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Effects of lining and drying on the chemical composition of sediments and influence of organic carbon on carp growth in aquaculture ponds
Author(s) -
Kassila J
Publication year - 2003
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1046/j.1365-2109.2003.00822.x
Subject(s) - mineralization (soil science) , carp , environmental chemistry , total organic carbon , phytoplankton , organic matter , fractionation , aquaculture , biology , zoology , chemistry , ecology , nutrient , fishery , fish <actinopterygii> , organic chemistry , soil water
Chemical characteristics and P‐fractionation of sediments from the Deroua fish culture farm (Beni Mellal, Morocco) were analysed in 1998 and 1999. The high concentrations of organic N and organic C in the sediments reflect the high productivity of phytoplankton in the lined ponds. Despite the fact that these ponds were not frequently fertilized, inorganic P was more important in the sediments. The P released from CaCO 3 ≈P was the principal source of P for phytoplankton. The mineralization rate of organic C during the drying period was about 87 µg g −1 day −1 in the sediments. The mineralization rate of organic N seems to be less, compared with organic C. The experimental results indicate that the C:N ratio and texture of sediments could explain the immobilization of organic N. All forms of P remained almost unchanged after the drying period except for Fe(OOH)≈P. The ferric (oxy) hydroxides protect NaOH ext ‐P from the bacterial lyses and stabilize therefore their concentration. The inorganic P represented about 88% of Total P in the sediments and may influence the mineralization rate of organic P. The growth of silver carp were reduced in presence of high concentrations of organic C in sediments (> 30 mg/g). Compounds toxic to fish such as Fe 2+ , Mn 2+ , H 2 S and CH 4 were then released in the water column.