K.J. Friedman, J.D. Bell, G. Tiroba-1998
Aquaculture, 167 (3-4) : 283-299 (Current Contents)
Abstract:
Spatial and temporal variation in abundance of spat of the blacklip pearl oyster, Pinctada margaritifera, was assessed over a 24-month period by deploying spat collectors at 24 sites spanning 500 km of Solomon Islands. Fifty spat collectors were deployed at each site every 3 months and harvested 6 months later. Several different types of spat collector, made of black plastic sheeting or shademesh, were used during the study. Spat were most abundant on shademesh collectors deployed in October and January. At these times, there was an average of 3.0-4.6 spat per collector at the two sites with the greatest abundance of spat. Another 10 sites have average abundances of around 1.0 spat per collector. Sites subject to run-off from high islands yielded the lowest numbers of spat because the collectors placed there became heavily fouled. On the other hand, sites that had clear water, moderate currents, and that were > 35 m from the nearest reef, produced the greatest numbers of spat. However, there was mortality of spat at all sites and 42% of all spat collected were dead at harvest. Much of this mortality was attributed to predation by Cymatium gastropods and crabs that also settled on the collectors. This study showed that there is a potential to collect wild spat for the culture of blacklip pearl oysters from 'open' lagoons of the central-western Pacific, provided the high rates of mortality of spat on collectors can be overcome.
(ICLARM, Coastal Aquaculture Ctr., POB 438, Honiara, Solomon Islands)