Benthic Impact Study, Cultured Pearls

The premium pearl in the world, South Sea Pearls are cultured along the remote tropical Kimberley coastline of Western Australia. The Pearl Producer’s of Australia (PPA) pride themselves on their low impact culture techniques, but find themselves under increasing pressure to prove their credentials with independent scientific studies.

Dr Prince worked with the PPA to initiate, commission, supervise and facilitate a study by independent researchers from the University of Newcastle, into the potential for benthic impacts under pearl leases of long standing. Several of the oldest (50 years+) most intensively used leases were selected and benthic sediments and fauna benthos compared over several years between these sites between them and nearby control sites.

In addition to identifying many new species the study found the Kimberely sediments are incredibly diverse and seasonal cycling is dynamic. Despite being possibly the most exhaustive study of its type published, the study could find no impact that could be attributed to the heavily used lease areas. Undoubtedly due to the low stock densities compared the extreme tidal fluxing of nutrient and sediments through the leases. On this basis the PPA recommended against members undertaking the expense and risk of benthic monitoring within each farm’s Environmental Management System, but recommending repeating this type of targeted study periodically, or if culture techniques change.