Dramatic Ecological Changes After an Unusual Winter Cold Snap

Although average temperatures are increasing globally, abrupt cold stress in winter can occur regionally. For example, the winter thermal gradient between the Arctic and middle latitudes is weakening because Arctic temperatures are rising faster. This phenomenon can lead to pronounced cold air outbreaks in Eurasia and North America in winter. In eastern Canada, an unusual cold snap occurred in February 2023. In intertidal habitats from southeastern Nova Scotia, entire mussel stands disappeared and some seaweeds experienced massive bleaching shortly afterwards. Winter extremes related to climate change can therefore be as important for species survival as summer heat waves.

These photographs illustrate the article “Mass disappearance of intertidal mussels after an unusual winter cold snap in eastern Canada”, published by Nicole M. Cameron, and Ricardo A. Scrosati in Ecology. https://doi.org/10.1002/ECY.4179.