New Zealand: Sea sponge populations ‘dying out by the millions’ due to climate change

New Zealand scientists discovered thousands of bleached sea sponges in May this year in frigid waters off the country’s southwest coast. Further results showed that the damage was much greater, with millions, and possibly tens of millions, of marine sponges affected throughout the Fiordland region.

“It’s one of the most common sponges in Fiordland, so it’s really a big deal,” said James Bell, professor of marine biology at the University of Victoria in New Zealand.

Bell, who led the team responsible for finding the initial discoloration last month, told CNN that despite extensive mass discoloration, some sponges are still alive and consuming oxygen.

“This region was so abundant and rich in marine life, and when we discovered it, it was almost like a white graveyard, it was really devastating and traumatic,” he said. “We can do experiments aboard our boat to try to understand how high temperatures have affected the sponges. Unfortunately, many of them were already very unhealthy and stressed.”

New Zealand is experiencing the largest mass bleaching of important marine sponges.
Sea sponges come in a variety of sizes, colors and textures and play a critical role in marine ecosystems, providing food and shelter for other marine animals such as crabs, algae and fish.

“They pump out large volumes of water and trap the smallest particles, bacteria, plankton and algae, and recycle the carbon on the seafloor,” Bell said. “They also provide shelter for sea creatures and increase the habitat on the seabed. They are very underestimated.”

Oceans are warming at record speed

Last year was the hottest year in the world’s oceans for the third year in a row, putting enormous additional stress on marine ecosystems.

The Great Barrier Reef in Australia experienced its sixth mass bleaching event this year. Research has also confirmed coral bleaching on several reef sites.
The Great Barrier Reef has experienced its sixth mass bleaching event, affecting 91% of surveyed reefs.
The Great Barrier Reef is currently considered lost more than half coral populations to climate change over the past three decades, according to research.
Sea sponges like coral, also suffer greatly from extreme ocean temperatures and turn white in response to stress at too high temperatures.

Sea creatures play an important role in marine ecosystems, and scientists say their extinction could affect millions of other marine animals.

Bell noted that rising ocean temperatures are affecting sea sponge populations in other parts of New Zealand as well. stripes dead sea sponges were found in the northern coastal regions of the country. Some of them have been found to “melt” against the backdrop of a sustained sea heat wave.

“The massive bleaching highlights once again how much the oceans are changing due to global warming and climate change,” he said. “This should serve as a wake-up call. We need action to combat climate change now, not in 10 or 15 years, because by then it will be too late and we will have lost all ecosystems and species.”