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

30Spat collector -125201510a. NoroLive spatTotal spat501997 1998 1999 2000 2001 2002 2003 2004 2005 200630Year25b. GizoSpat collector -1201510Live spatTotal spat501997 1998 1999 2000 2001 2002 2003 2004 2005 2006YearFigure 8. Mean abundance of spat (total and live) on collectors at a) Noro and b) Gizoin the Western Province of Solomon Islands. Error bars are 95% confidence limitsaround live spat.4.5 The effects of immersion time on spat collectionsWhile it might appear logical to expect that the number of spat collected and the sizeof those spat will increase with duration of immersion – as more spat recruit andrecruits grow – this has proven not to be the case (Figure 9). Data in figure 9 wereobtained by sequential harvesting of spat collectors deployed in December 1995 after3, 4, 5 and 6 months (Friedman and Bell, 2000). The decline of numbers from threemonths onwards indicates a net loss of spat from the collectors i.e. losses exceededrecruitment. In a repeat of this experiment one year later, the authors found a similarresponse, though the number of spat peaked at four rather than three months,suggesting a longer or delayed recruitment relative to the first experiment.11