The work, led by the ICM-CSIC shows that marine microbial networks exhibit recurrent patterns of assembly and disassembly influenced by environmental factors like temperature.
Marine microbes play a crucial role in maintaining the health of our oceans and the planet as a whole, since they are responsible for processes such as recycling nutrients or breaking down pollutants. To survive, these tiny organisms form complex networks of interactions that contribute to the overall functioning of marine ecosystems. However, our understanding of microbial interactions is still limited, making it difficult to fully grasp their impact on the ocean's health and climate change.
New research led by the Institut de Ciències del Mar (ICM-CSIC) in collaboration with researchers from the University of Oslo (Norway) and the University of Nantes (France) has unveiled that marine microbial interactions follow an annual cycle. Concretely, the study points out that the interaction network disassembles and reassembles when transitioning seasonally between colder and warmer waters, suggesting a strong connection between seasonal changes and microbial interaction networks.
“We found that marine microbial associations exhibit recurrent patterns influenced by environmental factors like temperature. As the climate changes, these factors are altered, potentially impacting the composition, structure, and stability of microbial networks. This, in turn, could disrupt essential processes such as nutrient cycling and energy transfer within the marine environment”, states the former ICM-CSIC researcher Ina Maria Deutschmann, leading author of the study.
To carry out the study, published recently in the journal Microbiome, researchers analysed a 10-year marine time series from the Blanes Bay Microbial Observatory (BBMO) in the Mediterranean Sea, which is one of the longest-running microbial observatories in the world. Then, they developed a temporal network for inferring the interactions for each microbial sample, allowing scientists to examine microbial association dynamics over time, shedding light on how these interactions change in response to environmental factors, including ocean warming.
According to the authors, this novel approach could serve for testing season-specific microbial interaction hypotheses, and could be applied to microbiome studies in other ecosystems, ultimately contributing to a deeper understanding of the intricate relationships that govern our natural world.
Lastly, the work reveals a higher repeatability of interactions during colder months, indicating that certain interactions may be more consistent in specific conditions. However, only 0.1% of the total number of associations were confirmed by existing literature, highlighting the knowledge gap in understanding marine microbial ecological interactions. This emphasizes the need for further research to unlock the mysteries of these vital networks and their influence on marine ecosystems.
“In light of ocean warming, future research lines should focus on understanding the effects on marine microbial networks by studying diverse ecosystems, integrating functional data, increasing temporal resolution, validating associations through experiments, and developing predictive models to inform conservation strategies”, exposes in this regard Ramiro Logares, co-author of the work.
All in all, the findings, financially supported by the Spanish projects INTERACTOMICS and MINIME, as well as the European project SINGEK, underline the importance of accounting for the temporal dynamics of microbial interactions in marine ecosystems to understand better the functioning of the ocean microbiome and its impact on climate change and marine life, and pave the way for future research in this vital study area.