Tipping the scales: Are marine opportunists pathogens an increasing threat in a changing climate?

Principal Investigator: Mark Fast
Co-Investigators: Maya Groner, Colleen Burge, & Morgan Eisenlord

Diseases in marine organisms are increasing in their ecological, economic, and social impacts. In many cases, this is associated with effects of climate change, including increasing sea temperatures. Understanding how these changes affect diseases is an important first step towards easing their negative impacts. This is especially true in a large, but poorly understood group of marine pathogen protists (neither plant nor animal nor fungus). Protist pathogens are opportunistic, and have been associated with disease in many species directly associated with fisheries (hard clams and abalone) or habitat (seafans and seagrasses). The impacts of climate change on this group of pathogens are poorly understood.

Using seagrass wasting disease (WD) as a model system, this project explores the role of changing temperature as a driver of the disease in seagrass, with the aim of identifying defenses in the host and virulence factors in the pathogen that may change with temperature.

We paired an outdoor experiment with a genomic study to understand how temperature affects infection loads, eelgrass health, and the regulation of defensive and virulence factors. We found disease severity and pathogen loads were higher at higher temperatures.

Although the genetic transcription is not finalized, this will be the first simultaneous examination of transcriptional responses to infection in both the host and the pathogen for this disease, and promises to yield exciting insights about diseases caused by these common, but poorly understood pathogens.