When deep-sea researchers sent their underwater robot more than one mile deep in waters off Hawaiʻi, they were surprised to encounter a record-breaking creature that might be thousands of years old.
During a 2015 expedition in the Pacific Ocean, they found an enormous glass sponge, which turned out to be a record breaker: the biggest sea sponge on the planet.
What is the biggest sponge in the world?
The biggest sea sponge currently on record was discovered in the deep sea off Hawaii in August 2015.
Marine scientists from NOAA's Office of Ocean Exploration and Research were exploring the seabed when they happened upon the mega sponge. Although they didn’t take samples of this particular colony, they collected samples of another sponge nearby, which they believed was the same species. Analysis showed that it was a type of glass sponge belonging to the family Rossellidae and subfamily Lanuginellinae.
Before this discovery, the world’s largest sponge was believed to be a cloud sponge (Aphrocallistes vastus) in shallow waters (less than 25 metres) off the coast of Canada. This measured 3.4 metres long 1.1 metres high and 0.5 metres wide.
The researchers took measurements of the newly discovered sponge and confirmed that the mammoth find was bigger than its Canadian counterpart. It was officially a world record-breaker.
Where was it found?
Marine researchers were on an expedition in Papahānaumokuākea Marine National Monument off the Hawaiian Islandsin the Pacific Ocean when they came across a gigantic sponge 2,117 metres deep.
Although deep-sea researchers often see spectacular sights, this was clearly something special. “Oh my goodness! Where did this guy come from?” exclaimed one of the researchers on first seeing the epic organism. “Holy guacamole here – look at this thing!”
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How did they measure it?
Whipping out a tape measure isn’t exactly a simple task when you’re using a remotely operated vehicle (ROV) to explore the deep sea. So, experts use lasers to figure out the size of the creatures they see in the deep.
To measure its height and width, they projected two parallel laser beams onto the sponge and took pictures. Because they know how far apart their two lasers are set, they can use the markings as a reference to measure the entire object. To determine its length, they took a photo from above and compared the dimensions with those of the ROV.
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What does it look like?
In a word: huge. Measuring 3.5 metres long by 2 metres high and 1.5 metres wide, this vast sea sponge is the size of a car.
As the video pans across the colossal animal, one of the scientists wonders whether the sponge is even bigger than the remotely operated vehicle (ROV) they’re using to explore the seabed.
Bursting out of the rocky seabed, the creamy-white sponge looks like an awkward pile of laundry – the pleats of its body give it a larger surface area for filtering water, which is how it takes in food.
What does it eat?
Sponges are filter-feeding animals that eat tiny particles in the water, such as bacteria, detritus and plankton. They draw water in through special pores on their bodies (called ostia) and capture the debris that passes through before the ejecting the water through an opening called the osculum.
This allows them to take in nutrients but it also purifies the water that is pumped through. Sea sponges can filter huge amounts of water: some can take in 20,000 times their volume in just 24 hours.
How old is it?
It’s difficult to know exactly how long this creature has been growing on the seafloor but sea sponges can have very long lifespans.
When the scientists published their discovery of the world’s biggest sponge in the journal Marine Biodiversity, they wrote: “While not much is known about the lifespan of sponges, some massive species found in shallow waters (<30 m) are estimated to live for more than 2300 years.”
This vast creature may well have been on this planet for thousands of years.
Is it under threat?
It might be. Some sea sponges are fragile and can be easily damaged. As filter-feeders, these animals are impacted by poor water quality so chemical and microplastic pollution can be harmful to them. And, as they can’t move or swim away like a fish or marine mammal, if there’s a problem in the region, they have no way of escaping it.
“The finding of such an enormous and presumably old sponge inside the Papahānaumokuākea Marine National Monument underscores the need to protect this area using the highest conservation measures available,” write the study authors.
Papahānaumokuākea was declared a marine sanctuary in 2025. The protected area measures 582,570 square miles.
