The changing coast - Pathogenic bacteria and climate change

The ecosystem of the German Bight is not only one of the worldwide “hot spots” strongly affected by climate change but - as an important economic region - also subject to numerous direct anthropogenic influences like tourism, fishery operations, shipping traffic, pollution & eutrophication from various sources, and recently, the set-up of wind farms at sea. With our focus on microbes these two aspects, climate change and anthropogenic pressure are under investigation in this topic.

Vibrio are consistent members of the marine microbial rare biosphere and exhibit typical patterns of opportunistic boom and bust when optimal (typically mesophilic) conditions prevail. Water temperature is known to be the strongest factor determining the distribution of a number of Vibrio spp., most of which are human pathogens found in both shellfish and the water column. They can range from unidentifiable in the winter to highly abundant during summer blooms with outbreaks typically seen in climates warmer than those experienced in, e.g., the North Sea. This may partly explain why Vibrio monitoring efforts in the German Bight are altogether lacking. As such, we are unable to assess the current potential threat of Vibrio pathogens to human health and economy in Europe. This is particularly alarming, as the extent to which climate change will influence the distribution of pathogenic Vibrio species is not known. It is likely that warmer waters, high stream flow rates, and aberrant climate patterns will encourage the spread of Vibrio, including pathogenic strains, into northern temperate waters, as has been predicted in similar coastal systems. As phages play a key role in bacterial genomic diversity, they may contribute to changes in Vibrio pathogens from environmental populations. Hence the role of Vibriophages in the development of these pathogenic populations is of particular interest.

PACES: Topic 2 WP2