Exploring the adaptive behaviour and environmental acclimation of artificially-bred Chinese sturgeon (Acipenser sinensis) in semi-open marine environment: insights for endangered species conservation

Abstract

The Chinese sturgeon (Acipenser sinensis) is a critically endangered, large migratory fish that serves as a vital indicator of ecological status of marine and river environments. Conservation efforts for Chinese sturgeon primarily focus on freshwater rearing, potentially leading to smaller adult sizes and higher disease incidence due to limited exposure to marine environments. Thus, it is imperative to study the behavioural characteristics and marine life history of artificially reared populations in seawater environments. In this study, acoustic telemetry technology was employed to investigate the behaviour of the Chinese sturgeon. We deployed an acoustic array at a nearshore-fenced marine farm on Bailong Island and conducted a one-year (December 2020–December 2021) tracking of ten acoustic-tagged fish, comprising five adults and five juveniles. We generated distribution heat maps and analysed displacement during typhoons and tidal events to differentiate activity levels. Annual distribution revealed areas of distinct increased density, with adults displaying a denser distribution compared to the more scattered pattern observed in juveniles. Rhythmic behaviour in response to tidal cycles was observed. During typhoon periods, individuals exhibited reduced activity levels but increased concentration, with no significant diurnal behavioral variations. These age-specific and environmentally responsive habitat preferences provide valuable supplementary insights into the species' life history and potential conservation strategies.

Graphical Abstract