Funnel-bottom smart pond engineering reduces dissolved inorganic nitrogen accumulation in intensive shrimp culture

Water-quality deterioration caused by feed waste and dissolved inorganic nitrogen (DIN) accumulation remains a major challenge in super-intensive shrimp farming. This study developed and field-tested an integrated smart pond engineering system for Pacific white shrimp ( Litopenaeus vannamei ) culture in southern Taiwan. The system combined continuous water-quality monitoring, underwater video-based feeding assessment, remotely controlled pond components, automated feeding support, and a funnel-bottom circular pond with central bottom discharge. A 114-day trial was conducted using a round concrete smart pond, while a rectangular pond stocked at the same density served as a conventional control. The funnel-bottom design helped concentrate feces, uneaten feed, and nitrogen-rich sludge toward the central discharge pipe for removal. Compared with the traditional pond, the smart pond showed lower mean nitrate, nitrite, and ammonium concentrations of 19.0, 4.8, and 6.9 μM, respectively, with a total DIN of 30.6 μM, whereas the traditional pond reached a total DIN of 272.6 μM. Shrimp in the smart pond also showed improved growth performance, suggesting more stable rearing conditions. Although the system improved monitoring and reduced some routine management demands, it required higher equipment investment and did not reduce unit production cost in this pilot-scale trial. These results suggest that integrated pond engineering, sensor-based monitoring, video-assisted feeding assessment, and targeted bottom discharge can improve nitrogen-waste management in intensive shrimp culture.