Top publication by Yuanming Ni and Leif K. Sandal

27 November 2018 15:27

Top publication by Yuanming Ni and Leif K. Sandal

The article "Seasonality matters: a multi-season, multi-state dynamic optimization in fisheries" has been published in European Journal of Operational Research.

European Journal of Operational Research is on level 4 in the ABS Academic Journal Guide.

Ni, Yuanming, and Leif K. Sandal: Seasonality matters: a multi-season, multi-state dynamic optimization in fisheries, European Journal of Operational Research, Online 23.11.2018.

Abstract

Many biological and economic processes in fisheries occur seasonally though most of the extant literature tends to neglect periodicity. This work is an attempt to treat seasonality in a systematic way. We present a multi-season multi-state bioeconomic model and apply a periodic Bellman approach using dynamic programming to obtain the optimal feedback policy of each season. Our approach has rich potentials. It could deal with seasonal patterns of arbitrary uneven lengths: some may span years and some may occur within a year.

Our numerical illustration demonstrates that a seasonal dynamic optimization model allows for naturally occurring seasonal moratorium or potentially a Marine Protected Area (MPA). It shows that there exists optimal dynamic paths that develop into a permanent equilibrium cycle, which consists of one harvesting season followed by a moratorium period. This indicates an optimal closure of the fishery that a yearly model would overlook. Fishing pressure on the mature stock elicits even heavier harvesting in the next season on the same group. A protective moratorium of the immature hinders the value of the whole stock.