Genetic population structure of Baltic Sea eelgrass - urgent information for conservation of a foundation species under climate change

Biodiversity loss and climate change are two of the grand challenges of our time.Maintaining biodiversity, within and between species and ecosystems, will become increasingly important to avoid the worst impacts of climate change.

Despite the fact that genetic diversity is the level at which selections acts, hence influences individual and species survival, it is rarely used in environmental conservation.The seagrass Zostera marina(eelgrass) is one of the most important habitat-forming species around the Swedish coast. It has declined considerably and is at risk of further decline due to climate change, not least in the Baltic Sea.

Management to mitigate further losses must take into consideration genetic diversity of eelgrass.

This is clearly demonstrated by our earlier work showing a surprising genetic complexity of eelgrass on the Swedish west coast.

Focusing on the Baltic Sea, we will use I) genomics to provide a baseline of current genetic diversity and connectivity for future genetic monitoring of Baltic eelgrass; II) oceanographic modelling of current and future climate scenarios, useful for prioritizing meadows for protection and restoration; and III) demographic modelling to assess meadows’ ability to recover and adapt in the future.

The final aim is to develop a spatial management guide for Baltic eelgrass under climate change, which will help the responsible authorities to meet key requirements of national, EU and UN directives and Sustainable Development Goals.