Constant Dissolved Oxygen Concentration Research Articles

Growth and Survival of Channel Catfish and Yellow Perch Exposed to Lowered Constant and Diurnally Fluctuating Dissolved Oxygen Concentrations

Abstract Growth and survival were determined for duplicate lots of juvenile channel catfish (Ictalurus punctatus) and yellow perch (Perca flavescens) exposed for 69 and 67 days, respectively, to nearly constant dissolved oxygen (DO) concentrations at near air saturation (control), 6.5, 5.0, 3.5, and 2.0 mg/L. The following year juveniles of the same species were exposed to DO concentrations that gradually fluctuated diurnally at about 1.0 to 1.5 mg/L above and below the constant lowered DO levels of the previous year. At mean constant DO concentrations of 3.5 mg/L or less, channel catfish consumed less food and growth was significantly reduced (P = 0.05). Growth was not impaired by mean fluctuations of about 6.2 to 3.6 and 4.9 to 2 mgL, but was significantly reduced at fluctuations of about 3.1 to 1.0 mg/L. Similarly, at mean constant DO concentrations near 3.5 mg/L, yellow perch consumed less food but growth was not affected; at 2.0 mg/L less food was consumed and growth was significantly reduced (P = 0....

Effect of Long-term Reduction and Diel Fluctuation in Dissolved Oxygen on Spawning of Black Crappie, Pomoxis nigromaculatus

Abstract Mature black crappies were exposed over winter in the laboratory to constant dissolved oxygen concentrations near 2.5, 4.0, 5.5, and 7.0 mg/liter. Starting on 26 April during a simulated spring-to-summer rise in water temperature, some were continued at the original oxygen concentrations while others were subjected to mean diel fluctuations ranging from 0.8 to 1.9 mg O2/liter above and below the original concentrations. Controls were maintained at concentrations near air saturation. No spawning occurred at the lowest fluctuating treatment of 1.8 to 4.1 mg/liter. This treatment also caused behavioral aberrations as the water temperature reached 20 C. Successful spawning occurred during all other treatments.

Chronic Effects of Low Dissolved Oxygen Concentrations on the Fathead Minnow (Pimephales promelas)

Fathead minnows were exposed to constant dissolved oxygen concentrations (1.0–5.0 mg/liter) for 11 months. The number of eggs produced per female was reduced at 2.0 mg/liter; no spawning occurred at 1.0 mg/liter. Fry growth was reduced significantly at all concentrations below the control (7.9 mg/liter). Fry survival was reduced at 4.0 mg/liter and lower dissolved oxygen concentrations; 18% of the survivors at 4.0 mg/liter were deformed. The time required for hatching was increased at successively lower oxygen concentrations by as much as 50% (from 5.0 under control conditions to 7.8 days at 2.0 mg/liter), but no effect on percentage hatch was observed.

A System for Maintaining Constant Dissolved Oxygen Concentrations in Flowing-Water Experiments

A System for Maintaining Constant Dissolved Oxygen Concentrations in Flowing-Water Experiments

Influence of Oxygen Concentration on the Growth of Juvenile Largemouth Bass

Experiments are reported on the influence of nearly constant dissolved oxygen concentrations, both below and above the air-saturation level, and of wide diurnal fluctuations of oxygen concentration on the appetite, growth, and food conversion efficiency of juvenile largemouth bass, Micropterus salmoides (Lacépède). The experimental apparatus used was designed to provide constant flows of water at 26 C and with controlled oxygen content through 12-gal (45-liter) bottles each containing 10 test fish. The fish were fed unrestricted rations of small, live earthworms throughout the six experiments, whose duration was usually 15 days.The growth rates and food consumption rates of the bass increased markedly with increase of the constant oxygen concentrations to levels near the air-saturation level, and declined with further increase of oxygen concentrations. Gross food conversion efficiencies were considerably reduced only at concentrations well below 4 mg/liter.The growth of bass subjected alternately to low and higher oxygen concentrations for either equal or unequal portions of each 24-hr day was markedly impaired. It was almost always less than that which presumably would have occurred had the fish been held at a constant concentration equal to the mean, either arithmetic or geometric, of the higher and lower concentrations to which the fish had been exposed.