DTU Aqua’s research into Population Genetics aims to gain knowledge on how to preserve and manage biodiversity in a sustainable manner. We focus on this in relation to both recreational and commercial exploitation (fisheries), biodiversity conservation and aquaculture.
This knowledge is achieved through studies of evolutionary processes, which are responsible for generating and maintaining genetic diversity within and among populations of marine and freshwater fishes.
DTU Aqua develops and employs state-of-the-art molecular genomic tools for genetic traceability and for restoring and managing local fish populations.
Research into Population Genetics has five main themes:
We describe the distribution of fish populations (stocks) and their diversity from regional to fine-scale areas. Are there, for example, one or several cod populations in the Baltic Sea and of eel in the Sargasso Sea? And to which extent is there a genetic exchange between local populations? We determine the distribution and the size of the individual population, now and historically.
Genetic traceability and monitoring
We develop methods for tracing the species and origin of individual fish and fish products. We also use genetic data to:
evaluate effects of stocking and habitat disturbance
determine the migratory behaviours of individual fish populations
determine which fish reproduce
find out how we can restore endangered populations in a sustainable manner that take population histories and local adaptations into consideration.
We examine whether local populations are genetically adapted to their environment. This knowledge is used to understand evolutionary processes in general, and is also applied as a fish management tool, e.g. for determining whether releases may contribute to rebuild endangered or locally extinct populations.
Genetic impact of climate change
We examine whether climate change affects the distribution and the genetic composition of populations. We analyse genes that are related to temperature adaptation in order to study whether local populations are likely to 1) adapt genetically, 2) alter their distribution (e.g. relocate to northerly areas), or become extinct due to global warning.
Genetic impacts of fisheries
We analyse DNA from historical samples to study whether fishing has affected the distribution and genetic composition of fish populations. We use the results to illustrate the impact of different types of fishing on genetic resources and to infer how fisheries can be directed to best conserve the genetic variation.
Why do we do research into Population Genetics?
Population Genetics focus on describing the genetic differences between populations of fish, between the individuals within the same population and between fish in aquaculture. For example, a brown trout from a river in the eastern Jutland does not have the same genetic fingerprint (DNA profile) as a brown trout from a river in the western Jutland, just as the North Sea cod does not have the same genetic fingerprint as the Baltic Sea cod.
The genetic variation of contemporary fish populations is the result of evolutionary processes, reflecting both geographical separations of populations over thousands of years and genetic adaptation to local conditions.
The genetic differences can be analysed and described using modern DNA technologies and they provide important information on the factors influencing the distribution and dynamics of populations. They also provide us with a technical tool for tracing individual fish and fish products back to the areas or aquacultures from which they came.
What is the research used for?
Population genetic analyses are used to determine which fish from which populations are caught to avoid overexploitation of small and vulnerable populations. The analyses may also be used to control illegal fishing by testing whether landed fish and fish products originate from species and stocks which can legally be caught.
Genetic monitoring also plays an important role in planning the long-term management of fish resources. The work is carried out by comparing DNA from contemporary fish samples with DNA analyses of samples from historical time series.
We compare DNA from fish scales and otoliths sampled more than 100 years ago, providing insight into how wild populations have responded to stocking, fishing and environmental change. Inference from our research can thus be used to guide management to preserve the genetic variation, resulting in healthy and productive fish populations that can be exploited sustainably.
View projects within the research area "Population Genetics" in the project database DTU Orbit.
Senior Research Scientist Dorte Bekkevold, tel. +45 35 88 31 30,
Professor Einar Eg Nielsen, tel. +45 35 88 31 15,