In the nineteenth century, prior to the development of the cultured pearl industry in Japan, mother of pearl shells and pearls were some of the most valuable marine animal products of the time, and the demand for these products had been increasing rapidly in Europe and North America. In Southeast Asia, there was a thriving pearl shell and pearl industry in the early 1800s, based in the islands surrounding the Sulu and Celebes Seas which sold or bartered its products to China. So great was this trade that providing sufficient labour was a problem and therefore slave raiders were employed to capture slaves in the islands and coastal villages of the Malay Peninsula and bring them to Manila and Jolo. At the height of the trade in the 1830s, as many as 68 000 people were employed in diving for pearl shell in the area, more than the number of fishers in the whole of Java and Madura. About 730 tonnes of pearl shell was exported from Jolo each year. The pearl shell and pearls that were not exported directly to China (either by Chinese traders or by British East India Company vessels) were sent to the market at Makassar for sale.
The pearling areas around the Sulu and Celebes Seas, the majority of which is now encompassed within the Philippines, is still by far the major producer of pearl shell and pearls (as opposed to pearls from the pearl culture industry) in the region with pearl shell production in 2002 being about 25000 tonnes or over 99 percent of total production in the region (FAO, 2004). This production is, however, about the same level as the 1960s although landings have fluctuated considerably during that time.
The early, rapid development of the pearl shell and pearl industry in the eastern islands area (which almost exclusively used Japanese and Filipino divers) quickly resulted in the more easily accessible stocks coming under pressure and, as pearl stocks in shallower waters were intensively harvested, it became necessary to find ways to harvest in deeper waters to maintain and increase supplies. In 1839 Augustus Siebe developed diving gear which was eagerly adapted by companies with sufficient capital to purchase the necessary equipment. The addition of diving equipment not only enabled divers to reach greater depths (up to approximately 54 m) than had previously been possible with free-diving, but also to increase the proportion of the year in which it was possible to collect oysters from three to nine months. The development also enabled stocks in deeper waters to be exploited and, by the late 1800s, areas in the Aru Islands, the Mergui Archipelago and the Sulu Archipelago were being fished. Faced with the high costs of the pearling operations, pearlers generally adopted the strategy of extracting as much as possible as quickly as possible and then moving on to another oyster bed. This strategy was adopted in all three of the main pearling areas.
The first area where diving equipment resulted in an increase in yields was in the Mergui Archipelago where, according to an official report by Rudmose Brown and Simpson in 1907, there was “no systematic pearling in the archipelago before 1891 when the attention of the Government was drawn to these banks by a Queensland pearler [presumably from the Torres Straits].” To manage this fishery, the Government of Burma immediately introduced a “block system” whereby the government auctioned the rights to collect pearl oysters in five “blocks” covering the richest pearling grounds. As a result of this system the mentality was adopted that it was imperative to extract as much pearl shell as possible during the year as the same company would not necessarily secure the same block the following year. Official figures indicate that yields rose dramatically from 26 tonnes in 1891/92 to 340 tonnes in 1894/95, leading to the emergence of Mergui as a boomtown. By 1900/01 the yield had fallen to 66 tonnes, and the government abolished the block system and replaced it by a system under which pearlers bought a licence for each pump they used. There was apparently no limit on the number of licences used.
During this period the accepted view was that there was little danger of overexploitation of the Mergui pearl beds as the beds were continually restocked by the offspring produced by oysters in deeper waters beyond the reach of the divers. It was argued that there was a “natural balance” between the number of divers and the quantity of shell available for, as yields fell, divers would leave and the stocks would recover. As a result it was concluded there was no need for any sort of regulation of the Mergui pearl fishery.
Pearling also expanded into the Aru Islands where Australian pearlers, using Japanese and Filipino divers, adopted diving gear in the 1870s. The richest grounds were those along the eastern side of the Islands which, after a few failed attempts at development, were developed by the Australian pearlers from Torres Strait in 1905, under a three-year concession granted by the Netherlands Indies Government. These grounds had hardly been touched by divers and, initially, catches were about twice what they were in the Torres Straits. In addition, the operations were significantly more profitable because licence costs, labour and the cost of living were cheaper than in the Torres Straits fishery.
This Aru Island fishery quickly expanded and by 1906 there were 150 vessels working in the area, operating as a fleet with multiple diving vessels supplying a schooner which acted as a “floating station” where sorting, cleaning and packing was undertaken. In 1906, indigenous divers in the area (who, under the terms of the concession, had exclusive access to pearl shell in waters less than 5 fathoms) supplied only 13 percent of the total 950 tonnes that were taken in the area. The company operating the fleet was the world’s largest producer of pearl shell and, in the same year, supplied 37 percent of mother-of-pearl shell imported into London.
However, within a few years, yields began to decline as the three year concession provided no long-term incentives for preservation of the stock and contemporary anecdotal evidence appears to indicate a reduction in catch rates per vessel of about 50 percent between 1905 and 1908. Although the concession was actually renewed several times, the company operating the fleet had withdrawn most or all of its vessels by 1916. However, this withdrawal did not end pearling activities in the Islands with the indigenous, shallow water fishery continuing and a few diving vessels operating well into the 1930s. These activities continue today from smaller, motorized vessels.
In the Sulu Archipelago, the introduction of diving technology came later and in a milder form than in other areas and, in 1914, there were 73 pearling vessels operating there, 40 of which were owned by a Japanese company and the rest by individuals of various ethnicities. Only two of the Japanese vessels had motor-driven pumps for diving. By 1930, there were only 24 vessels operating, five of which were equipped with engines and moto-driven air pumps. The Sulu Archipelago area appears to have exported about 300 tonnes of pearl shell in 1914 and, throughout its development, was distinguished by a greater reliance on indigenous fishers operating in shallow water for most of its production. Yields do not appear to have declined as precipitously as other areas where mechanized diving operations were more important, and Butcher (2004) suggests that this may have been a result of the more extensive nature of the pearl beds and the apparently less intense exploitation.
The introduction of mechanical diving technology in the late nineteenth century therefore led to a boom-and-bust development of the pearl shell beds of the region with pearl beds being sequentially depleted. Throughout this period of development, however, it is interesting to note that little concern was expressed for the long-term sustainability of the stocks since it was commonly believed that depleted adult stocks would be quickly replenished from untouched “deeper water” stocks. The decline in abundance of pearl shell helped drive an increasing demand for trochus shell and other gastropods as a substitute for pearl shell which was used in the manufacture of buttons. But, after the Second World War, it was the development of cheap plastic substitutes for button manufacture that resulted in the decline of the industry although it continues today as a small, artisanal fishery in the Philippines.
