This article is the summary of Chapter 8, The Bio Economic Seaweed Model (BESeM) for Modeling Kappaphycus Cultivation in Indonesia, from an e-book entitled Tropical Phyconomy Coalition Development: Focus on Eucheumatoid Seaweeds, written by various authors. While the discussion centers on Kappaphycus alvarezii, a similar study could also apply to Eucheuma spinosum and Gracilaria.
Using the Bioeconomic Seaweed Model (BESeM), which consists of a biological module and an economic module, this article answers two questions. First, is a farmer better off with 12 cycles of 30 days, 8 cycles of 45 days, or 6 cycles of 60 days? While yield per harvest will normally be higher with a longer cycle, aggregate yield (over a year) might be higher with more, yet shorter cycles. Second, how should we allocate the harvests between those for sale and those for replanting? Is selling 90% and replanting 10% of the harvest the right management decision?
We estimate the gross farmer income to be IDR 5.8 million per head per month. This is about 2x the minimum wage in South West Sulawesi (IDR 3.2 million). Based on the study the authors have done, 45 days is the right harvest cycle length; one farmer should have 300 lines @ 25 m length. Assuming the market can absorb all supply, increase the fraction replanted to 25% to increase income 2.5x.
