Can the Liquid Live Micro-Organisms System, a Commercial Probiotic, Affect Sediment, Water Quality, and Koi Carp Production in Fish Hatchery Ponds?

摘要

Sediment and turbidity can reduce pond and effluent water quality and fish production. We investigated the efficacy of a commercial bacterial product, Liquid Live Micro-Organisms (LLMO) System, in reducing sediment accumulation and improving water quality and fish production in hatchery ponds for 4.5 months. Four plastic-lined ponds received LLMO treatment at a rate of 1 L per 63,230 L of pond water at 2-week intervals throughout the study and additional twice-weekly applications during the last 6 weeks of the study. Another four ponds were untreated and served as the control. All ponds were cleaned of bottom sediments, supplied with plastic containers (33-34 containers/ha) to collect sediment samples, filled with water, and managed to control Prymnesium parvum ichthyotoxicity. Koi (a variant of the common carp Cyprinus carpio) were stocked into ponds as fry and were fed a commercial diet. Turbidity, Secchi disk visibility, chlorophyll a, pH, ammonia-nitrogen, suspended solids, carbonaceous biochemical oxygen demand, dissolved oxygen, and water temperature were monitored throughout the study. Sediment and fish production data were collected at the end of the study. Statistically, LLMO had no significant effect on sediment accumulation or any of the measured water quality variables and consequently had no effect on fish production. Our results did not support claims or reports that LLMO can reduce sediment accumulation or improve water quality and fish production. Two issues (small sample size and low LLMO application rate) may have confounded our results, thereby preventing us from making firm conclusions on the effects of LLMO on sediments, water quality, and fish production. We recommend that future studies be undertaken to address these issues.