May 18, 2022
Fiordland sponges turn white as sea warms
Marine biologists have spotted worrying signs sea sponges in Fiordland could be dying off.
Victoria University Te Herenga Waka Professor James Bell says sea sponges fill an important ecological niche, filtering seawater and converting it into food for other animals.
He says the Fiordland sponge populations are showing signs of bleaching – turning white rather than their normal brown – similar to the coral bleaching observed on Australia’s Great Barrier Reef.
He’s blaming a sudden 5 degree rise in water temperature.
“When corals bleach on coral reefs, sometimes they don’t survive. Other times they do regain and they do survive. So we’re not completely sure what will happen next. The fact that they’re still there, they haven’t kind of disintegrated away, gives us some hope they’re not dead yet but because we haven’t had a chance yet to go back and have a really good look we’re not sure,” Professor Bell says.
He says rising global ocean temperatures could have a disastrous effect on New Zealand’s marine and coastal life.