Evaluation of the Residency of Black Rockfish (Sebastes schlegelii) in Artificial Reef Areas Based on Stable Carbon Isotopes

The ecological 'attraction' and 'production' functions of reef areas have been the subject of ongoing debate requiring further clarification. The present study focused on the black rockfish (Sebastes schlegelii), an economically dominant species in reef areas of Dabuquan Bay. Comparisons of stable carbon (C) isotopes between the muscle and liver tissues of black rockfish were conducted to identify residency and potential sources of non-resident individuals in the coastal Yellow Sea, China. Subsequently, isoscape values, derived from C isotopes of zooplankton gathered from inshore and offshore areas surrounding the reef, were compared to determine potential sources of the non-resident black rockfish individuals. According to the results, (1) the isotopic values between the muscle and liver tissues of black rockfish remained consistently aligned across both reef and control areas but showcased significant seasonal variations, and (2) the residency ratios of individuals within the reef area exceeded 84% across all seasons, highlighting the prolonged stays of this species. The findings are consistent with previous studies on rockfish residency and could facilitate the formulation of strategies for local stock enhancement and management.