Abstract
Mingachevir Reservoir is the principal regulating water body of Azerbaijan’s Middle Kura cascade, yet much of its hydroecological evidence remains dispersed across legacy monitoring tables and local studies. This paper consolidates station-level microbial observations, nutrient records, spatial hydrochemical measurements and major-ion profiles reported in a 2023 master’s dissertation, recalculates internally inconsistent summary values from the underlying station data, and interprets the historical baseline against recent Kura River research published in 2025. Seasonal mean microbial abundance was higher in 2015 than in 1982 in all four seasons, with the largest relative difference in winter (68%). Nutrient records for 1987–2009 indicated pronounced enrichment episodes, particularly for nitrite and phosphorus, although differences in historical analytical protocols require cautious interpretation. Along the Shikhli–Salyan transect, the mean sum of major ions declined through the reservoir cascade, reaching its lowest value at Mingachevir (approximately 560 mg L−1), before increasing downstream to approximately 1,066 mg L−1 at Salyan. Within-reservoir contrasts showed lower transparency and higher mineralization, chloride and iron near the dam zone. Recent studies confirm that mineralization and microbial contamination remain relevant concerns in the Kura system. The combined evidence supports a risk-based monitoring design integrating seasonal field sampling, microbial indicators, nutrients, major ions and satellite-supported observations. The paper provides a transparent historical benchmark rather than claiming contemporary field status.