Long-term evaluation of pelagic trophic conditions and early warning indicators in marine cage aquaculture: A case study from Güllük Bay (Southwestern Aegean Sea, Türkiye)
Regional Studies in Marine Science, vol.102, 2026 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 102
- Publication Date: 2026
- Doi Number: 10.1016/j.rsma.2026.105402
- Journal Name: Regional Studies in Marine Science
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Zoological Record
- Keywords: Decision support systems, Environmental forecasting, Mann-Kendall trend analysis, Marine cage aquaculture, Pelagic water quality, Sustainable aquaculture management
- Akdeniz University Affiliated: Yes
Abstract
Güllük Bay is a major center of Turkish marine aquaculture, contributing approximately 38% of national marine aquaculture production. This study evaluates pelagic trophic conditions and ecosystem stability using a ten-year monitoring dataset (2013–2022). Pelagic conditions were assessed by integrating the Trophic Index (TRIX), ecological carrying capacity (ECC), and TRIX-derived early warning indicators (EWIs). TRIX values remained below the eutrophication threshold (TRIX < 4), and registered production capacity corresponded to 67% of the estimated ECC. Nevertheless, EWI analysis identified increasing variance and lag-1 autocorrelation at selected stations. These patterns are consistent with critical slowing down, defined as a progressively slower recovery from perturbations as ecosystem resilience weakens, although they do not by themselves demonstrate an imminent regime shift. The results support a precautionary decision-support framework in which TRIX describes pelagic trophic status, ECC provides a production-pressure benchmark, and EWIs identify locations where monitoring and farm-level assessment should be intensified before deterioration in mean trophic conditions becomes evident.