New Zealand scientists discovered thousands of bleached sea sponges in May of this year, in cold waters off the country's southwestern coast. Further findings showed that the damage was far worse, with millions of millions of sea sponges affected throughout the Fiordland region.
This is one of the most abundant sponges in Fiordland, and so it's a really large-scale event, said James Bell, a marine biology professor from New Zealand's Victoria University.
Bell, who led the team responsible for spotting the initial bleaching event last month, told CNN that some sponges were still alive and consuming oxygen despite the extensive mass bleaching.
This region was so abundant and rich in marine life, and it was almost like a white graveyard when we discovered it, it was really devastating and traumatic, he said. We can conduct experiments on board our boat to try and understand how the sponges were affected by warmer temperatures. Many of them were already very unhealthy and stressed. New Zealand is seeing its worst mass bleaching of important sea sponges. Sea sponges come in a variety of sizes, colors and textures and provide food and water for other marine animals like crabs, algae and fish. They pump out large volumes of water and capture tiny particles, bacteria, plankton and algae, and also recycle carbon on the sea floor, Bell said. They also provide shelter for marine creatures and increase habitat areas of the sea floor. They are very underappreciated. Last year was the hottest on record for the world's oceans for the third year in a row, placing additional stress on the marine ecosystems. Australia's Great Barrier Reef suffered its sixth mass-bleaching event this year. Coral bleaching was also confirmed by studies at multiple reef sites. The Great Barrier Reef is now believed to have lost half of its coral population to climate change in the past three decades, according to studies. Coral sponges, like coral, are heavily affected by extreme ocean temperatures and turn white as a stress response to temperatures that are too warm. The sea creatures play an important role in marine ecosystems and scientists say their loss could affect millions of other marine animals. Warming ocean temperatures are also affecting sea sponge populations in other parts of New Zealand, according to Bell. Swathes of dead sea sponges were discovered in the country's northern coastal areas. During a long marine heatwave, some were found to be melting. He said that the mass bleaching event highlights how dramatically oceans are changing due to global warming and climate change. It should serve as a wake-up call. We need to take action now, not in 10 or 15 years because by then it would be too late and we'd have lost all ecosystems and species.