Comparative Evaluation of Destructive (EEI-c) and Non-Destructive (BEARI) Macroalgal Indices for Ecological Status Assessment of Aegean Coastal Waters

This study assessed the ecological status of the Aegean Sea coasts of Türkiye using the destructive Ecological Evaluation Index continuous (EEI-c) and non-destructive Benthic Ecological Assessment Rapid Index (BEARI) macroalgal indices within the framework of coastal ecological monitoring. A total of 25 coastal stations were investigated and macroalgal taxa were classified into sensitive Ecological Status Group I (ESG I) and Benthic Ecological Group I (BEG I) and tolerant–opportunistic Ecological Status Group II (ESG II) and Benthic Ecological Group II (BEG II), according to their ecological characteristics. Ecological quality status (EQS) was evaluated using EEI-c and BEARI, while Bray–Curtis similarity analysis and Principal Component Analysis (PCA) were applied to examine spatial patterns and relationships with environmental variables. The EEI-c assessment classified 19 stations as “high” and five stations as “good”, whereas only İzmir-Bostanlı exhibited “bad” ecological status. According to BEARI, five stations were classified as “high”, 17 as “good”, and Çandarlı, Güllük, and İzmir-Bostanlı as “moderate”, “poor”, and “bad”, respectively. A significant relationship was detected between EEI-c and BEARI values (R2 = 0.71). In addition, Macroalgae-Land Use Simplified Index (MA-LUSI) values were negatively correlated with both EEI-c and BEARI, indicating the sensitivity of macroalgal indices to anthropogenic pressures. Overall, the results demonstrate that macroalgae-based indices provide reliable tools for ecological assessment and support multi-metric approaches in coastal monitoring programs. This study provides one of the first comparative evaluations of destructive (EEI-c) and non-destructive (BEARI) macroalgal indices in relation to MA-LUSI pressure assessment along the Turkish Aegean coasts.