New eDNA tool to help track recovery of sunflower sea star, a Pacific Coast ‘apex predator’
Summary
<div class="c-field c-field--name-title c-field--type-string c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item">New eDNA tool to help track recovery of sunflower sea star, a Pacific Coast ‘apex predator’ </div></div></div> <div class="c-field c-field--name-field-image c-field--type-entity-reference c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"><figure> <div class="c-field c-field--name-field-media-image c-field--type-image c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"> <img alt="A scuba diver takes a close up look at a large, purple and orange sunflower sea star in Puget Sound." height="717" src="https://www.noaa.gov/sites/default/files/styles/landscape_width_1275/public/2026-06/img-3061_orig.jpg?h=48a5e842&itok=OEvrias8" title="A scuba diver takes a close up look at a large, purple and orange sunflower sea star in Puget Sound. (Image credit: Courtesy of Zachary Gold)" width="1275" /> </div></div></div> <figcaption> <div> <div class="caption-credit"> <div class="c-field c-field--name-field-file-caption-formatted c-field--type-text-long c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"><p>Michael Peñuelas, a Seattle scuba diver, examines a large sunflower sea star in the Edmonds Marine Park in Puget Sound, Washington, in 2021. <span class="credit">(Image credit: Courtesy of Zachary Gold)</span></p></div></div></div> </div> </div> </figcaption> </figure> </div></div></div> <div class="c-field c-field--name-field-publication-date c-field--type-datetime c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"><time datetime="2026-06-25T12:00:00Z">June 25, 2026</time> </div></div></div> <div class="c-field c-field--name-field-body c-field--type-entity-reference-revisions c-field--label-hidden"> <div class="c-field__content"><div class="c-field__items"><div class="c-field__item"> <section class="l-section paragraph paragraph--type-rich-text paragraph--display-mode-default paragraph--width-body-indent-none"> <div class="l-section__content"> <div id="paragraph-id-49712"> <div class="c-field c-field--name-field-body-formatted-long c-field--type-text-long c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"><p dir="ltr">A wasting disease that surged during the intense 2013-2016 Pacific marine heatwave known as <a href="https://www.pmel.noaa.gov/news-and-media/pmel-in-the-news/warm-blob-pacific-ocean-linked-weird-weather-across-us">the Blob</a> decimated numerous species of sea stars and triggered the collapse of vast coastal kelp forests from the Aleutians to the Baja Peninsula. One of the species most affected was the <a href="https://www.fisheries.noaa.gov/species/sunflower-sea-star">sunflower sea star</a>, an apex predator that feeds on kelp grazers like sea urchins. </p><p dir="ltr">As captive breeding programs and the discovery of additional sea star refuges, (like the one found in <a href="https://sanctuaries.noaa.gov/notes/2026/sunflower-star-sighting.html">Greater Farallones National Marine Sanctuary in August 2025</a>) fuel hopes for the sunflower sea star, researchers at NOAA’s Pacific Marine Environmental Laboratory (<a href="https://www.pmel.noaa.gov/">PMEL</a>) have developed a rapid <a href="https://www.pmel.noaa.gov/ocean-molecular-ecology/news-story/unlocking-power-edna-marine-conservation">environmental DNA (eDNA)</a> detection method that dramatically improves scientists’ ability to monitor the sea star species’ health and recovery. </p><p dir="ltr">“By analyzing tiny amounts of genetic material they shed into the water, we can now identify these large but elusively rare sea stars without ever seeing them,” said Zachary Gold, a scientist who leads PMEL’s <a href="https://www.pmel.noaa.gov/ocean-molecular-ecology/">Ocean Molecular Ecology</a> program. “This opens the door to efficiently monitoring the recovery of this species, especially at deeper depths and sites that are difficult for divers to survey.” </p><figure> <article> <div class="c-field c-field--name-field-media-image c-field--type-image c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"> <img alt="A large purple and orange sunflower sea star in the Edmonds Marine Park in Puget Sound, Washington state" height="759" src="https://www.noaa.gov/sites/default/files/2026-06/img-3069_orig-2.jpg" title="A large purple and orange sunflower sea star in the Edmonds Marine Park in Puget Sound, Washington state (Image credit: Zachary Gold/NOAA Pacific Marine Environmental Laboratory )" width="770" /> </div></div></div> </article> <figcaption><span class="caption-text">A large purple and orange sunflower sea star living in the Edmonds Marine Park in Puget Sound, Washington state, in 2021.</span> <span class="credit">(Image credit: Zachary Gold/NOAA Pacific Marine Environmental Laboratory )</span><div class="image-download"><a class="image-download-link" href="https://www.noaa.gov/media/image_download/56334589-0e92-48b0-a8de-383cd8160abd">Download Image</a></div></figcaption> </figure> <p dir="ltr">The eDNA method, which can detect as few as a handful of copies of DNA in a liter of seawater, is less expensive, more sensitive and more efficient for rapid assessments than dive surveys. Results can be obtained in as little as one or two days and can be followed up by visual confirmation. After one recent eDNA detection, for example, divers in Northern California’s Noyo Bay were able to find one juvenile sunflower sea star the size of a teacup.</p><h2><span style="font-size: 22px;">Restoring balance to coastal kelp forests: What sunflower stars can do</span></h2><p dir="ltr">The once-abundant sunflower star, <a href="https://www.fisheries.noaa.gov/feature-story/noaa-fisheries-proposes-listing-sunflower-sea-star-threatened-under-endangered-species">now proposed for listing under the Endangered Species Act,</a> is, like the sea otter, a voracious predator of bottom-dwelling sea urchins. Working together, sunflower stars, sea otters, and other healthy predator communities feed on sea urchins and other kelp grazers to <a href="https://sanctuaries.noaa.gov/news/2026/restoring-balance.html">help keep vital kelp forest ecosystems in balance</a>. </p><p dir="ltr">Kelp forests are one of the most biologically productive and economically rich ecosystems on Earth. They act as vital marine nurseries and high-value habitats for hundreds of species across global coastlines. Kelp forests filter nutrient pollution and provide valuable habitat that supports fish populations and commercial fisheries.</p><p dir="ltr">In healthy kelp forests off California, sea urchins are part of the natural ecosystem. They graze on algae and help recycle nutrients along the seafloor. But when the balance is disrupted, urchin populations can surge and the entire system can begin to unravel. Their populations can increase exponentially, converting lush, vibrant kelp forests to barren aquatic deserts. Even after The Blob receded, starving sea urchins prevented the rebound of hundreds of miles of collapsed kelp ecosystems by continually grazing off new growth.</p><h2><span style="font-size: 22px;">Hold captive: Bringing back the stars of the sea</span></h2><p dir="ltr">In response to the sea star wasting disease outbreak, scientists brought surviving sunflower stars into captivity to protect the species and research the disease. This critical intervention enabled two important discoveries: how to successfully spawn sunflower stars in captivity, and the identification of a novel bacterium called <a href="https://www.youtube.com/watch?v=oG5uALXSm_E">Vibrio pectenicida</a> that served as the primary driver for the disease.</p><p dir="ltr">Captive breeding also helped scientists validate their tool for detecting these sea stars in the wild. The team tested their eDNA method in laboratories, in aquaria, and in the ocean, paired with traditional dive surveys. The results were clear: Not only was the test effective in identifying the presence or absence of the species, but the more sunflower stars the divers saw, the more DNA the method detected. </p><h2><span style="font-size: 22px;">Monitoring and managing sea star recovery</span></h2><p dir="ltr">In recent years, scattered sightings in <a href="https://olympiccoast.noaa.gov/">Olympic Coast National Marine Sanctuary</a> and in Northern California tidepools have raised hopes that sunflower stars may be repopulating portions of their native range. In 2026, a team including NOAA scientists, assessed 39 California sites, including former hotspots, locations with recent anecdotal reports, and areas within and adjacent to marine protected areas.</p><p dir="ltr">Using the eDNA method, researchers detected sunflower stars at six distinct sites spanning Mendocino, Sonoma, and San Mateo counties — including the first detection of the species south of San Francisco in a decade.</p><p dir="ltr">Recently, <a href="https://www.pmel.noaa.gov/ocean-molecular-ecology/">PMEL’s Ocean Molecular Ecology program</a> has been employing this tool to support conservation partners. Researchers in Olympic Coast National Marine Sanctuary are adding eDNA detections to their visual surveys to modernize survey efforts.</p><p dir="ltr">“The development of a targeted, validated detection method for the sunflower sea star adds to NOAA’s growing inventory of tools to monitor and evaluate species of concern or importance,” said Krista Nichols, a genetics program manager with <a href="https://www.fisheries.noaa.gov/">NOAA’s National Marine Fisheries Service</a>. “For sea stars in particular, the use of eDNA could be a game changer for this struggling apex predator.” </p></div></div></div> </div> </div> </section> </div></div></div></div> <div class="c-field c-field--name-field-media-contact c-field--type-text-long c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item"><p> </p><p>Media contact</p><p>Theo Stein, NOAA Research Public Affairs, at <a href="mailto:theo.stein@noaa.gov">theo.stein@noaa.gov</a> </p></div></div></div> <div class="c-field c-field--name-field-node-focus-area c-field--type-entity-reference c-field--label-hidden"> <div class="c-field__content"><div class="c-field__items"><div class="c-field__item"><a href="https://www.noaa.gov/research">Research</a> </div><div class="c-field__item"><a href="https://www.noaa.gov/fisheries">Fisheries</a> </div></div></div></div> <div class="c-field c-field--name-field-tags c-field--type-entity-reference c-field--label-hidden"> <div class="c-field__content"><div class="c-field__items"><div class="c-field__item"><a href="https://www.noaa.gov/topic-tags/marine-life">marine life</a> </div><div class="c-field__item"><a href="https://www.noaa.gov/topic-tags/pacific-ocean">Pacific Ocean</a> </div></div></div></div> <div class="c-field c-field--name-field-sidebar-next-to-intro c-field--type-boolean c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item">0</div></div></div> <div class="c-field c-field--name-field-updates c-field--type-entity-reference-revisions c-field--label-hidden"> <div class="c-field__content"><div class="c-field__items"><div class="c-field__item"></div></div></div></div> <div class="c-field c-field--name-field-suppress-hero-image c-field--type-boolean c-field--label-hidden"> <div class="c-field__content"><div class="c-field__item">Off</div></div></div>