Progress 07/01/00 to 06/30/05
Outputs
Sediment depth and organic carbon concentration were measured in sediment cores from 45 commercial catfish ponds in NW MS, April-September in 1998 and 1999. Ponds had been in continuous catfish production from 14 days to 21 years. Sediment depth was 1 to 95 cm and was heterogeneously distributed within ponds: least in the shallow end (26.3 cm) and greatest in deeper areas (33.7 cm). Mean sediment depth increased with pond age, although the rate of sediment accumulation was greatest in the first year (12.5 cm/y). Despite large inputs of organic matter, sediment organic carbon concentrations did not increase with pond age. Sediment oxygen demand (SOD) measured in 45 commercial catfish ponds in NW MS ranged from 63 to 1,038 mg/m2 per h. Nine variables were selected and measured to assess their relative importance in accounting for variation in SOD. Six variables were included in multiple regression models that explained slightly more than half of the variation in SOD:
dissolved oxygen concentration at the beginning of respirometry incubation, particulate organic matter concentration in water over the sediment surface, organic carbon concentration in the upper 2 cm of the sediment-water interface, organic carbon concentration in the underlying mature sediment layer, water temperature, and depth of accumulated sediment. Sediment oxygen demand was most sensitive to changes in dissolved oxygen concentration in the overlying water, particulate organic matter concentration in the water, and the concentration of organic carbon in the upper sediment layer. Maintaining aerobic conditions at the sediment-water interface will minimize accumulation of organic matter in pond sediment. Seven multiple regression models predicting SOD and values of corollary measurements of the important factors affecting SOD in commercial catfish ponds were used to estimate industry-wide SOD (SODi). Relative respiration rates of sediment, plankton, and fish were calculated as
proportions of total respiration for pond water depths ranging from 0.25 to 4.00 m. Although whole pond respiration increased as pond depth increased, the proportion of total respiration represented by sediment decreased from 38% to 10%. Increasing pond depth increases the total mass of DO available for all respiration, and nighttime DO concentrations will decline at a slower rate, reducing the need for supplemental aeration. The accumulation of sediment organic matter can be minimized by increasing the DO concentration at the pond bottom by aeration, mixing, and pond construction that aligns the long axis of ponds parallel with prevailing summer winds to maximize mixing potential. Because pond water volume decreases over time from sediment accumulation, annual aeration costs will increase with pond age. Constructing ponds with greater initial depth will therefore reduce long-term cost of aeration, allow more flexible management of pond water, and reduce the long-term expense
associated with pond reconstruction. Project has been discontinued due to departure from MSU of principle investigator.
Impacts
The results of this study indicate that sediment oxygen uptake in channel catfish ponds occurs at a much higher rate than previously reported. The results also reinforce the importance of maintaining adequate oxygen concentrations at the pond bottom to minimize sediment organic matter accumulation. The magnitude of sediment accumulation suggests that ponds should be constructed or re-constructed with greater operational depth (at least 2 m) if ponds will be operated for long (15-20 yr) periods without draining.
Publications
- Steeby, J.A., J.A. Hargreaves, and C.S. Tucker. 2004. Factors affecting sediment oxygen demand in commercial channel catfish ponds. Journal of the World Aquaculture Society 35:322-334.
- Steeby, J.A., J.A. Hargreaves, C.S. Tucker, and T.P. Cathcart. 2004. Modeling industry-wide sediment oxygen demand and estimation of the contribution of sediment to total respiration in commercial channel catfish ponds. Aquacultural Engineering 31:247-262.
- Steeby, J.A., J.A. Hargreaves, C.S. Tucker, and S.K. Kingsbury. 2004. Accumulation, organic carbon and dry matter concentration of sediment in commercial channel catfish ponds. Aquacultural Engineering 30:115-126.
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Progress 01/01/01 to 12/31/01
Outputs
A study was conducted to evaluate the factors affecting the rate of sediment oxygen uptake in commercial channel catfish ponds. In order of importance, dissolved oxygen concentration in the overlying water, particulate organic matter concentration in the water, and sediment carbon concentration in the surface sediment affected sediment oxygen uptake rate. A Monte Carlo simulation using a multiple regression model was used to predict whole-pond sediment oxygen uptake (470 mg oxygen/sq m/hr) in commercial channel catfish ponds during the summer. Sediment accumulation was measured in ponds from 0 to 21 yr of continuous production. Sediment accumulation rate was most rapid during the first 5 yr, representing displacement of easily eroded material from pond levees. After 5 yr, the sediment accumulation rate decreased. Mean sediment accumulation after 20 yr was approximately 40 cm. Sediment accumulation reduces operational pond depth, thereby reducing water storage capacity
and increasing the effect of the sediment on water quality. Sediment oxygen uptake can account for 21 to 38% of pond respiration, the proportion increasing as pond depth decreases.
Impacts
The results of this study indicate that sediment oxygen uptake in channel catfish ponds occurs at a much higher rate than previously reported. The results also reinforce the importance of maintaining adequate oxygen concentrations at the pond bottom to minimize sediment organic matter accumulation. The magnitude of sediment accumulation suggests that ponds should be constructed or re-constructed with greater operational depth (at least 2 m) if ponds will be operated for long (15-20 yr) periods without draining.
Publications
- Han, F. X., Hargreaves, J. A., Kingery, W. L., Huggett, D. B., Schlenk, D. K. 2001. Accumulation, distribution, and toxicity of copper in sediments of catfish ponds receiving periodic copper sulfate applications. Journal of Environmental Quality 30:912-919.
- Steeby, J. A., Kingsbury, S., Hargreaves, J. A., Tucker, C. S. 2001. Sediment accumulation in commercial channel catfish production ponds. Global Aquaculture Advocate 4(3):54-66.
- Steeby, J. A., Kingsbury, S., Hargreaves, J. A., Tucker, C. S., Cathcart, T. and Zimba, P. 2001. Determination of production season sediment oxygen demand in commercial channel catfish Ictalurus punctatus grow-out ponds. Book of Abstracts - Aquaculture 2001, Lake Buena Vista, FL.
- Steeby, J. A., Kingsbury, S., Hargreaves, J. A., Tucker, C. S., Cathcart, T. and Zimba, P. 2001. Accumulation rate of sediment in commercial channel catfish Ictalurus punctatus grow-out ponds, with years of continuous use and recommended construction and management strategies. Book of Abstracts - Aquaculture 2001, Lake Buena Vista, FL.
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Progress 01/01/00 to 12/31/00
Outputs
A study was conducted to evaluate the factors affecting the rate of sediment oxygen uptake in commercial channel catfish ponds. In order of importance, dissolved oxygen concentration in the overlying water, particulate organic matter concentration in the water, and sediment carbon concentration in the surface sediment affected sediment oxygen uptake rate. A multiple regression model was used to predict whole-pond sediment oxygen uptake (439 mg O2 m-2 h-1) in commercial channel catfish ponds during the summer. Sediment accumulation was measured in ponds from 0 to 21 yr of continuous production. Sediment accumulation rate was most rapid during the first 5 yr, representing displacement of easily eroded material from pond levees. After 5 yr, the sediment accumulation rate decreased. Mean sediment accumulation after 20 yr was approximately 40 cm. Sediment accumulation reduces operational pond depth, thereby reducing water storage capacity and increasing the effect of the
sediment on water quality.
Impacts
The results of this study indicate that sediment oxygen uptake in channel catfish ponds occurs at a much higher rate than previously reported. The results also reinforce the importance of maintaining adequate oxygen concentrations at the pond bottom to minimize sediment organic matter accumulation. The magnitude of sediment accumulation suggests that ponds should be constructed or re-constructed with greater operational depth (at least 2 m) if ponds will be operated for long (15-20 yr) periods without draining.
Publications
- No publications reported this period
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