A marine heatwave in Fiordland is thought to be responsible for the bleaching of millions of sea sponges.
It was first discovered in May last year, but Marine biologist Professor at Victoria University of Wellington, James Bell led a return trip to Fiordland this summer to investigate what had happened to the sponges.
James Bell talks to Jesse about what they've found.
Photo: Dr Valerio Micaroni and Francesca Strano / Victoria University of Wellington
