Integrated production of crayfish and rice: a management model

The introduction of the Louisiana Red Swamp Crayfish is another example of a non-native species causing damage to the natural balances within a region. In the Mondego river valley (Northern Portugal) the species is considered a pest and is assumed to cause considerable damage to the rice production due to burrowing. Up to now, it has been treated with xenobiotic chemicals. This is undesirable since the species is also used as human food source and it is of economical importance to the region. Modelling has been applied as a ecotechnological tool to identify future strategies for the simultaneous harvesting of both rice and crayfish within the same fields. The available data indicates that a restocking program is needed in order to maintain population numbers from year to year when crayfish are harvested or a surfactant is used to reduce crayfish activity. The development of the model is included in the scope of a general project with the goal to reduce damages in the rice fields and to implement crayfish production.