Decadal growth pattern of an indicator species Sebastes koreanus in the Yellow Sea and its response to environmental changes at differing scales

Abstract

Climate change and human activities are significantly impacting coastal ecosystems and the species that inhabit them. Understanding how individual growth of key species varies and responds to environmental changes is essential for a better understanding of population dynamics and prediction of ecological responses to environmental changes. Here, a 20-year growth history of Sebastes koreanus was reconstructed based on otolith chronology analysis. Then the relationships between environmental factors (local and basin scales) and the growth variability were analyzed using a mixed effect model. The reconstructed growth chronology showed distinct inter-annual variability that alternatively increased and decreased, and a rapid increasing trend was observed during 2011–2014. The growth pattern significantly correlated with summer Chlorophyll-a concentration, indicating bottom-up control in the coastal ecosystem of the Yellow Sea. Significant relationships were also detected between otolith growth and winter bottom temperature and summer Southern Oscillation index, the two significant factors that also represent intensity of the Yellow Sea Cold Water Mass (YSCWM), which is the most important hydrographic feature influencing the Yellow Sea. The study result contributes to better understand fish growth plasticity under environmental changes. This result also reveals the relationship between fish dynamics and the YSCWM intensity in the Yellow Sea. The growth condition of S. koreanus could be used as a biological index for the YSCWM intensity and contribute to better understand the influence of the YSCWM on fish populations.