International cooperation in evaluation of environmental & economic impacts of tilapia-shrimp polycultures

1. International cooperation in evaluation of environmental & economic impacts of tilapia-shrimp polycultures Remedios Bolivar, Yang YiWilfrido Contreras, Kevin FitzsimmonsAquaculture CRSP US Aquaculture Meetings Feb. 20, 2003

2. Introduction • More efficient use of resources (water, land, feed, labor, etc) • Shrimp and tilapia are two of the most important aquaculture products • They share many ecological characteristics, polyculture worldwide • Farm experience suggest benefits to polyculture • Opportunity to restore abandoned farms

3. Introduction • Conducted survey in Thailand, Vietnam, Mexico, the Philippines and the US. • Followed with field trials in Thailand and Mexico • Preliminary lab studies support field reports • Survival and growth rates improved

4. Reported benefits • Reduction in levels of pathogens (green Vibrios and viral infections) • Fish reduce accumulation of wastes in production units • Fish encourage beneficial algal blooms • Tilapia consume potential disease vectors, especially crustacea

5. Reported benefits • Bring disease ravaged farms back into production • Lower density, less technology intensive • Fish can be sold into local markets to improve domestic food supply • Displaced social groups may be able to take advantage of abandoned farms

6. Several models • Tilapia in cages in shrimp pond • Tilapia in supply reservoirs • Tilapia and shrimp loose in pond • Tilapia and shrimp in crop rotation • Tilapia to treat/re-use shrimp effluent

7. Tilapia - shrimp polyculture

8. Philippines - Early adoption of polyculture • Severe disease outbreaks in shrimp industry in 1990’s • Major producer of tilapia • Developed tilapia-shrimp polyculture system on Negros Island • Crop-rotation, tilapia in cages, and tilapia in reservoir • Have been operating for 6 years

9. Tilapia-shrimp farm in Sonora, Mexico

10. Tilapia - shrimp polyculture in Mexico • Tilapia-shrimp polyculture in full seawater • Effluent from shrimp goes to tilapia • Tilapia consume uneaten feed, fecal strands, macro-algae and reduce organic matter levels in effluent • Additional experimental trials being conducted at Autonomous University of Tabasco, survey in Sinaloa

11. Tilapia-shrimp production in Ecuador and Peru • Supplementing shrimp because of white spot and other shrimp diseases • Crop rotation, tilapia in supply reservoirs • Using shrimp infrastructure • Exporting tilapia to US and EU

12. Tilapia production in Ecuador and shrimp viral infections WhiteSpot Taura IHHN

13. Red strains of tilapia most popular for brackish polyculture systems

14. Tilapia production in outside ponds with shrimp in covered ponds

15. Thailand farm-based polyculture systems • Tilapia in cages in shrimp ponds • Tilapia in sequential polyculture before and after shrimp ponds • Farmers testing impacts on microflora

17. Thailand experimental polyculture systems at AIT • Shrimp survival - 90% • Shrimp yield - 3,000 kg/ha • Tilapia survival - > 90% • Tilapia yield - 1,500 kg/ha • Tilapia growth - 10g to 300g in 10 weeks • Shrimp survival and yield was lower in monoculture control

18. US Shrimp-Tilapia polyculutre • Tilapia production in supply reservoirs • Condition water before shrimp

19. Tilapia in supply reservoir

20. Arizona results • Average tilapia yield - 2,400 kg in 0.04 ha ponds (eight months) {60,000 kg/ha} • Average shrimp yield - 2,000 kg in 0.1 ha ponds (five months) {20,000 kg/ha}

21. Conclusions • Polyculture with shrimp will become common in most shrimp farming areas • Already practiced in Thailand, Philippines, Vietnam, Mexico, US (Arizona and Florida), Ecuador, Peru, Eritrea. Will expand.

22. Conclusions • Tilapia in supply reservoirs most common • Cage culture of tilapia in shrimp pond • Crop rotation of tilapia after shrimp disease outbreaks

23. Thank you for your interest • Research support provided by the Pond Dynamics/Aquaculture CRSP • Questions ????