Marine primary producers in a future climate: an eco-evolutionary approach combining experimental ecology and metagenomics

Primary production, the build-up of organic carbon, is considered the most valuable process in the global ocean. The major part of the marine food web depends on the inherent energy of this organic matter, produced by autotrophic unicellular organisms, or so called phytoplankton. However, the Earth and its ecosystems are rapidly moving into a new human-mediated geological epoch named the Anthropocene. In the face of the ongoing anthropogenic Global Change, the key planktonic realm is subjected to new environmental conditions, inevitably forcing species to adaptive evolution or local extinction. Given a likely scenario, can we predict the performance and eco-evolutionary responses of diverse autotrophic organisms responsible of fundamental processes in the marine ecosystem? A potentially advisable approach to the question is to capitalize on the implicit ecological knowledge-potential of different types of
existing data, or data we are technically capable of producing today. The aim of the proposed research is to combine metagenome, experimental and historic monitoring data to predict the effects of global climate change on primary producers in the ocean. The project combines 1) beyond state-of-the-art metagenome population genomics, 2) transcriptome profiling of pre-Anthropocene revived resting cells and 3) species distribution modelling of a key phytoplankton species across natural environmental gradients in a “Darwinian
laboratory”, the Baltic Sea-North Sea transition. The Baltic Sea model system acts as a “time machine”, providing us with invaluable early-warning signs that facilitate the understanding of climate induced effects also in other coastal areas. The project will significantly advance methodological norms within the field of molecular ecology focused on unicellular eukaryotes. Altogether, this will bolster our ability to understand anthropogenically induced impacts on marine ecosystems, and diversify the environmental management toolbox used in coastal areas around the world. These outcomes serve the targets included in United Nations Sustainable Development Goals, especially the Climate Action and Life Below Water targets.

Phytoplankton play a key role in the oceans, with massive ecological impacts on the surrounding biotic and abiotic factors in an ecosystem. They provide earth with about 50% of all available oxygen, serve as an irreplaceable food source for higher trophic levels and function as a significant sink for atmospheric carbon. Acute ongoing environmental changes are taking place in the ocean, forcing
phytoplankton species to adapt or vanish. This project focuses on potential genetic mechanisms responsible for such adaptations. The proposed research, which is conducted at Åbo Akademi University, will serve as a novel model for the wide community of phytoplankton researchers focused on genomic and functional diversity of species adapting to changing environmental conditions. It uses big data sets in combination with progressive methodology in order to project the response of key phytoplankton species to environmental change, such as climate change and eutrophication.