Chemical recovery of a fish farm in Jinju Bay of South Korea after cessation of long-term fish farming

Abstract

The development of aquaculture technology has led to significant increases in aquaculture production, which has deteriorated the coastal environment. This study is the first to conduct sedimentary environment recovery monitoring of an aquaculture environment using chemical indicators in a fallow fish farm in South Korea. The total organic carbon concentration in the surface sediments (≤2 cm) decreased to the control level within 1 year; the acid volatile sulfide concentration was not recovered for 3 years and 10 months. Nutrient and sulfide concentrations were high in deep sediments (≤15 cm) because of continuous fish farming for over 20 years and accumulation of organic matter beneath the cages. Complete chemical recovery of this study area may take a longer time than previously anticipated. Overall, this study provides significant insights for implementing coastal management plans and estimating adequate fallowing periods during long-term fish farming.