Can a key boreal Calanus copepod species now complete its life-cycle in the Arctic? Evidence and implications for Arctic food-webs

• Published in: Ambio 2022-02, Vol.51 (2), p.333-344
• Main Authors: Tarling, Geraint A., Freer, Jennifer J., Banas, Neil S., Belcher, Anna, Blackwell, Mayleen, Castellani, Claudia, Cook, Kathryn B., Cottier, Finlo R., Daase, Malin, Johnson, Magnus L., Last, Kim S., Lindeque, Penelope K., Mayor, Daniel J., Mitchell, Elaine, Parry, Helen E., Speirs, Douglas C., Stowasser, Gabriele, Wootton, Marianne
• Format: Article
• Language: English
• Subjects: Animals; Arctic environments; Arctic Regions; Atmospheric Sciences; Calanus finmarchicus; Changing Arctic Ocean; Community structure; Copepoda; Developmental stages; Earth and Environmental Science; Ecology; Ecosystem; Environment; Environmental conditions; Environmental Engineering/Biotechnology; Environmental Management; Food; Food Chain; Food chains; Food webs; Habitats; High temperature; Ice environments; Lipids; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Physical Geography; Phytoplankton; Plankton; Seasons; Species; Traditional foods; VDP; Webs; Wildlife; Wildlife habitats; Zoologiske og botaniske fag: 480; Zoology and botany: 480; Zooplankton
• ISSN: 0044-7447; 1654-7209; 1654-7209
• DOI: 10.1007/s13280-021-01667-y

The changing Arctic environment is affecting zooplankton that support its abundant wildlife. We examined how these changes are influencing a key zooplankton species, Calanus finmarchicus , principally found in the North Atlantic but expatriated to the Arctic. Close to the ice-edge in the Fram Strait, we identified areas that, since the 1980s, are increasingly favourable to C. finmarchicus . Field-sampling revealed part of the population there to be capable of amassing enough reserves to overwinter. Early developmental stages were also present in early summer, suggesting successful local recruitment. This extension to suitable C. finmarchicus habitat is most likely facilitated by the long-term retreat of the ice-edge, allowing phytoplankton to bloom earlier and for longer and through higher temperatures increasing copepod developmental rates. The increased capacity for this species to complete its life-cycle and prosper in the Fram Strait can change community structure, with large consequences to regional food-webs.