Performance of alternative experimental strategies for developing extensive polyculture systems in small water bodies

One approach to improving management that appears to have potential for culture based fisheries is adaptive learning. Adaptive learning approaches seek to either use existing contrasts between management actions, or deliberately choose management actions, such as species stocked and/or stocking density, that create contrast. The contrast provides an opportunity to compare between waterbodies that have been subject to different strategies and learn more about the underlying processes. Learning about these processes can reduce the uncertainty associated with management and potentially improve both predictions and outcomes. Enhancements in small water body fisheries are typically characterized by two factors that have major implications for the application of experimental management regimes:

• Most are managed as polyculture, or multi-species stocking systems. Quantifying inter-specific interactions is crucial to the optimisation of such systems.
• Small water bodies are replicated systems. Experiments can be carried out on a representative sample of water bodies with an appropriate degree of replication, and the knowledge gained can justifiably be generalized to the whole population of water bodies.

In this study, a mathematical model was used to explore the use of experimental stocking strategies applied to polyculture systems in replicated small water bodies, and their ability to improve predictions and outcomes.