For each of these species a range of assumptions are required to populate values in the model that are used in the computation of outcomes. Although not an exhaustive list the assumptions include:
The models have been built by a detailed consideration of every culture step, inputs (costs) at each step and the likely outcomes (fish produced) from each stage and their likely selling price. The structure of the models should be considered as a framework within which to test the outcomes (level of profitability) when the assumptions are manipulated to reflect the particular situation of a specific aquaculture operation. The models also allow the user to test more extreme and risky scenarios to test the sensitivities and robustness of the potential project. This will assist in determining which factors are the most important to achieving a commercially successful operation.
The assumptions supplied with the models are based on the best available information that NPFL can obtain from commercial operators, researchers (published papers), experts and Government. Depending on the species, location, operator/owner and the choice of a range of management strategies – many assumptions may change significantly for any specific aquaculture operation. Each prospective owner/operator must check their assumptions very carefully to ensure they match the specific situation of their intended operations.
NPFL recommends that not only should expected parameters be entered when using the model to give an indication of likely success but poor results should also be modelled to demonstrate how badly things can go if certain assumptions are not achieved. In aquaculture, experience shows that at least initially there can be a period when expectations are not realised, there are numerous examples of this.
The modelled outputs will only be as good as the information added or manipulated in them as assumptions. NPFL does not suggest or imply that the assumptions used in the models supplied on this site will be accurate for every venture and considering the lack of good data for many species NPFL recommends caution in their use.