Project BaltVib - Pathogenic Vibrio bacteria in the current and future Baltic Sea waters: mitigating the problem

Vibrio microbes which are part of the natural bacterioplankton in temperate marine waters have flourished in the Baltic Sea in recent years, probably stimulated by elevated surface water temperatures. Several Vibrio species are human pathogens. It is hence of great concern that Vibrio-related wound infections and fatalities have increased dramatically along the Baltic coasts. Future climate change is predicted to escalate this problem, posing a significant threat to human health and the Baltic tourism. However, this projections do not yet take into account the influence of characteristic habitats such as eelgrass meadows, macroalgae or blue mussels beds on Vibrio diversity and abundance. Recent data indicate that in some of these ‘ecosystem engineers’ habitats the abundance of pathogenic Vibrio spp. is reduced. This could open up the option for nature-based solution (NbS) strategies to control pathogenic Vibrio in nearshore habitats where humans interact with the sea. However, climate change will also affect the structure and functioning of coastal habitats, with as yet unknown consequences for the Vibrio populations in the Baltic Sea. BaltVib aims to delineate the current and future Vibrio status, determine biotic and abiotic key factors regulating Vibrio prevalence, and identify NbSs to mitigate the problem. This will be accomplished through interdisciplinary integration of marine, microbiological, molecular and socioecological expertise carried by partners from seven Baltic nations.

The expected scientific impact of the project involves:

• Knowledge about the regulation effect of selected habitat types and of abiotic environmental factors on Vibrio distribution and pathogenicity across the Baltic Sea salinity gradient.
• Identification of the Vibrio mitigation extent of selected habitat types (ecosystem engineers).
• Transfer into a knowledge-based management plan to conserve or expand these habitats and their associated beneficial ecosystem functions.

National authorities of the partner countries with responsibility for public health, bathing water quality, MSFD and WFD will be actively included in the decision-making process. Politicians, stakeholders and the general public will be actively engaged to foster understanding of the need to protect and restore the biodiversity of seagrass meadow habitats as potential biofilters to conserve or reach a good ecological status of coastal waters and to protect human health.