Present status of water quality management practices of ornamental fish farms in Galle district, Sri Lanka

Abstract

This study assessed the current water quality management practices of medium-scale ornamental fish farms in the Galle district, Sri Lanka, investigated the major barriers to effective management and explored potential improvement strategies. Data were collected through a structured questionnaire from 33 randomly selected farms registered under the National Aquaculture Development Authority (NAQDA). Data were analyzed using Microsoft Excel (2021) and the chi-square test. Results showed that 60.61% of the farms did not monitor water quality on-site. Common water quality issues, including pH imbalances (54.90%) and low dissolved oxygen levels (19.61%), directly impact fish health and mortality. For immediate water quality improvement, partial water exchanges and enhanced aeration were employed. Long-term strategies included regular monitoring, substrate siphoning, and bioremediation using aquatic plants (Pandanus amaryllifolius, Eichhornia crassipes, Vallisneria, Pistia etc.) and natural water conditioning using leaves (Terminalia catappa, T. arjuna, Musa paradisiaca). Most farmers depended on traditional treatment methods, such as salt dips (43.08%) for managing fish diseases. Notably, 93.94% of farms directly disposed wastewater into the environment without treatment, raising concerns about environmental sustainability. A significant correlation was observed between monthly income and on-site water quality measurement practices (p < 0.05). The main barriers to effective water quality management were identified as a lack of resources and high equipment costs. Ornamental fish farmers suggested that water quality management practices could be improved through the adoption of advanced treatment technologies, access to loans and enhanced support from government agencies and relevant institutions.