Ecological network metrics in assessing sustainability of the philippine milkfish (Chanos chanos) economic resource system

We used an ecological network analytical approach on a simplified, non-trivial and expandable model of the Philippine brackish-pond milkfish (Chanos chanos) resource network as an initial attempt in quantifying sustainability of aquaculture systems holistically. The approach defines sustainability as robustness which is the appropriation between systemic efficiency and redundancy of network flow structures. The milkfish resource network model analyzed has five categorized functional compartments: fry source, fry distribution channel, production area, product distribution channel and market consumption. The directed flows in-between compartments are taken as economic values of milkfish fry and products from 1979 to 2001 to exclude other production source in the latter years. The results are compared to previous analyzed global economic and local ecological networks as bench marks. The milkfish resource network exhibit high levels of efficiency and sustainability may be improved by managing production flows of the industry that would optimize robustness through increasing redundancy. The approach can be useful in assessing the effects of policy interventions on the systemic sustainability of resource network systems as demonstrated in the case study.