Ann: Perseus Updates Mineral Resources and Ore Reserves, page-7

As uniqque2008 pointed out, a lot of this is simply due to depletion of Reserves from normal mining operations. I'm not sure what you expected to see, but it should not be alarming. You only report in-situ Resources i.e. what you have not mined.

At Edikan, Measured Resources (which are essentially Reserves in every sense) have reduced considerably, but Indicated Resources increased almost by the same amount. These Indicacted Resources can be drill tested further, and a portion of them will be upgraded to Measured, and ultimately convert to Reserves. In turn, some Inferred Resources will convert to Indicated with further drilling.

Another way to replace Reserves is by an increasing gold price environment, by which previously lower grade and uneconomic material suddenly becomes economic to mine.