Artisanal gold miners have damaged large swathes of farmland over the past year, worsening the outlook for the cocoa harvest in the world’s second-largest grower.

More than 19,000 hectares, or about two per cent of cocoa plantations, have been destroyed by so-called galamsey, small-scale miners who often operate illegally, Fiifi Boafo, spokesman for the Ghana Cocoa Board, said by phone.

Authorities had already warned that Ghana is unlikely to meet its initial output target of 850,000 tons this year. 

"This will definitely have an effect on the crop outlook,” said Boafo who declined to give an output forecast. 

Cocoa is the third-biggest foreign-exchange earner for Ghana after gold and oil. Small-scale mining is rife in Africa’s biggest gold producer, accounting for a third of output. While mining activities, which contaminate waterways with metals and chemicals, have affected farming for decades, the practice is intensifying, Boafo said, with some gold mining licenses encroaching on farms. 

Meanwhile, the current crop has suffered from long spells of drought and the after-effects of a severe outbreak of swollen-shoot disease. Cocoa output slumped 34% in the first six months of the season, compared with the same period last year, people familiar with the matter told Bloomberg last month. This follows last season’s record harvest of 1.05 million tons. 

Losing even “an inch of land suitable for cocoa production has an impact on our business,” Samuel Adimado, president of the Licensed Cocoa Buyers Association of Ghana, said in an emailed response to questions. Government measures to curb galamsey activities “should be reviewed,” he said.

The cocoa regulator is engaging with the Minerals Commission to use location data to identify mining on farms, Boafo said. It also plans to ensure mining companies compensate cocoa farmers impacted by their activities.