Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic

The jellyfish Periphylla periphylla, which can have strong ecological impacts on its environment, is ubiquitous in the Norwegian Sea and its range was predicted to extend northwards. The occurrence of P. periphylla in the northern Barents Sea increased since 2014 and, for the first time, several individuals were collected within a high Arctic fjord (> 78°N) in western Spitsbergen in January 2017. The low solar irradiance prevailing during the...