Cephalopod distribution and ecology over the high Arctic shelves in the Laptev, East-Siberian, and Beaufort seas

The high Arctic shelves are the particularly understudied area of the Arctic. Climate change is predicted to cause increase in primary production with cascading effect on the Arctic ecosystems, and predicted increased ship traffic through the now-ice-free areas will create anthropogenic disturbance. Thus, understanding the high Arctic shelves is required. The cephalopods are ecologically important in the area, but severely understudied. We use recent samples (2014–2019) and reuse existing literature data (1901–1998) from the Siberian and Canadian high Arctic shelves to assess distribution and ecology of cephalopods. The fauna composition of these shelves is similar, and includes two benthic octopods and two nekto-benthic bobtail squids, and two more species over the adjacent slopes. Distribution limits are updated for all shelf species, and associated environmental parameters allow for better understanding of their realised niches. The reproduction of studied cephalopods occurs from July to November, and the hatching period throughout the summer. Crustaceans are their main prey, but several more taxa are found in the stomach contents. The prey sizes range from ∼7% to ˃100% of the respective cephalopod size. Climate-driven changes in predator and prey composition are predicted to be the main drivers of the future climate change impact on cephalopods over the high Arctic shelves.