Food web dynamics affect Northeast Arctic cod recruitment.

Area of Science:

• Ecology
• Climate Science
• Fisheries Science

Background:

• Ecosystem management necessitates understanding species interactions and climate impacts.
• Time-series data often vary in length, complicating ecological analyses.
• Previous studies on Northeast Arctic cod recruitment were limited by specific ecological and climatic conditions.

Purpose of the Study:

• To develop a general approach for analyzing dynamic structures in ecological time-series data of varying lengths.
• To model the impact of prey species (capelin and herring) on Northeast Arctic cod recruitment.
• To investigate cod recruitment variation using long-term data, extending beyond recent specific conditions.

Main Methods:

• Developed a novel modeling approach to handle differing time-series lengths.
• Constructed a model incorporating the influence of capelin and herring on cod recruitment starting in 1973.
• Analyzed historical data on cod, herring, and temperature spanning back to 1921.

Main Results:

• Identified significant food-web effects influencing cod recruitment.
• Demonstrated that these food-web effects explain a substantial portion of recruitment variation.
• Extended the explanatory power of ecological factors back to approximately 1950.

Conclusions:

• Food-web dynamics play a crucial role in the recruitment variability of the Northeast Arctic cod stock.
• The developed methodology allows for more robust analysis of ecological interactions using heterogeneous time-series data.
• Long-term ecological factors, particularly prey availability, are critical for understanding cod stock dynamics over extended periods.