EMISSION CHARACTERISTIC AND INFLUENCING FACTOR OF CO₂, CH₄, AND N₂O FROM WATER-AIR INTERFACE OF LARGEMOUTH BASS CULTURE POND

Largemouth bass (Micropterus salmoides) has become one of the important species cultured in ponds across China, yet there are few studies on greenhouse gas fluxes at the water-gas interface in largemouth bass culture ponds. In this study, we investigated the characteristics and patterns of greenhouse gas emissions in largemouth bass culture ponds located in Daye City, Hubei Province. The CO₂, CH₄, and N₂O emission fluxes at the water-air interface were measured by static box-gas chromatography from July to October 2023. Additionally, we analyzed the main influencing factors by examining changes in surface environmental factors and nutrients levels. The results showed that the mean emission fluxes of CO₂, CH₄, and N₂O at the water-air interface of the largemouth bass culture ponds were 241.0±14.5, 1.38±0.31, and 0.24±0.04 mg/m²·h during the monitoring period, respectively, indicating that the largemouth bass culture ponds are a net source of greenhouse gas emission. Pearson correlation analysis showed that CO₂ emission fluxes were positively correlated with WT, T, Chl.a, P, and pH, and negatively correlated with \rmNH^+_4 -N. N₂O emission flux was positively correlated with TN, \rmNO^-_2 -N, \rmNO^-_3 -N, and DO, and negatively correlated with WT. No significant correlation was found between CH₄ emission flux and environmental factors. Redundancy analysis indicated showed that WT is the key environmental factor affecting the emission of CO₂, CH₄, and N₂O at the water-air interface. During the 90-day growth cycle, the 100-year global warming potential of largemouth bass aquaculture pond was 7.74×10³ kg/hm², suggesting that pond culture of largemouth bass may have the potential to promote the greenhouse effect.