Multi species model (anchovy, yellowstripe scad and narrow-barred Spanish mackerel) in Semarang coastal

Abstract

The fishery sector in Semarang has been mostly dominated by artisanal fisheries with multigears and multi-species. Although the fishery sector was not the major contributor to the GRDP of Semarang city, the population of fishermen reached 1,068 whose welfare should be concerned. The fishery sector helped the eradication of poverty and supported food security in Semarang city. Anchovy (Stolephorus sp.), yellowstripe scad (Selaroides leptolepis) and narrow-barred Spanish mackerel (Scomberomorus commerson) share an ecological relationship as predator and prey, which both have been major marine commodities in Semarang city. Proper management should be applied to these species in an integrated manner. This study developed and applied a multi-species (predator-prey) model for anchovies, yellowstripe scad and narrow-barred Spanish mackerel. In this study, the production and fishing activities were developed particularly for the three types of fish. The results indicated an interrelated relationship between anchovy, yellowstripe scad and narrow-barred Spanish mackerel productions. Optimal anchovy production (237,230 kg) was obtained when the fishing activities involved 779 fishermen. Whereas, the optimal yellowstripe scad production (6,873 kg) was obtained when 791 fishermen were involved, and the narrow-barred Spanish mackerel production was at the highest (159 kg) when 1,168 fishermen were involved.