Riverine floodplains around the world are economically important environments, as they contain abundant fisheries that have been exploited by humans since prehistoric times. In low-lying and topographically flat southeast Sumatra, the river basins of the Musi and Batang Hari rivers have some of the most extensive floodplains of Indonesia. Based on flood hazard maps with a ten year return period, there are over 6000 km2   and 2000 km2 of freshwater floodplain above the cities of Palembang and Jambi, respectively. At a study site, where c. 12 km2 is inundated during the height of the flood, the average yearly catch between 1984–1992 was c. 50 tonnes, and in its regency (an administrative division under province) c. 16,000 tonnes of fish were caught in the 1990’s. While these numbers are naturally not directly transferable to the past, they do provide us with an idea of the productive potential of floodplain fishing in the area. Historically floodplain fishing is traceable in South Sumatra to at least to 1630 CE, when fishing rights to parts of the floodplain were sold at an auction, a practice that continues to this day. As palimpsests of earlier traditions, the fishing methods and gear used there today – portable traps, hooks, seines, and barriers – would be familiar to prehistoric fisher folk. In this presentation, by considering biocultural heritage as a starting point, I will propose a longue durée hypothesis for the use of southeast Sumatran floodplains for fishing, extending back to the Srivijayan period and beyond. I will also examine the likely socio-economic impact of fishing in the past, and suggest means on how material evidence might be found to support the hypothesis.