Intertemporal choice of marine ecosystem exploitation

Exploitation of the marine ecosystem brings with it an intertemporal choice: there is a choice of catching the fish today, or restrain from fishing with the option of an increase in the benefit from future harvest. In a marine ecosystem under common pool management regime the contribution margin from catching the fish belongs to the fisher, while the benefit from the investment of leaving the fish in the sea will be shared in the common pool. The intertemporal choice therefore creates a driver for short sighted use of the ecosystem. The intertemporal balance of the exploitation is analyzed by applying capital theory to a size-based ecosystem model. The model reveals a need for intertemporal balance with respect to both fish size and harvest volume. The management therefore is, at an ecosystem level, to set target and regulate not only harvest volume but also size.