The microbiome in the life cycle of jellyfish blooms

The increase of nuisance blooms of specific organisms in the worlds ocean has been linked to anthropogenic impacts, climate change and the associated deterioration of ecosystems. The blooms often abruptly collapse described by a boom-and-bust, causing a major perturbation to the ecosystem and its services. The factors and mechanisms behind this type of dynamics remain enigmatic. While the role oof the microbiome for the hosts traits is increasingly recognized, the the role in the boom-and-bust population dynamics of its host remains unknown. Decaying jellyfish blooms were recently recognized as significant but largely overlooked source of labile organic matter in the ocean. The ambition of this project is to elucidate the role of the microbiome in the life and decay of its gelatinous bloom-forming host. We will focus on the composition and functional traits of the jellyfish microbiome at the transition from a healthy to senescent stage of the hosts bloom to elucidate the role of the microbiome in the bust and collapse of jellyfish blooms. We hypothesize that in the development and decay of jellyfish blooms the microbiota plays a decisive role. We will focus on all jellyfish microbiome components fungi, prokaryotes and viruses and will cover different degrees of microbiome specialization from host- species , -body compartments, -health status, and stage of bloom development. We will cover our in-situ survey with manipulation experiments under controlled laboratory conditions. All biotic and abiotic data collected will be funneled into the first open access jellyfish microbiome database, which will serve as the first step towards a better understanding of jellyfish-microbiome interactions. By providing insight into the factors controlling the boom- and-bust population dynamics this project contributes to predict and mitigate the detrimental effects on ecosystems.