Environmental change and diseases of marine organisms


In oceans, marine organisms live in a ‘microbial soup’ – in persistent contact with literally billions of microorganisms. Whilst many of these are beneficial, some can become nasty under certain conditions and cause disease. Climate change is predicted to increase the spread and virulence of microbial pathogens. At the same time, the rate of ocean warming is causing physiological stress in many marine organisms, increasing their susceptibility to diseases. Combined with other human impacts (e.g. higher nutrients, pollution, etc.), we may be facing a major rise in the effect of disease on natural communities.


An increase in diseases could have big impacts in marine ecosystems, particularly when they affect ‘ecosystem engineers’ – organisms that create or modify the environment in a way that facilitates other organisms. Seaweeds are the ‘trees of the oceans’, dominant habitat-forming organisms that provide food and shelter to many other marine organisms.


Globally, large habitat-forming seaweeds are declining from temperate reefs and our research investigates whether environmentally-mediated diseases may be one of the causes of these declines. The loss of kelp forests and other seaweeds due to disease would radically change marine environments, so understanding potential reasons for their declines is extremely important.