

Once a month, from November 2023 onwards, Sara Kurland and her colleagues will visit six sites to take samples. They are mainly looking for eDNA, but also measure water salinity, temperature and other environmental variables.

There are several advantages to eDNA, explains Sara Kurland, it is a non-invasive and non-damaging technique and can be used to identify different types of organisms including algae, zooplankton and phytoplankton that are present. For fish in particular, DNA libraries are available at the species level, while for zooplankton, for example, it is possible to find out which group they belong to.

By taking enough samples often enough, it is possible to find out which organisms are present and how they interact with environmental variables such as plankton levels. And while eDNA does not reveal the age or health of individuals, it can provide important information for understanding the web of marine organisms and their interactions throughout the year.

We take the samples to a lab, filter them and send them for analysis, says Sara Kurland. The answer comes in the form of Excel sheets that I work on, so the project has one foot in the field and one in the office. When the collection and analysis are complete, we will know more about the conditions for sustainable resource use in terms of methods and timing of fishing and collection.

A map of Gotland with locations marked with numbers
The places where Sara Kurland takes water samples

A method that can be used anywhere.

The concrete results of Sara Kurland's project will mainly be applicable to Gotland and the Baltic Sea, but in a later stage the method and protocols will be applicable anywhere. And over a number of years, the method could also show the effects of climate change.

In my department there are researchers studying angling and in my research group there is a doctoral student doing a similar project in Zanzibar, so there are several opportunities for other fruitful collaborations.

Background in biology and the blue

For Sara Kurland, working on issues related to food is new and educational, but she has a solid background in biology and the blue. She has a master's degree in evolutionary biology from Uppsala University, with a year at McGill University in Canada, and wrote her master's thesis on threespine stickleback. Her doctoral thesis at Stockholm University was about monitoring genetic variation in natural populations, with trout in lakes in Jämtland as a study object. And since the summer of 2023, Visby is her workplace.

It's great to live and work by the Baltic Sea, says Sara Kurland. It's close to the sea, and on Gotland the contact routes to authorities and other important contacts are also short. There are good conditions for a successful project.

The project is relevant to Blue Food research area 5. Sustainability analysis.

Sara Kurland's project is expected to be completed in spring 2025.


Unlike doctoral students, postdoctoral researchers have no supervisors, but Sara Kurland works closely with Lina Mtwana Nordlund and Gunilla Rosenqvist, who are also active in Blue Food.

Sara Kurland's profile page on the Uppsala University website