Multiple configurations and fluctuating trophic control in the Barents Sea food-web

• Published in: PLOS ONE
• Main Authors: Sivel, Elliot, Planque, Benjamin, Lindstrøm, Ulf, Yoccoz, Nigel G.
• Format: Text
• Language: English
• Published: Public Library of Science 2021
• Subjects: Research Article; Barents Sea; Subarctic
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270156/; http://www.ncbi.nlm.nih.gov/pubmed/34242282; https://doi.org/10.1371/journal.pone.0254015

The Barents Sea is a subarctic shelf sea which has experienced major changes during the past decades. From ecological time-series, three different food-web configurations, reflecting successive shifts of dominance of pelagic fish, demersal fish, and zooplankton, as well as varying trophic control have been identified in the last decades. This covers a relatively short time-period as available ecological time-series are often relatively short. As we lack information for prior time-periods, we use a chance and necessity model to investigate if there are other possible configurations of the Barents Sea food-web than those observed in the ecological time-series, and if this food-web is characterized by a persistent trophic control. We perform food-web simulations using the Non-Deterministic Network Dynamic model (NDND) for the Barents Sea, identify food-web configurations and compare those to historical reconstructions of food-web dynamics. Biomass configurations fall into four major types and three trophic pathways. Reconstructed data match one of the major biomass configurations but is characterized by a different trophic pathway than most of the simulated configurations. The simulated biomass displays fluctuations between bottom-up and top-down trophic control over time rather than persistent trophic control. Our results show that the configurations we have reconstructed are strongly overlapping with our simulated configurations, though they represent only a subset of the possible configurations of the Barents Sea food-web.