Genetics and species distribution
On most marine keystone species there is available ecological information. However, information on their changing geographic distributions through space and in time is seldom available. Temperature is a key feature to determine the geographic distribution for most organisms. Therefore, due to climate change, many species have already begun to shift their ranges. Using genetic data, it is possible to track both past and present biogegraphic changes, identify past and present-day hotspots of high genetic diversity.
Genetics and fish distribution
MarBEF researchers have analysed how environmental factors (e.g. temperature, salinity) influenced the spatial structure of fish populations. They also examined how the spatial distribution of these populations changes over time (e.g., whether the populations expand, relocate or shrink).
These analyses showed that the steepest gradient in genetic variation overlapped spatially with the steepest gradient in salinity. This gradient was located in the western Baltic - Belt Sea area. The analyses also showed that the populations in the Baltic were genetically distinguishable from those in the North Sea.
This sort of knowledge can be used to help improve the way fisheries are managed and inspected. It can help to identify and trace the geographical origin of fish sold on markets and might even help to find out whether the fish have been caught from protected areas. These technologies have in fact already been used to convict fishermen for illegal fishing. 
Genetic markers and biodiversity
The GBIRM (Genetic Biodiversity) project has helped to resolve the phylogeographic structure (the geographical distribution of different taxa) of a set of species. This enables scientists to make predictions about how global and local disturbances can influence large-scale population structures and distributions in the coming decades.
The EPIC (Exon Primed Intron Crossing) project has helped to identify genetic markers (DNA sequences) which are present in the nuclear genome of all animals. The discovered markers provide extremely informative data to study biodiversity. This is because they are sufficiently different to study different populations of the same species and yet are still similar enough to be used between different phyla. A potential source for such markers are numerous introns (a region of DNA) which are located on the same position in many species, even belonging to different kingdoms.
- Heip, C., Hummel, H., van Avesaath, P., Appeltans, W., Arvanitidis, C., Aspden, R., Austen, M., Boero, F., Bouma, TJ., Boxshall, G., Buchholz, F., Crowe, T., Delaney, A., Deprez, T., Emblow, C., Feral, JP., Gasol, JM., Gooday, A., Harder, J., Ianora, A., Kraberg, A., Mackenzie, B., Ojaveer, H., Paterson, D., Rumohr, H., Schiedek, D., Sokolowski, A., Somerfield, P., Sousa Pinto, I., Vincx, M., Węsławski, JM., Nash, R. (2009). Marine Biodiversity and Ecosystem Functioning. Printbase, Dublin, Ireland ISSN 2009-2539