Responses of fish population structure to barrage re-opening in an estuarine ecosystem
Frontiers in Marine Science, vol.12, 2025 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 12
- Publication Date: 2025
- Doi Number: 10.3389/fmars.2025.1542823
- Journal Name: Frontiers in Marine Science
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Pollution Abstracts, Directory of Open Access Journals
- Keywords: brackish water species, estuarine ecosystem restoration, Nakdong River Estuary, non-indigenous species, re-openings of estuary barrages
- Middle East Technical University Affiliated: Yes
Abstract
Background: Re-openings of estuary barrages for ecosystem restoration are rare globally. The Nakdong River Estuary (NRE), South Korea, provides a unique opportunity to assess the effects of temporary barrage re-opening on fish population structure. Methods: We conducted monthly fish population surveys both upstream and downstream of the estuary barrage from 2021 to 2023, categorizing results into closing period (CP) and opening period (OP). Results: During the OP, we observed shifts in fish distribution, including decreased proportions of non-indigenous species and altered habitat distributions. Additionally, we observed an increase in brackish water species populations and their upstream movement. Monthly frequency analysis revealed that brackish and non-indigenous species exhibited high frequencies mainly during OP (July to October), while freshwater (demersal) species showed low frequencies during the same period. Discussion: Our study highlights the significant impact of temporary estuarine ecosystem restoration on fish distribution and emphasizes the need for careful consideration of both frequency and duration of estuary barrage re-openings.