Lionel Dabbadie

The Tanjona from Fenoarivo: Integrated fish farming systems in Madagascar

Fig. 3: Fenoarivo’s Tanjona, 1963 Results: 27 fish farmers were counted from Tanjona of Fenoarivo in 2016 Two typologies were identified (Fig. 4): 1) Tanjona with fish farming in ponds and culture on dykes 2) Tanjona with rice-fish aquaculture and culture on dykes Polyculture (carp, tilapia, snake head fish) Cycle of 6 to 12 months Fish stocking from caught in the neighbouring Sisaony Swamp or from rice plots Fish production: Study case: M. Dàdà is a farmer/fisherman from Fenoarivo. He own 12 rice plots of 0.76 ha, 3 Tanjona of 0.15 ha associated to oranges, leaves and sweet potatoes of which one is dedicated to fish farming (0.10 ha). He raises ducks and makes bricks every year. Fishing and fish farming: • Fish farming is realized on a pond (0.04 ha) • Fish stocking occurs from is own fishing activity (Nov. to May) • Fish are fed every 15 days with rice bran, maize, leaves, sweet potatoes and cow skin • Fertilization result from crops watering runoff • Fish production is about 300 kg/yr with a growth of 30 kg • Total fish growth is 714 kg/ha/cycle Synthesis of economical performances for each activity (Fig. 5):

Characterization of freshwater fish quality in the Tanjona surrounding Antananarivo: Utilization of trace metals and stables isotopes (δ13C & δ15N)

AMPIANA project: feed Antananarivo population, capital of Madagascar, with fish. Tanjona: innovative semi-extensive fish farming model identified in the project, located in floodplains of Fenoarivo city and the surrounding of Antananarivo. Urbanization and population growth may affect water quality in these floodplains and health quality of fish reared in this system (Fig.1). What is the health quality of water and fish from this system? The aims of this study was therefore to characterize the level of water contamination in the Tanjona via trace metals concentrations and stables isotopes (δ13C & δ15N) in white muscle of tilapia, as well as stables isotopes in particulate organic matter and sediments.