MERGUI, the southernmost district of Lower Burma, in the Tenasserim division, bounded on the W. by the Bay of Bengal and on the E. by Siam. Area 9789 sq. m. Two principal ranges cross the district from north to south, running almost parallel to each other for a considerable distance, with the Tenasserim river winding between them till it turns south and flows through a narrow rocky gorge in the westernmost range to the sea. The whole district, from the water’s edge to the loftiest mountain on the eastern boundary, may be regarded as almost unbroken forest. The timber trees found towards the interior, and on the higher elevations, are of great size and beauty, the most valuable being teak (Tectona grandis), then-gan (Hopea odorata), ka-gnyeng (Dipterocarpus laevis), &c. The coast-line of the district, off which lies an archipelago of two hundred and seven islands, is much broken, and for several miles inland is very little raised above sea-level, and is drained by numerous muddy tidal creeks. Southwards of Mergui town it consists chiefly of low mangrove swamps alternating with small fertile rice plains. After passing the mangrove limits, the ground to the east gradually rises till it becomes mountainous, even to the banks of the rivers, and finally culminates in the grand natural barrier dividing Burma from Siam. The four principal rivers are the Tenasserim, Le-nya, Pakchan and Palauk, the first three being navigable for a considerable distance. Coal is found on the banks of the Tenasserim and its tributaries, but is still unworked. Gold, copper, iron and manganese are also found in various parts of the district, and there are tin mines at Maliwun, upon which European methods have been tried without much profit, owing to the cost of labour.
From the notices of early travellers it appears that Mergui, when under Siamese rule, before it passed to the Burmese, was a rich and densely peopled country. On its occupation by the British in 1824–1825 it was found to be almost depopulated—the result of border warfare and of the cruelties exercised by the Burmese conquerors. At that time the entire inhabitants numbered only 10,000. It had a population of 88,744 in 1901, showing an increase of 20% in the decade and giving a density of 9 inhabitants to the sq. m. Mergui carries on a flourishing trade with Rangoon, Bassein and the Straits Settlements. The chief exports consist of rice, rattans, torches, dried fish, areca-nuts, sesamum seeds, molasses, sea-slugs, edible birds' nests and tin. The staple imports are piece goods, tobacco, cotton, earthenware, tea and sugar. The climate is remarkably healthy, the heat due to its tropical situation being moderated by land and sea breezes. The rainfall is very heavy and usually exceeds 150 inches.
Mergui town has risen into prominence in recent years as the centre of the pearling trade in the neighbouring archipelago. The pearling grounds were practically unknown in 1890, but in the following decade they produced pearls and mother-of-pearl shell of considerable value. In 1901 the population was 11,987; but the census is taken at a time when many of the fishermen and their families are away in the islands. There is a considerable coasting trade with other Burmese ports and with the Straits Settlements.