Physicochemical and microbiological assessment of oyster farms in Ilocos Sur, Philippines

Oyster farming in the Philippines plays a crucial role in the livelihoods of local communities, particularly in rural coastal areas of Ilocos Sur. However, the industry faces environmental degradation, limited market demand, and a prolonged cultivation period, which hinder its profitability and sustainability. This study evaluated the physicochemical and microbiological quality of water in six selected oyster farms using standardized analytical techniques. Surface water samples were collected and analyzed for temperature, pH, turbidity, total coliforms, and fecal coliforms. Physicochemical parameters were measured using the SPARK Science Learning System, while microbial quality was assessed through multiple tube fermentation technique. Results indicate that the temperature range from 28.1 to 30.1°C and pH levels of 7.56 to 7.79 obtained from all farms are within the DENR standards and suitable for oyster culture. However, turbidity in most farms exceeded the permissible level of 5 NTU, which is dangerous for oyster health. More importantly, many of these farms' fecal and total coliform counts are alarming, far higher than the DENR standard of 70 MPN/100 mL. The conditions are generally suitable for oyster farming. However, special attention is required concerning water turbidity and microbial contamination. These factors have related implications for such farms' sustainability and the harvested oysters' safety. Regular water quality monitoring, farm management improvement practices, community education for environmental protection measures, and strict enforcement of regulation measures against potential contamination risks are recommended.