Stock Status of Noncommercial Fish Species in Aras Dam Reservoir: Mismanagement Endangers Sustainable Fisheries

Abstract

Aras Dam reservoir, a key inland fishery in northwest Iran, faces increasing socioecological threats that jeopardize sustainable resource use. To provide updated information on stock conditions under limited data availability, this study applied the catch maximum sustainable yield (CMSY++) model using biometric measurements and catch records from 2013 to 2022. Four noncommercial species commonly harvested in the reservoir-silver bream (Blicca bjoerkna), common bream (Abramis brama), common roach (Rutilus rutilus), and freshwater bream (Carassius auratus)-were assessed. Stock status was evaluated through biomass relative to reference points (B/BMSY) and fishing mortality (F/FMSY). Results revealed unsustainable conditions for common bream, common roach, and freshwater bream, while silver bream remained in a healthy state. These findings suggest that maintaining current fishing levels may intensify pressure and risk stock depletion for several species. The CMSY++ model demonstrated efficiency in providing rapid assessments in data-limited situations, offering insights for inland fishery management. To ensure sustainable fisheries in the Aras Dam reservoir, managers should implement stricter measures to control illegal fishing, reduce excessive effort, and promote recovery of depleted stocks.