Polar Biology: Ontogenetic movements of cod in Arctic fjords and the Barents Sea as revealed by otolith microchemistry

A new paper by Hector Andrade1, Peter van der Sleen2, Bryan A. Black3, Jane A. Godiksen4, William L. Locke V5, Michael L. Carroll1, William G. Ambrose Jr.6 and Audrey Geffen7,8 has been published in the journal Polar Biology: “Ontogenetic movements of cod in Arctic fjords and the Barents Sea as revealed by otolith microchemistry”.

1Akvaplan-niva AS, Norway, 2Wildlife Ecology and Conservation Group, Wageningen University, The Netherlands, 3Laboratory of Tree-Ring Research, University of Arizona, USA, 4Institute of Marine Research, Norway, 5Department of Biology, Bates College, USA, 6School of the Coastal Environment, Coastal Carolina University, USA, 7Department of Life Sciences, Imperial College London, UK, 8Department of Biological Sciences, University of Bergen, Norway.

Abstract: 

The distribution of Atlantic cod (Gadus morhua) in northern Norwegian waters is expanding eastward and northward in the Barents Sea and along western Svalbard. In the Arctic fjords of Svalbard, cod has become abundant, but little is known about the biology, origin, or residence patterns of these populations. To address this issue, we used laser ablation inductively coupled plasma mass spectrometry to quantify the trace elemental composition of cod otoliths at age-0, age-3 and the year of spawning at five distinct locations in northern Norway and western Svalbard. Chemical composition data was used to identify natal sources of cod, their broad-scale migration patterns, and to determine if cod are currently resident in Arctic fjords. Our results suggest that cod collected at Kongsfjord, Isfjord, outside Svalbard, Lofoten, and Porsangerfjord were recruited mainly from the Barents Sea, conforming to the Northeast Arctic cod ecotype. The degree of chemical overlap between Porsangerfjord and Isfjord cod, however, varied with fish age, suggesting individual movements consistent with the Norwegian coastal cod ecotype. Finally, the chemical composition of mature fish at Isfjord, and to a lesser extent Kongsfjord, suggests that cod from the Barents Sea might have recently established residency in these two Arctic fjords.

Reference: 

Andrade, H.; van der Sleen, P.; Black, B.A.; Godiksen, J.A.; Locke V, W.L.; Carroll, M.L.; Ambrose Jr., W.G.; Geffen, A. (2020): Ontogenetic movements of cod in Arctic fjords and the Barents Sea as revealed by otolith microchemistry. Polar Biology (2020). https://doi.org/10.1007/s00300-020-02642-1. [intranet]