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

shrimp polycultures

Remedios Bolivar, Yang YiWilfrido Contreras, Kevin Fitzsimmons

Aquaculture CRSP

US Aquaculture Meetings

Feb. 20, 2003

IntroductionMore efficient use of resources (water, land,

feed, labor, etc)Shrimp and tilapia are two of the most

important aquaculture productsThey share many ecological characteristics,

polyculture worldwideFarm experience suggest benefits to polycultureOpportunity to restore abandoned farms

IntroductionConducted survey in Thailand, Vietnam,

Mexico, the Philippines and the US.Followed with field trials in Thailand

and MexicoPreliminary lab studies support field

reportsSurvival and growth rates improved

Reported benefitsReduction in levels of pathogens (green

Vibrios and viral infections)Fish reduce accumulation of wastes in

production unitsFish encourage beneficial algal bloomsTilapia consume potential disease

vectors, especially crustacea

Reported benefitsBring disease ravaged farms back into

productionLower density, less technology intensiveFish can be sold into local markets to

improve domestic food supplyDisplaced social groups may be able to take

advantage of abandoned farms

Several modelsTilapia in cages in shrimp pondTilapia in supply reservoirsTilapia and shrimp loose in pondTilapia and shrimp in crop rotationTilapia to treat/re-use shrimp

effluent

Tilapia - shrimp polyculture

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

Tilapia-shrimp farm in Sonora, Mexico

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

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 infrastructureExporting tilapia to US and EU

Tilapia production in Ecuador and shrimp viral infections

TILAPIA PRODUCTION IN ECUADOR

0

5,000

10,000

15,000

20,000

25,000

30,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Year

Pro

du

ctio

n (

mt)

IHHN TauraWhite Spot

Red strains of tilapia most popular for brackish polyculture systems

Tilapia production in outside ponds with shrimp in covered

ponds

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

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

US Shrimp-Tilapia polyculutre

Tilapia production in supply reservoirs

Condition water before shrimp

Tilapia in supply reservoir

Arizona resultsAverage 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}

ConclusionsPolyculture 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.

ConclusionsTilapia in supply reservoirs most

commonCage culture of tilapia in shrimp

pondCrop rotation of tilapia after

shrimp disease outbreaks

Thank you for your interestResearch support provided by the

Pond Dynamics/Aquaculture CRSP

Questions ????