ASSESSMENT OF WATER POLLUTION STRESSORS ON AQUATIC BIODIVERSITY AND FISH PHYSIOLOGY IN CULTURED AND NATURAL HABITATS

Abstract

Water pollution stressors pose significant challenges to fish health and aquatic ecosystem sustainability, particularly in systems exposed to dynamic environmental conditions. This study assessed the effects of key water quality stressors on fish physiology and aquatic biodiversity risk in a cultured tilapia (Oreochromis niloticus) system using a high-resolution, time-series analytical approach. A monitoring dataset downloaded as an Internet-of-Things (IoT)-based data consisting of 4,383 hourly observations was examined to define the nature of the temporal variability in the temperature, dissolved oxygen, pH, and turbidity and assess how these variables relate to fish growth, survival, and disease occurrence. Findings showed that water quality stressors experienced chronic exposure regimes, and not short-term changes, which highlighted the significance of cumulative effects of stress. Growth and survival in the temperature and dissolved oxygen ranges were positively related, whereas turbidity was always negatively related with physiological performance. A stressor-based habitat suitability proxy also identified times of high biodiversity risk which is associated with long term turbidity and oxygen stress. The results prove the relevance of continuous monitoring in the identification of chronic stress processes and point to turbidity as an important factor affecting the productivity and ecological integrity.