Evidence supporting the need for the effective management of tuna fisheries is abundant¹. Here, we describe a bioeconomic modeling approach designed to identify robust management practices for the Pacific bluefin tuna (Thunnus orientalis, PBT) fishery, while considering the economic effects of implementing such practices.

Our approach is based on a matrix population model (MPM) for the PBT coupled with an inverse demand model of the Tsukiji wholesale tuna market. The MPM is stochastic and seasonally explicit due to multiple sources of uncertainty in fish stock modeling and seasonal patterns in PBT migrations. The aquaculture production is also taken into account via the Douglas-Cobb production function.

The results indicate that the MPM is critically dependent on the parameters (e.g. catchability coefficients) whose values presently cannot be estimated with sufficient certainty. For any management practice to be robust, it must not breakdown under the parameter perturbation. Additionally, capture-based aquaculture in Japan, in which small fish are reared for 2 years, shows potential for the future expansion. These results suggest new ways toward robust management of the PBT fishery in Japan.

¹Juan-Jordá et al. PNAS 108: 20650-20655