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Related Experiment Video

Updated: Nov 23, 2025

Establishment of Microbial Eukaryotic Enrichment Cultures from a Chemically Stratified Antarctic Lake and Assessment of Carbon Fixation Potential

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Resource-driven colonization by cod in a high Arctic food web.

Edda Johannesen¹, Nigel G Yoccoz^2,3, Torkild Tveraa³

¹Institute of Marine Research Nordnes Norway.

Ecology and Evolution

|January 4, 2021

Summary

Atlantic cod (Gadus morhua) expanded into the Arctic Barents Sea due to warming and high food availability. However, their long-term residency is uncertain as cod abundance impacted prey availability.

Keywords:

Barents Sea abiotic biotic hierarchical design marine food webs range expansion spatial distribution stomach data

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Area of Science:

Marine Biology
Climate Change Ecology
Fisheries Science

Background:

Arctic marine ecosystems are experiencing rapid warming and associated species redistributions.
The Barents Sea, a key Arctic ecosystem, has seen above-average temperatures and a significant increase in Atlantic cod (Gadus morhua) populations.
Divergent bottom temperature trends exist across Barents Sea subregions.

Purpose of the Study:

To investigate the influence of food availability and temperature on the northward expansion of Atlantic cod in the Barents Sea.
To determine if food availability, indicated by stomach fullness, played a role in cod expansion across areas with different temperature trends.

Main Methods:

Utilized a comprehensive dataset on cod stomach fullness, stratified by Barents Sea subregions.
Analyzed cod expansion in relation to subregional temperature trends (warming, cooling, no trend).
Assessed the role of food availability (stomach fullness) in cod expansion patterns.

Main Results:

Greatest cod occupancy increases were observed in three northern subregions with varied temperature trends.
Initial high food availability in these northern areas, previously lacking large predators, supported cod expansion.
Cod stomach fullness declined rapidly after a few years, indicating a top-down effect on the prey base.

Conclusions:

Cod expansion into the Barents Sea is influenced by both temperature and prey availability.
The arrival of cod can lead to a rapid depletion of local prey resources.
The long-term persistence of cod in the northern Barents Sea is not guaranteed due to these top-down effects.