Flathead grey mullet - Fertilizers and fertilization

M. Cephalus can be cultured extensively. Valliculture is widely practiced in bays and lagoons along the Adriatic coast of Northern Italy to produce mullet (James et al., 1985). However, the mullet is commonly reared under semi-intensive condition, within fertilized ponds.

Ghion (1986) reported that 1 tonne/ha of one year old flathead grey mullets were produced in a 4 ha pond adding 18 tonnes of organic matter during the overall season and tilling the bottom every 15 days in order to put the sediment nutrients in suspension. Suggested fertilization guides are presented in Table 3. Organic and inorganic fertilizers are often used in conjunction in Egypt. Garg et al. (2006) recommended a dosage of 7 500 kg/ha/year of cow dung along with supplementary feeding for obtaining high productivity in inland saline water ponds with salinity levels ranging between 13 and 21 parts per thousand.

Effluent removal
Several publications have tackled the interest of M. cephalus for ameliorating the fish farms effluents and the resulting enriched sediments.

While foraging for food, the fish resuspend detritus, increase the oxygen supply to the benthos, and oxygenate buried organic matter (Katz et al., 2002). In an experiment, the removal efficiency of fish farm effluents was estimated to be of 4.2 g C, 0.7 g N and 7.5 mg P/kg mullet/m2/day (Angel et al., 2003). However, Erler et al. (2004) stated that the culture of flathead grey mullet alone in shrimp farm effluent treatment systems does not result in significant retention of N but can contribute to the control of macroalgal biomass.