Timing of Calanus finmarchicus diapause in stochastic environments

• Published in: Ecological Modelling
• Main Authors: Bandara, Kanchana, Varpe, Øystein, Maps, Frédéric, Ji, Rubao, Eiane, Ketil, Tverberg, Vigdis
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 2021
• Subjects: Environmental heterogeneity; Bet hedging; Phenotypic plasticity; Overwintering; Oversummering; Copepods; Calanus finmarchicus
• Online Access: https://hdl.handle.net/1912/27833

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bandara, K., Varpe, O., Maps, F., Ji, R., Eiane, K., & Tverberg, V. Timing of Calanus finmarchicus diapause in stochastic environments. Ecological Modelling, 460, (2021): 109739, https://doi.org/10.1016/j.ecolmodel.2021.109739. In environments with strong seasonality, many herbivorous zooplankton remain active only during the productive season and undergo a period of inactivity and suppressed development termed ‘diapause’ during the unproductive season. The ability to time the diapause entry and exit in response to the seasonality of the environment is thus essential for their survival. However, timing of diapause may become challenging when environmental conditions vary stochastically across shorter and longer timescales, and particularly when zooplankton lack external cues to predict these variations. In this study, we used a novel individual-based model to study the emerging patterns of diapause timing of the high-latitude marine herbivorous copepod Calanus finmarchicus under shorter- (6-h) and longer-term (interannual) environmental stochasticity. The model simulated growth, development, survival and reproduction (income breeding) of a C. finmarchicus population over multiple calendar years and traced the emergence of behavioral responses and life history strategies. The emergent timing of diapause entry and exit were robust to shorter-term environmental stochasticity, which was manifested through morphological (i.e., body and energy reserve sizes) and behavioral plasticity (i.e., diel vertical migration). Longer-term stochastic variations of temperature and food environments altered the timing of diapause entry, which occurred earlier in warmer years with higher growth potential and vice versa. Irrespective of the modelled environmental variability, diapause exit occurred asynchronously throughout the year. This appeared to be a consequence of a ...