Bakau Bast (Dutch: bakau-bast) was an indigenous export product (Dutch: inheems exportproduct) of the colonial residency of Atjeh, consisting of the bark (Dutch: bast) of the Rhizophora mangrove trees (Dutch: bakau-bomen) that fringed the estuaries and tidal swamps of the Atjehnese coast. The bast was harvested, dried, and exported for its high tannic acid (Dutch: looizuur) content, used in European tanneries for leather production and in the textile industry for dyeing. Although never as lucrative as pinangnut or rubber, bakau bast provided a steady supplemental income for coastal Acehnese communities engaged in mangrove exploitation during the late nineteenth and early twentieth centuries.
The mangrove resource
The mangrove forests of Atjeh — particularly along the East Coast of Sumatra, the Tamiang river delta, and the estuaries of the Atjeh River — were among the most extensive in the Indies. The dominant species, Rhizophora mucronata and Rhizophora apiculata, were known to colonial foresters as bakau and were valued for the high proportion of tannin in their bark. Mangrove bark typically yielded between 25 and 35 per cent tannic acid (Dutch: looizuur) by dry weight, a concentration that rivalled the best European and South American tanning materials.
Colonial forest law classified the mangrove belt as state forest (Dutch: staatsbosch), and the Buitengewesten forestry service regulated felling through concession licenses (Dutch: kapvergunningen) issued to Acehnese, Chinese and European concessionaires. Cutting was concentrated in the drier months when the swamp could be entered on foot or by small perahu.
Extraction and processing
The bark was stripped from felled trees in long ribbons using a specialized bark-iron (Dutch: bastmes), then bundled and dried in the sun for several weeks. Once dried, the bast was either shipped raw to European tanneries or processed locally into a concentrated tannin extract. In the simplest domestic process, the bark was boiled in large copper vats (Dutch: ketels) and the resulting tannin liquor evaporated into a thick dark paste used locally for dyeing cotton and preserving fishing nets. For export, the dried bast was pressed into bales of approximately 80 kilograms and shipped through Belawan and Kuta Raja to Amsterdam, Hamburg and Liverpool.
A secondary use of the bakau-bast trade was the production of cutch (Dutch: catechu), a dark resinous extract used in dyeing sails and fishing gear. The combination of bark, cutch and mangrove timber gave the Acehnese mangrove economy a layered structure that survived the decline of the individual commodity streams.
Economic significance
Bakau bast never rivalled the great plantation crops of rubber, copra or palm oil, but it filled an important niche in the coastal economy. It provided cash income to fishing villages in the off-season, employed small perahu owners as transporters, and fed the European leather industry that supplied shoes and harness to the Netherlands Indies Army and to civilian markets in Java and Europe. The trade also intersected with the colonial fisheries and salt regimes, since tanned fishing nets lasted longer in salt water than untreated ones.
After 1920 the expansion of synthetic tanning agents and the substitution of chrome tanning for vegetable tanning reduced European demand for mangrove bark. By the 1930s bakau bast exports from Atjeh had fallen to a fraction of their pre-war peak, although the mangrove forests themselves remained important for firewood, charcoal and coastal protection. The commodity is a reminder of the diversity of the Atjeh export economy before its consolidation around rubber and oil palm.
See Also
- Resin (Aceh)
- Rattan (Aceh)
- Kapok Fiber
- Copra
- Buitengewesten
- Oostkust van Sumatra
- Belawan
- Koeta-Radja
- Dutch East Indies
- 1900
- 1920
- 1930
Source
DLP-84-Atjeh.pdf, pp. 12-13.