Decomposition of high protein aquaculture feed under variable oxic conditions.
The microbial decomposition of nitrogen-rich organic matter in aquaculture ponds is affected by the oxic-anoxic conditions gradient at the soil-water interface as well as by resuspension practices. To investigate these interactions, the decomposition of a 49% protein fish feed was analyzed in 10 marine lab-scale systems with different exposures to aerobic and anaerobic conditions. The degree of coupling between oxic and anoxic conditions in the system had a strong effect on product accumulation and loss from the culture system. Pure oxic or anoxic conditions proved to be less favorable than mixed aerobic-anaerobic systems with respect to the metabolites accumulated in the system. Short 15-min resuspension events and a continuous alternation of oxic and anoxic conditions at 12-h time intervals proved to be the best options to minimize the accumulation of organic matter in the systems. The correct coupling of aerobic-anaerobic conditions in space and time is a key to maintain a good water quality condition for the cultured animals and also to improve the decomposition and recycling of organic matter, reducing the environmental impact from the effluents.
Torres-Beristain
Beatriz
B
Aquaculture Culture and Fisheries Group, Wageningen Institute of Animal Sciences, P.O. Box 338, 6700 AH Wageningen, Wageningen University, The Netherlands. torres.beristain@gmail.com
Verdegem
Marc
M
Kerepeczki
Eva
E
Verreth
Johan
J
D000332:Aerobiosis; D000693:Anaerobiosis; D000821:Animal Feed / Q000032:analysis*; D017756:Aquaculture / Q000379:methods*; D001419:Bacteria / Q000378:metabolism; D004044:Dietary Proteins / Q000032:analysis*; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D012987:Soil; D014867:Water; D014874:Water Pollutants, Chemical
D004044:Dietary Proteins; D012987:Soil; D014874:Water Pollutants, Chemical; D014867:Water; D009584:Nitrogen; D010100:Oxygen