International cooperation in evaluation of environmental

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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

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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

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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

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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

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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

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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

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Tilapia - shrimp polyculture
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Philippines - Early adoption of polyculture

• Severe disease outbreaks in shrimp industry in
  1990s
• 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

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Tilapia-shrimp farm in Sonora, Mexico
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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

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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

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Tilapia production in Ecuador and shrimp viral
infections
White Spot
Taura
IHHN
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Red strains of tilapia most popular for brackish
polyculture systems
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• Tilapia production in outside ponds with shrimp
  in covered ponds

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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

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Thailand experimental polyculture systems at AIT

• Shrimp survival - 90
• Shrimp yield - 3,000 kg/ha
• Tilapia survival - gt 90
• Tilapia yield - 1,500 kg/ha
• Tilapia growth - 10g to 300g in 10 weeks
• Shrimp survival and yield was lower in
  monoculture control

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US Shrimp-Tilapia polyculutre

• Tilapia production in supply reservoirs
• Condition water before shrimp

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Tilapia in supply reservoir
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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

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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.

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Conclusions

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

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Thank you for your interest

• Research support provided by the Pond
  Dynamics/Aquaculture CRSP
• Questions ????