The Bonamia species that occurs in New Zealand is not B. ostreae . It has been named Bonamia exitiosus. B. ostreae has never been reported in New Zealand. Bonamia exitiosus occurs in commercial beds in Foveaux Strait, where it has a high prevalence and is associated with raised mortality in mid to late summer. It occurs intermittently around the South Island and in Wellington Harbour (North Island).