System dynamics of the Barents Sea capelin

• Published in: ICES Journal of Marine Science
• Main Authors: Yndestad, Harald, Stene, Anne
• Format: Text
• Language: English
• Published: Oxford University Press 2002
• Subjects: Regular Articles; Arctic; Barents Sea
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/59/6/1155; https://doi.org/10.1006/jmsc.2002.1285

The capelin ( Mallotus villosus) in the Barents Sea plays a key role in the Arctic food web. The large fluctuations in the biomass of the Barents Sea capelin have been poorly understood and collapses in the biomass have occurred. A system analysis of the capelin stock has identified a state differential equation model and a frequency transfer function model of the stock properties. The results of this research show that the capelin stock dynamics is adapted to the 18.6 year and the 18.6/3=6.2 year lunar nodal tide that influences the temperature in the Barents Sea. An analysis of the capelin time series has identified a 6.2 yr cycle of recruitment, maturity and fish stock growth. An estimated frequency response of a stock-number, life-cycle model has identified a stochastic resonance of about half of the 6.2 yr cycle. The stochastic resonance shows that fluctuation of the stock number is a natural adaptation to the environment and a strategy for optimal growth and survival in the long run. In this stochastic resonance timing between the stock number fluctuation and the 6.2 yr cycle is most important.