Norfolk Island’s unique corals under triple threat from disease, El Niño and now government-approved dredging

Norfolk Island has corals found nowhere else which could be rapidly lost ‘and we won’t get them back,’ Prof Bill Leggat says. Photograph: Tom Bridge

Scientists fear unique corals that fringe Australia’s remote Norfolk Island could disappear because of a triple threat of disease, El Niño and a federal government plan to dredge a neighbouring shipping channel.

A failure to manage sediment and pollution washing into bays from cattle farming, cleared land along with wastewater has been blamed for widespread disease and outbreaks of algae over the corals.