Economic feasibility of mussel (Perna perna) and cobia (Rachycentron canadum) produced in a multi-trophic system

Integrated multi-trophic aquaculture has been considered as an alternative for the sustainable development of mariculture. This study evaluated the use of a multi-trophic system in mariculture in order to improve economic viability indices and reduce environmental impacts, leading to a sustainable production. To do so, the economic indicators of two monotrophic crops were considered: Perna perna mussels and Rachycentron canadum cobias, along with a multi-trophic system involving both species. The indices for the evaluation of profitability were the internal rate of return (IRR), the payback period (PP) and the net present value (NPV). Investment analyses were realized through cash flow and determination of economic viability indicators for a period of 10 years. The systems were evaluated in different scenarios. Each scenario was estimated by means of 20% and 40% variations of the values adopted for the following parameters: unit price of cobia juveniles, average price of the feed, cobia commercial price, mussel commercial price, cobia productivity, and mussel productivity. The multi-trophic system showed greater economic viability in the different scenarios evaluated. This system demonstrated greater resilience, which is more economically attractive to an entrepreneur. Production diversification is an alternative option with a lower associated investment, which can favor economic return and mitigate the risks of small-scale systems dedicated to monocultures.