Scientists find nine new sponge species in glimpse of Alaska’s deep-sea diversity
But their habitat is threatened by bottom trawling in the region and Trump’s plan to expand seafloor mining
Scientists have discovered nine new deep-sea sponge species off Alaska, offering new insights into the region’s largely unexplored marine biodiversity.
The National Oceanic and Atmospheric Administration (Noaa) announced the discovery on Thursday, saying the species were found in the Gulf of Alaska and the Aleutian Islands. The findings bring the total number of known sponge species in Alaska to 232.
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The specimens were collected during Noaa Fisheries’ annual bottom-trawl surveys, which monitor groundfish and shellfish stocks. Researchers analyzed samples collected as far back as 2012, describing the new species in two recent scientific papers.
Often described as living water pumps, sponges are among Earth’s earliest multicellular animals, dating back more than 600m years. They filter seawater and help create habitats on the seafloor, despite having no brain or complex organs.
“Sponges are ecologically important,” said Sean Rooney, a Noaa fisheries biologist and co-author of the studies at the agency’s Alaska Fisheries Science Center. “They aren’t plants, but like trees in a forest, they provide complex structure along the seafloor that creates habitat and refuge for commercially important fish and crabs,” he added.
“Each time we find a new species, it opens up new doors … Deep water is hard to access, especially rocky places we can’t reach with bottom-trawl surveys. There are now more than 232 identified species of sponges in Alaska, and probably hundreds more that we don’t know about yet. The future in this field is exciting,” he continued.
Unlike most marine animals, which can be identified by visible traits such as fins and body shapes, sponges can be much harder to distinguish. Because they lack complex organs and other distinctive external features, scientists often rely on their microscopic skeletons and genetic material to identify them.
“DNA barcodes provide a quick genetic reference,” said Meredith Everett, a biologist at Noaa’s Northwest Fisheries Science Center. “Sponge DNA can be tricky because they filter-feed, and within their tissues we may find foreign DNA and biochemicals that inhibit testing. But despite the challenges, we successfully developed several new barcodes for Alaskan species,” she added.
Dense sponge communities are considered essential fish habitat by Noaa because they provide shelter that supports fish survival, growth and population recovery.
Sponges also produce chemicals to defend themselves against predators and competing organisms. Some of these compounds have shown promise for potential use in cancer treatments.
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Yet despite their ecological importance, Alaska’s deep-sea sponge communities face growing threats from Donald Trump’s proposals to expand deep-sea mining for critical minerals such as nickel and copper – used in military and technological applications – as well as bottom trawling in the region.
Environmental groups have opposed the proposals, warning that the activities could damage fragile seafloor ecosystems as the climate crisis intensifies.
Cooper Freeman, Alaska director of the Center for Biological Diversity, said: “Alaska’s sponge gardens do so much for a healthy ocean, including providing shelter and serving as vitally important nurseries for all kinds of fish and crabs. Bottom trawl fishing is so damaging and unsustainable because it indiscriminately destroys the habitats that support future generations. Adding seafloor mining to the picture adds insult to injury, scraping up and devastating life on the bottom of the ocean.
“Instead of stewarding Alaska’s precious sponge gardens so they can support Alaskan coastal communities and wildlife, the Trump administration is pushing extractive marine activities on these irreplaceable seascapes for nothing but short-term profit,” Freeman added.
In addition to Alaska, the Trump administration has proposed exploring deep-sea mining across millions of hectares of fragile Pacific ecosystems, including areas around the Northern Mariana Islands and Guam – a plan that has drawn backlash from the US territories.
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