02297naa a2200169 a 450000100080000000500110000800800410001910000110006024500810007126000090015252017240016165300250188565300170191065300190192765300270194677301540197310812372011-10-13       1995    bl uuuu     u00u1 u    #d1 aEpagri  aBioeconomic study of fish production on polyculture systems on South Brazil.  c1995  aThe main objective of this research was to evaluate the main bioeconomic constraints in low intensity fish production systems used by small farmers in Santa Catarina (South Brazil). To do so, we compared fish production, fish productivity and economic results of three polyculture experiments involving seven combinations of species and three forms of supplementary feedstuffs (1 - a "cake" of agricultural by-products, 2 - green grass and 3 - animal manure). After 210-225 culture days the species reached a close range for total biomass varying between 2400 and 3077 kg/ha (average 2554 kg/ha). The highest final biomass was obtained in experiment 1, when tilapia (Oreochromis niloticus), common carp (Cyprinus carpio), grass carp (Ctenopharingodon idella) and pacu (Piaractus mesopotamicus) were stocked at 2900, 1700, 800 and 850 ind./ha, respectively. Despite the use of agricultural by-products, average unit production cost for experiment 1, 2 and 3 were high, around 1.63, 1.04 and 0.80 per kg, respectively. Major cost components were fixed cost of digging the ponds and the (variable) cost to prepare the feed. Investment would not be recovered in any of the tested conditions after 5 years of fish culture. Some additional investigations on fish mixes through linear programming indicated a maximal increase of 14% on farmers income through species combination optimization. Our main conclusion was that low intensity production systems are not profitable in general. Techniques for achieving higher productivity levels are also needed to pay for the high fixed costs of the activity. Market prospects for cultivated fish in Southern Brazil seem to be improving, but more research is needed in this area too.  aAgricultura familair  aPiscicultura  aSanta Catarina  aSistema de policultivo  tIn: SUSTAINABLE AQUACULTURE 95, ., 1995, Honolulu, Hawaii, EUA. Proceedings... Honolulu, HI: Pacific Congress on Marine Science and Technology, 1995.