Bio-economic model of Danish seine and purse seine fisheries in Rembang Regency, Indonesia

Abstract

The fisheries in Indonesia is multi-gears fisheries, including in Rembang Regency. Rembang Regency had fishery production of 36,243 tons in 2017 and very dependent on purse seine and Danish seine fisheries. Although they have different fishing operation, but types of fish caught by purse seine and Danish seine are partly of the same species. The interrelation of fish species caught shows the risk of interrelation between purse seine and Danish seine (negative externalities) which can encourage overfishing. The purpose of this research was to make the model of relationship between Danish seine and purse seine fisheries in Rembang Regency with a bio-economic approach. We have modified Gordon-Schaefer model (single gear) to be a multi-gears model that can explain the reciprocal relationship between Danish seine and purse seine fisheries, and also we did optimization of production and profit. This research has proven that Danish seine fishing efforts have a negative impact on the production of purse seine fisheries, and vice versa. The combination of 328 units of purse seine and 304 units of Danish seine will produce optimal aggregate production (62,286 tons per year). While the combination of 176 units of Danish seine and 348 units of purse seine will generate an aggregate profit of IDR 510 billion per year as the win–win solution for both Danish seine and purse seine fisheries. The highest aggregate profit will occur at 370 units of purse seine fisheries and 0 units of Danish seine, which will generate a profit of IDR 535 billion per year.