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

duration of the dive, maximum bottom depth and the type of substrata found along eachtransect. Position and depth were taken from a Hummingbird 737 combinationGPS/Echo sounder and transect lengths were derived from straight line interpolationsbetween start and finish points. All national staff were trained in all aspects of the surveytechnique and all had an opportunity to experience each role in the team. For many, thiswas their first opportunity to work with GPS and echo sounding equipment as well as thediving methods involved.Divers were not able to access safely depths beyond 35 m. For observations down to 60m a towed underwater camera was used, which recorded onto a Sony DVD recorder.Video surveys were made at four of the sites, where substrate and conditions permitted.Image quality of the camera was less than ideal, but while exact counts of organismswere difficult it was possible to ascertain whether or not dense populations of pearl oysterwere present beyond diving depth.Once the surveys were completed, reporting began. Two training elements wereincluded. Jon Leqata was involved with external consultants in preparation of the reporton the stock assessment and a draft manuscript for submission to the international journalBiological Conservation. Copies of that manuscript are available from WorldFishCenter, Solomon Islands. In addition Dr Hawes from WorldFish Center led a 2-dayworkshop for all staff from the Research and Aquaculture sections of MFMR on dataanalysis, using the survey data as an example.The results of the survey were disappointing. A total of 117 P. maxima were found, butonly 33 of the 96 transects yielded any oysters. The mean (± standard error.) density ofoysters per 400m 2 transect ranged from 1.23 ± 0.38 at Waghina, 1.03 ± 0.27 at Kia and0.66 ± 0.27 at Mboli Passage to