Economic Viability of Polyculture of Nile Tilapia and Australian Redclaw Crayfish in Yucatan State, Mexico

Tilapia culture in rural communities of the state of Yucatan, Mexico, has been increasing in recent decades. Polyculture of tilapia with other more commercially valuable species is an opportunity to substantially improve the economic yields of rural producers. The economic viability of implementing a Nile tilapia with Australian redclaw crayfish polyculture was analyzed using profitability indicators such as internal rate of return (IRR) and net present value of the investment (NPV). A bioeconomic model was developed to simulate three production densities (33/0, 33/20, tilapia and crayfish, respectively), accounting for investment recuperation in time horizons of 5, 10 and 15 years. The model includes a biological sub-model describing the growth of both organisms, a management sub-model that influences organism development and an economic sub-model describing the main input and output variables of the economic setting of tilapia producers in the state of Yucatan. The biological sub-model was parameterized using published experimental polyculture data from Israel. A thermal correction function was integrated into Von Bertalanffy’s growth model to include the effect of temperature of Yucatan on growth in both organisms. The simulations showed a notable improvement in profitability when farms adopt the polyculture strategy, particularly over the 5-year horizon. The NPV of this horizon was -$4,855.06, $7,923.33 and $1,519.88, Mexican pesos, to the tilapia monoculture, medium crayfish density polyculture and high crayfish density polyculture, respectively. The Nile tilapia with Australian redclaw crayfish polyculture shortens investment recuperation time and it inhibits the risk related to changes in tilapia sale price. The best of the three studied combinations was the medium crayfish density polyculture (33/10) in all time horizons.