Ocean health in focus at 2nd International Ocean Health Symposium

More than 100 international experts discuss ocean health with focus on impact of marine pathogens on ecosystem and society

On Wednesday, August 31, the second International Ocean Health Symposium came to a close at the Steigenberger Hotel in Kiel, Germany. International experts, including from the USA, Saudi Arabia, and Israel, researchers from Kiel Christian Albrechts University (CAU) and GEOMAR Helmholtz Centre for Ocean Research Kiel, as well as other institutions in Germany, exchanged views during the two-day conference on how to achieve and maintain a good state of the world's marine ecosystems. In addition to fundamental key questions about the relationship between health and disease in the ocean, the conference also focused on the classification of current extreme events such as marine heat waves and the dynamics of the spread of viruses and bacteria. It is still largely unexplored whether epidemics and diseases of marine organisms increase due to climate change or the loss of biodiversity, what role microbes play in the resilience of marine ecosystems and how stress factors affect the future availability of marine resources such as fish, mussels or algae.

"Research into different aspects of marine health, a comprehensive understanding of the consequences for the marine ecosystem and the challenge of creating an appropriate regulatory framework for the use of resources vital to humanity are among the important future topics for Kiel University," says CAU Vice President Professor Dr. Nele Matz-Lück. "The Kiel symposium has provided new impetus for research into this socially more than relevant topic," says the law of the sea expert from the Walter Schücking Institute for International Law at Kiel University.

"A variety of reasons contribute to the fact that the ocean is changing and under stress. How changes affect diverse creatures, their habitats and ultimately us humans are important questions that we want to get to the bottom of with our research," affirms Professor Dr. Katja Matthes, Director of GEOMAR. "This requires cross-cutting knowledge and action. The bringing together of many different expertises as well as the cooperation in collaboration between the university and GEOMAR makes the special strength of this symposium."

The symposium covered several questions

Will marine diseases increase due to global change? This and other topics were discussed in different sessions with international experts renowned in their field. The focus was on emerging diseases in the ocean triggered by bacteria and viruses, as well as the impact on the function of marine organisms. "Many marine pathogens are still unknown or only little researched. One of the questions that concerns us is whether infection processes in the sea differ from those on land. We want to understand which processes are responsible for the spread of pathogens, because conversely, the microbiome also contributes to the resilience of ecosystems," explains Professor Dr. Ute Hentschel Humeida, head of the Marine Symbioses research unit at GEOMAR.

How much disease does a healthy ocean need is one question when it comes to understanding how diseases not only influence ecosystems, but also regulate them. "We still know too little about why the important regulating role of parasites and pathogens suddenly turns into epidemics that cause important key species such as seagrasses, corals or sea urchins to die en masse, with destructive effects for the entire marine ecosystem," says Professor Dr. Thorsten Reusch, head of the Marine Ecology Research Unit at GEOMAR, who was in charge of organizing the international Ocean Health Symposium. "In science, we also talk about the dark matter of biodiversity, as we assume that there are numerous species with a parasitic lifestyle. However, such species are important ecological players in the ocean, and we encounter them when studying many native ecosystems such as mussel beds and seagrass meadows," Reusch added.

Interdisciplinary approach to ocean health research

Researching the topic of Ocean Health requires an interdisciplinary approach. The Kiel organizers' invitation was accepted by scientists from the fields of physical, chemical and biological oceanography, ocean system modeling and prediction, data science, infectious disease biology, as well as climate and biodiversity research, economics and philosophy.

"In Kiel, we are ideally positioned for holistic research into the topic of ocean health, because we don't even know about many novel diseases in the ocean yet," explains microbiologist Professor Dr. Ruth Schmitz-Streit, director of the Institute of General Microbiology at CAU and coordinator for the research field Biological Marine Systems in the Kiel Marine Science (KMS) research focus. "We are interested in the dynamic courses in the spread of viruses and the molecular interactions with animals, plants or fungi. Our research aims to identify those factors that can also trigger diseases in humans - currently using the example of vibrios in the sea. And here we need experts who can build a bridge from research into individual pathogens to their significance for the marine ecosystem and ultimately for humans."

How can we best manage the societal and economic impacts of marine pathogens? And how can marine ecosystem management succeed in the face of numerous unknown factors? "We are studying the interactions between society and marine ecosystems, and how, for example, disease outbreaks in marine aquaculture can affect food security. Our goal is to derive options for action for effective management across time, space and borders," emphasizes Professor Dr. Marie-Catherine Riekhof, Director of the Center for Ocean and Society (CeOS) and Professor of Political Economy of Resource Management at the Institute of Agricultural Economics at Kiel University.

The 2nd International Ocean Health Symposium was jointly organized by the Kiel Marine Science (KMS) at CAU and the GEOMAR Helmholtz Centre for Ocean Research Kiel and supported by the Center for Ocean and Society (CeOS) / KMS, the Collaborative Research Center (SFB) 1182 "Emergence and Functioning of Metaorganisms" and the Helmholtz Research Field Earth and Environment (Topic 6, Marine Life), and strengthens the interdisciplinary and cross-faculty research activities on "Ocean Health" at Kiel. Furthermore, the symposium has been accepted as an activity within the UN Decade of Ocean Research and contributes to Goal 2 "A healthy and resilient ocean".