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Because of climate change, coral species are now disappearing on a massive scale: Within just a few decades, the global coral population has dropped by half. Many corals are poorly prepared to respond to further increases in ocean temperatures due to their evolved thermal tolerance to pre-climate change temperature regimes. This is tantamount to an economic and ecological catastrophe.

Konstanz biologist Professor Christian Voolstra has resolutely pursued the goal of investigating the living conditions of coral and finding a way for them to survive climate change. For his outstanding research achievements in this field, Voolstra was now honoured with the Mid-Career Scientist Award of the International Coral Reef Society (ICRS). The ICRS has 827 members from 67 countries and promotes the production and dissemination of scientific knowledge to secure coral reefs for future generations. The award is presented once per year and this year was the first time it went to a German scientist.

Voolstra's research particularly focuses on the interplay between corals and microorganisms. In addition to photosynthetic algae, coral also have a symbiotic relationship with bacteria, which support coral well-being in various ways. Outcomes of his research contribute to the development of coral probiotics – a method by which corals are inoculated with bacteria that help them to cope better with changing conditions. The aim is to enhance coral resilience to the extreme and rapid changes occurring in their natural habitat and, eventually, to prevent reefs from going extinct.

Voostra's outstanding scientific contributions further include coordinating  the "Tara Pacific Expedition" with a group of international scientists: On board the schooner Tara, he travelled the Pacific Ocean for more than two years from 2016 to 2018 in order to research the living and survival conditions of coral. A total of 40,000 samples were collected. Up to that point, there had not been such an all-encompassing survey of the living conditions for coral.

Another main feature of Voolstra's research is the mobile testing system, "Coral Bleaching Automated Stress System" (CBASS), that he and his colleagues have been developing and that makes it possible to rapidly identify particularly heat-tolerant coral in the ocean. For coral it is very difficult to adjust to rising ocean temperatures. Warming by just one degree leads to mass mortality of the sensitive organisms in some regions. With the help of CBASS, researchers can find coral that exhibit superior thermotolerance  that can then, for instance, be used as a source for restoration of dying coral reefs. The project is funded with a total of 4 million US dollars from the Paul G. Allen Family Foundation.

In his research, Voolstra also investigates the reasons underlying coral bleaching. His research team found out that corals “bleach before they pale”. In layman terms, contrary to common belief, coral starvation sets in even before they lose their nutrient-providing symbiotic algae, and not as a consequence of it. Thus, the cause for coral bleaching, and eventually death, is a disruption in the symbiotic metabolic cycling between corals and their algae that starts long before the paling, i.e. the loss of algae, begins.

Key facts:

• Mid-Career Scientist Award of the International Coral Reef Society (ICRS) for Professor Christian Voolstra from the University of Konstanz
• The award honours researchers who have made outstanding research contributions in the field of coral research for at least ten years
• This year was the first time it went to a German scientist