Stimulating investment in pearl farming in ... - World Fish Center

Abundance, Size Structure and Quality of Silver-lip Pearl Oysters in the Solomon Islands Final, June 2008decade prior to this, the annual exports of black-lip and silver-lip pearl shell varied between15 and 44 tonnes and between 6 and 25 tonnes, respectively (Richard et al. 1994). The exportstatistics provided to the Solomons Islands Fisheries Division by MOP traders in Honiaraindicate that most of the pearl shell exported came from the Waghina area (Colgan 1993).1.2.2 Pearl Oyster CultivationThere have also been several attempts to establish a pearl culture industry. The Palmerfamily, assisted by Stan Hynd, a CSIRO scientist, cultured pearls between 1968 and 1972, butceased production due to problems with spat collection and breeding techniques (SPC 2002).In 1994, the International Centre for Living Aquatic Resource Management (ICLARM nowthe WorldFish Center) and the Fisheries Division of the Solomon Islands Government (nowthe Ministry for Fisheries and Marine Resources) commenced a large-scale black-lippedpearl oyster spat collection programme with a view to investigating pearl culture. The studyinvolved the assessment of spatial and temporal variation in abundance of spat settling onartificial collectors deployed at 24 sites spanning 500 km of ‘open’ reef systems in theSolomon Islands (Friedman et al. 1998). This study showed that wild black-lip oyster spatcollected in ‘open’ reef systems could form the basis of a culture industry, provided thatpredation can be controlled. The growth and survival of juveniles has also been assessed inlantern nets suspended from longlines at depths of 3-4 m at nine shallow water sitesthroughout the Solomon Islands and at depths of 9-12 m and 35-45 m within an area of theGizo Lagoon (Friedman and Southgate 1999).In 1996/1997, the WorldFish Center in collaboration with the Australian Centre forInternational Agricultural Research and the Solomon Islands’ government initiated aprogram to culture high-quality black pearls in a sustainable manner in the Solomon Islands.A pilot farm was established near Gizo in the Western Province of the islands. The first cropof cultured pearls from the farm was auctioned for more than US$29,000 in September 2000and the second crop auctioned in June 2004 raised over US$18,000 (WorldFish Center 2007).A report has recently been produced on past research and development on black-lip pearloysters in Solomon Islands (Hawes and Messia 2007).1.2.3 Previous Surveys of Pearl Oyster StocksIn 1988, potential silver-lip pearl oyster resources in the Santa Isabel region were surveyedby three divers employed by Solomon Taiyo Ltd. A total of 49 silver-lip oysters were foundover the two week survey with the majority coming from Kia and Port Praslin Passage.Most of these oysters were considered unsuitable for farming, because they were larger than200 mm DVM (Nichols 1988 in Colgan 1993). In 1990, a six-day long survey conducted offKia by two divers yielded 46 silver-lip oysters, most of which were again too large for pearlculture (Batty and Kile in Colgan 1993). In December 1990, a week-long survey of pearloyster grounds at three depths targeted by commercial divers was carried out primarily inthe Waghina area, but with two additional dives at Kia (Colgan 1993). The substratum andconspicuous benthic organisms found at each site were also noted. Only two oysters werefound in the Waghina area at depths of 34-36 m and 28-31 m respectively, whereas tenindividuals were found at Kia at depths between 39 m and 51m. These stock levelsindicated that, at the time, there was no potential for commercial fishing or pearl culture inthe Waghina area. Suitable habitat for silver-lip pearl oysters in the form of “gardenbottom” characterised by sponges, soft corals and whip corals was fairly common, beingrecorded at approximately half the sites sampled at Waghina.The Ecology Lab Pty Ltd – Marine and Freshwater Studies Page 3