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Production Responses of Channel Catfish to Minimum Daily Dissolved Oxygen Concentrations in Earthen Ponds
Author(s) -
Torrans Eugene L.
Publication year - 2008
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a07-102.1
Subject(s) - zoology , aeration , alkalinity , catfish , total suspended solids , oxygen , oxygen saturation , ictalurus , secchi disk , biology , water quality , saturation (graph theory) , biochemical oxygen demand , chemical oxygen demand , environmental science , fishery , environmental engineering , chemistry , ecology , fish <actinopterygii> , wastewater , nutrient , mathematics , eutrophication , organic chemistry , combinatorics
This study determined the effects of the minimum daily dissolved oxygen (DO) concentration on the production parameters of channel catfish Ictalurus punctatus in earthen ponds. Fifteen 1‐acre ponds (five ponds per treatment) were managed as high‐oxygen (minimum DO concentrations averaging 4.37 ppm or 54% air saturation from June through September), medium‐oxygen (minimum DO concentrations averaging 2.68 ppm or 33.2% air saturation), or low‐oxygen treatments (minimum DO concentrations averaging 2.32 ppm or 28.7% air saturation) using one 5‐hp electric paddlewheel aerator per pond. Fish in the high‐, medium‐, and low‐oxygen treatment ponds were fed a mean total of 14,008, 13,212, and 12,607 lb/acre of 28%‐protein floating feed, respectively. Net production paralleled the total amount of feed fed, averaging 5,772, 5,278, and 5,113 lb/acre in the high‐, medium‐, and low‐oxygen treatments, respectively. Individual fish weight at harvest also showed a similar trend, averaging 1.37, 1.33, and 1.30 lb in the high‐, medium‐, and low‐oxygen treatments, respectively. No visible stress responses were observed in any ponds during this study. Total aeration averaged 5,245, 2,518, and 1,337 hp‐h/acre in the high‐, medium‐, and low‐oxygen treatments, respectively. Treatments with higher minimum DO concentrations had significantly higher nitrite‐nitrogen, suspended solids, chlorophyll a , and pH and lower Secchi disk visibility, alkalinity, and hardness; however, no water quality parameters exceeded the normal acceptable range for channel catfish. While the cost of electricity must be considered, maintaining a minimum daily DO concentration of 2.3–2.5 ppm is suggested as a compromise between maximizing both the amount of feed fed and fish production while minimizing aeration costs.