Working Group: Algal Adaptation

Large brown macroalgae are foundation species for highly diverse and productive ecosystems along rocky coasts of temperate and Arctic latitudes. As the distribution of these marine forests and meadows is mainly constrained by temperature, ocean warming and increasingly frequent and intense marine heatwaves are reducing the size and diversity of populations, ultimately leading to local extinctions especially at species’ warm range edges.

Recently, documentations of climate change effects on natural ecosystems and isolated organismic responses to single or few interactive environmental variables have increased our understanding of the resilience of brown algae ecosystems. However, to learn how these organisms may adapt to comprehensive environmental disruptions, holistic approaches employing the entire life cycle and different levels of biological organization are necessary.

Our aim is to fundamentally understand the natural variation of brown algal stress tolerance from molecules to ecosystems, to (1) estimate the adaptive capacity of the ecosystem as a whole and to (2) allow informed decisions on protective and restorative measures.

To this end, we are conducting experiments in the wild, in near-natural communities in GEOMAR’s state-of-the-art mesocosm facilities (https://www.geomar.de/en/discover/kiel-benthocosms) and under controlled laboratory conditions. Combining eco-physiological phenotyping techniques, population genomics and transcriptomics, we investigate how brown algae respond to climate change within their natural communities and in isolation. We describe the variability of key traits and examine artificial selection and breeding as tools to potentially reinforce natural ecosystem resilience.