A marine heatwave (ocean heatwave) is an extended period of time in which the water temperature in a particular ocean region is abnormally high. In recent years, heatwaves of this kind have caused considerable changes to the ecosystems in the open seas and at the coast. Their list of negative effects is long: Marine heatwaves can lead to increased mortality among birds, fish and marine mammals, they can trigger harmful algal blooms, and greatly reduce the supply of nutrients in the ocean. Heatwaves also lead to coral bleaching, trigger movements of fish communities to colder waters, and may contribute to the sharp decline of the polar icecaps.
Researchers led by Bern-based marine scientist Charlotte Laufkötter have been investigating the question of how anthropogenic climate change has been affecting major marine heatwaves in recent decades. In a study recently published in the well-known scientific journal Science, Charlotte Laufkötter, Jakob Zscheischler and Thomas Frölicher concluded that the probability of such events has increased massively as a result of global warming.