For more than a decade, scientists have been on a persistent quest to identify the cause of a gruesome and wide-ranging disease, one that causes the arms of sea stars to twist and fall off, their insides to ooze out, and their bodies to turn to mush, followed by an untimely death. 

In August, a team of researchers announced the discovery of a single species of bacteria believed to be responsible for the devastating sea star wasting disease. This critical discovery has thrown open the doors to dozens of upcoming studies focused on fighting the disease and restoring damaged ecosystems. 

The new findings have ignited hope that coastwide populations of the sunflower sea star, decimated by the disease and nearly extinct in California, might someday recover and return to their important ecological role along the West Coast.

Now that the identity of the mysterious bacteria, Vibrio pectenicida, has been established in the sunflower sea star, scientific investigations can explore how the disease spreads so rapidly, including the role of warm water in outbreaks among many sea star species. Scientists hope to study potential “reservoir species” to learn if sea stars can become infected from clams and other prey that may be carriers of the disease.

The new findings enhance an ongoing search for individual sea stars that might be immune, or at least somewhat resistant, to the infection. And, using advanced genetic techniques, researchers can now examine the potential of incorporating resistance into sea star populations, while assessing the pace of natural recovery versus out-planting sea stars grown under controlled conditions.

“A huge part of this story is the really, really effective collaboration among our research team,” said Drew Harvell, a marine epidemiologist who has been a central figure in sea star research since the wasting disease was first reported in June 2013. “I am incredibly proud of this study (to identify the pathogen), because it really covered the ground necessary to show that a microbe is the causative agent.”

The teamwork demonstrates the power of modern scientific methods, with layers of expertise and advanced laboratory equipment building upon a foundation of past discoveries. Some 15 researchers, each providing a piece of the puzzle, are listed as authors in a paper published Aug. 4 in the journal Nature Ecology and Evolution. Many of the researchers have signed onto future studies, optimistic that they will come to understand the disease process and help restore sunflower and other sea star species to their rightful places in the ecosystem. 

A rapid devastation

In June 2013, a mysterious disease burst onto the scene with swift and devastating effects to sea creatures we commonly call starfish. First reported along the Washington Coast, the affliction was cautiously described as a “wasting syndrome” because its cause was unknown.

In a little more than a year, sea star wasting disease was well established, wiping out millions of sea stars from Canada to Mexico. From the beginning, ecologists expressed concern about long-term effects, not just on the populations of devastated species but on entire ecosystems.

The most afflicted species, the ochre star (Pisaster ochraceus) and sunflower star (Pycnopodia helianthoides), were long understood to play central roles in the structure and function of marine ecosystems, thus gaining stature as “keystone species.”

Harvell, a professor of ecology and evolutionary biology at Cornell University, had been working at the University of Washington’s Friday Harbor Lab when the disease showed up suddenly in the San Juan Islands during the summer of 2014. Leading a team of graduate students in coordination with other researchers, Harvell tracked the progress of the outbreak. She called it a “sentinel of change” that could lead to an ecological upheaval. By fall that year, more than half the sea stars around San Juan Island were dead, with some survey sites experiencing 95 percent mortality for sunflower stars.

Elsewhere, the disease raged on, reaching Alaska’s Aleutian Islands by 2016. In all, more than 20 species of sea stars were affected, as the disease became recognized as the world’s largest known marine epizootic — the scientific term for epidemic when referring to non-human animals.

Most severely affected was the sunflower star, largest of all the sea stars except for Midgardia xandaros, a rare deep-ocean star with spiderlike arms. The sunflower star can grow to three feet across, and individuals may have up to 24 firm but flexible arms displaying one or more shades of purple, orange, brown, yellow or pink. 

The wasting disease was so devastating that the sunflower star was declared critically endangered by the International Union for Conservation of Nature in 2020. 

“The species is now extremely rare across much of the outer coast of the contiguous United States and Mexico, a swath of 2,500 kilometers (1,553 miles) of coastline,” states the IUCN assessment for the endangered listing, also known as the IUCN Red List.

The decline of the sunflower star population was estimated at 99 to 100 percent along the U.S. West Coast, except for the Salish Sea where the loss was 92 percent, according to a 2021 study, which notes that large stretches of coastline in California and Oregon became devoid of the species altogether. A vast amount of data was compiled, not only from organized research teams but also from a large number of volunteer divers following scientific protocols.

These losses have disrupted the food web and contributed to the decline of critical kelp habitats, which support an immense number of marine creatures. Indirectly, kelp forests also contribute to the economy through commercial and recreational fisheries, while protecting shorelines from strong waves.   

Sunflower stars consume a wide variety of prey, including snails, clams, crabs, other sea stars, and most notably sea urchins, which feed on kelp. Without sea stars around to control the sea urchin population, kelp forests have experienced severe declines in many areas, including the San Juan Islands and other parts of Puget Sound. In some documented areas in Northern California, for example, sea urchins multiplied 60 times over, while healthy kelp habitat declined by more than 90 percent during unusually warm conditions.

Before 2013, a decline in the population of sea otters — another sea urchin predator — elevated the sunflower star to a critical role in maintaining the kelp forest community. But after 2013, sea star wasting disease and a boom in the sea urchin population seem to have triggered a widespread disruption in normal ecological processes, wiping out food and shelter for a variety of species in many locations. Areas of the seabed devoid of vegetation, now dominated by spiky sea urchins, have become known as “urchin barrens.”

Understanding what was at stake, researchers wasted no time in looking for a cause of the disease. In 2014, microbiologists at Cornell University published a paper implicating a specific virus as a likely cause. It appeared that a viral-sized organism was to blame, they said, and experiments showed a greater abundance of a specific densovirus in diseased sea stars than in healthy ones.

Later studies, however, cast doubt upon that pathogen. One study identified an entirely different densovirus in sea stars in the Atlantic Ocean, while on the West Coast viral loads were shown to be inconsistent with the severity of disease. Some healthy stars were found to harbor the virus without effect. And so the mystery remained.

Meanwhile, in 2021, the environmental group Center for Biological Diversity, supported by other groups, proposed listing the sunflower sea star as threatened or endangered under the federal Endangered Species Act. Two years later, in 2023, the National Marine Fisheries Service formally proposed to list the species as threatened. A final determination, still pending, could bring heightened protection for the sea stars and their habitats.

The search goes forward 

In 2020, The Nature Conservancy, a scientific-based conservation group, stepped in to provide key funding for a renewed effort to identify the true cause of sea star wasting disease. TNC had been deeply involved in the restoration of kelp forests, and the group understood that the sea star disease was exerting a profound, though indirect, effect on many species. 

Alyssa Gehman, a marine disease ecologist at the Hakai Institute in British Columbia, was enlisted in the disease investigation. Hakai’s parent organization, the Tula Foundation, became a co-sponsor in the research venture. Over the next four years, the project would involve many researchers with a variety of expertise.

“It was a mix of classic disease ecology and cutting-edge genomics,” said Gehman, who first became interested in marine biology in high school in Seattle before focusing on diseases in sea stars at the University of Georgia. She also serves as an adjunct professor for the Institute of Oceans and Fisheries at the University of British Columbia.

The first step in tracking down the sea star disease was to try to replicate earlier studies that pointed to a viral agent. Ground-up tissues from sick sea stars were injected into healthy sea stars, resulting in infection. But if those same tissues were first heated before injection, then healthy stars remained unaffected. This experiment confirmed that the cause was a living organism (in the sense of replication), as widely suspected. 

The next step was to filter homogenized tissues to separate smaller viral particles from larger bacteria and other potential pathogens. That turned out to be easier said than done. Filters were easily clogged by the mash, and the researchers faced a formidable search for one or more causative agents among thousands of microbes throughout the body. 

“It wasn’t very satisfying to work with all that,” Gehman said. 

That’s when the scientists got the idea to run the experiment again, testing just the fluid that fills the body cavity of sea stars. Sea stars function without a heart or complex circulatory system, but their coelomic fluid serves to transport nutrients, immune cells and waste products, somewhat like blood in vertebrate species.

As luck would have it, untreated coelomic fluid alone was found to infect healthy sea stars, Gehman said, and heat treatment could stop the disease in its tracks. Filtering and separating the less cumbersome coelomic fluid led to the discovery that the organism responsible for killing sea stars was not of viral size but rather in the realm of bacteria.

“The question at that point was ‘Can we grow it?’” Gehman said, noting that not all bacteria can be cultured in a lab. 

The answer to this key question would provide the proof of identity that many scientists had been looking for. The classical procedure for identifying the cause of a disease, called Koch’s Postulate, involves isolating a suspect microbe, growing it in culture, and then inducing the disease by infecting a test animal. Finally, the pathogen must be recovered from the animal and shown to match the suspect microbe. This tried-and-true method was developed in the late 1800s by physician and microbiologist Robert Koch, who discovered the cause of tuberculosis, cholera and anthrax.

It turns out that the suspect killer of sea stars could be grown in the lab. Through careful handling to maintain pure cultures, research scientist Amy Chan at the University of British Columbia was able to complete the circle required by Koch’s Postulate and to confirm the cause of the deadly disease in sunflower sea stars.  

Even before that work had begun, the research team had identified a prime suspect, thanks to a genetic investigation by Melanie Prentice, who started her career in forensic science and joined the sea star project in 2023. Her goal was to identify the causative agent, whether virus or bacteria, by sequencing the genetic material — DNA and RNA — found within the coelomic fluid.

“My frame of mind was to come in without any kind of bias,” said Prentice, who grew up in Ontario, Canada, and had been working recently with anthrax in African wildlife. “I was trusting the data to tell the story,” she continued. “I was expecting that we might be dealing with multiple species, such as with pneumonia. I thought the (sea star) disease was a lot more complicated than it turned out to be.”

Prentice sent samples to a sequencing facility, where advanced equipment analyzed the genetic material, which was then sorted with a high-powered computer. When she first looked at the results, Prentice noticed that it showed a lot of bacteria. That wasn’t surprising, nor was significant hits for Vibrio, a genus of bacteria common in marine animals and consisting of numerous species.

One morning, as she was searching through the data, Prentice realized that she was overdue for a meeting with Alyssa Gehman, joined via video conference by team member Grace Crandall. Prentice was eager to show her colleagues how the genetic analysis had zeroed in on Vibrio, a genus of bacteria known to contain a variety of infectious species.

“That is literally just as far as I had gotten,” Prentice recalled. “I was running late, and I had not yet collapsed the data set from genus down to species level.”

Her collaborators watched as Prentice dug deeper into the data. Species after species of Vibrio showed up as blanks, but then she came to one species called Vibrio pectenicida. Nearly all the Vibrio fragments in sick sea stars were aligned to this one species, while healthy sea stars had nearly none. The mystery of the dying sea stars was finally revealed. 

“It suddenly became clear,” Prentice said. “It felt a little surreal. My immediate thought was that I had done something wrong.”

“It was a really exciting moment,” recalled Crandall. “The thing I remember most was looking at Melanie’s face as she realized what we had. “This opens up so many possibilities for future study.”

Because of the previous missteps in announcing a likely viral cause of disease, the research team cautiously engaged in numerous experiments to replicate the disease process using the isolated strain of Vibrio pectenicida. One test involved exposing groups of sea stars to a lower dose of the bacteria, discovering that the higher dose tended to speed up the disease process.

Another major finding involved testing for the presence of V. pectenicida in wild populations using genetic sequencing. In May 2023, the researchers gathered samples from sunflower sea stars in five separate sites in fjords in British Columbia where the wasting disease had not yet showed up. None of those stars contained the bacteria. By October, two of the sites were showing signs of disease. After analysis, the bacteria was detected in 16 percent of sea stars from apparently unaffected sites. But in the affected sites, 74 percent of the normal-looking stars contained the bacteria, while 86 percent of the diseased stars had it. No other significant differences were observed.

The researchers also looked at previous samples from sea stars collected in Southeast Alaska in 2016, when the disease was first arriving. They found similar results, with few sea stars infected with the bacteria if they were living in unaffected areas. A much higher percentage was seen in sea stars from areas affected with disease, with the greatest prevalence among sea stars showing signs of disease. 

Moving beyond recognition

With the cause of the disease now identified, researchers intend to search for sea stars that are naturally immune or at least resistant to the disease. Such sea stars could form the basis of a restored population of once-abundant sunflower stars, either through natural recovery or with the help of human intervention.

The immune system in sea stars is innate and more primitive than that of humans and other vertebrates. In other words, sea stars inherit their genetically coded immune response from their parents; they do not possess the specialized cells that allow humans, for example, to develop immunity to a specific pathogen following exposure. Consequently, a vaccine would not work in sea stars.

Nearly all the sunflower stars exposed to Vibrio pectenicida have died, according to Gehman. Although a few stars have survived initial exposure, they tend to succumb when exposed a second time, offering no hope so far that natural immunity even exists, she said. To be fair, however, she added, the bacterial doses used in past experiments are relatively high.

To learn more about disease response, a new “challenge” experiment was recently launched. It involves exposing sea stars to a wide range of doses of the bacteria, as well as a variety of temperatures. Warm waters have long been implicated in the rapid spread of sea star wasting disease. Now, researchers hope to determine if the sea stars can survive higher bacterial loads if the water is cold enough.

Using genetic technology, the immune and physiological response to such exposures are being tracked by Crandall, a doctoral student at the University of Washington’s School of Aquatic and Fishery Sciences. 

Crandall currently is analyzing genetic data from a 2023 experiment that measured progress of disease in different sea star species by determining which genes became activated at certain times. She found that, while essentially all the sunflower stars got sick and died during the 60 days of testing, a fair number of ochre stars survived, while leather stars (Dermasterias imbricata) showed no outward signs of disease.

“I’m hoping to get an idea what is going on with the immune response,” said Crandall, who recalls a fascination with diseases since elementary school in Aptos, Calif., when she first learned about bubonic plague and other human pandemics. A key question in the current studies, she said, is whether leather stars are launching a successful immune response or perhaps avoiding infection thanks to their soft, leathery skin coated with a layer of mucous.

“What is the difference between the control (unexposed) and the exposed leather stars?” she asked. “I think we will be able to see the different expression patterns in the genes.”

The sudden discovery of the causative agent of sea star wasting disease has raised a variety of questions about the bacteria itself, which is considered a relatively new species. A strain of Vibrio pectenicida was first isolated from a particular species of scallop during the 1990s, when outbreaks of disease occurred in a French scallop hatchery. The bacteria was given its name in a 1998 journal article, after the isolated bacteria was found to be related but distinct from other Vibrio species. The name comes from the Latin “Pectin” (the genus of scallops) and “-cida” (which means killer), so the literal meaning is “killer of scallops.”

More than a dozen other species of Vibrio were already well known to science, among them:

• V. cholerae, which causes cholera in humans. This pathogen is associated with multiple human pandemics over the past 200 years. The potentially deadly diarrheal disease often spreads by drinking contaminated water.
• V. vulnificus, which causes septicemia and flesh-eating infections in humans. It may be spread through contaminated seawater or from eating undercooked shellfish.
• V. parahaemolyticus, which causes vomiting and diarrhea in humans, is associated with eating undercooked fish and shellfish, particularly raw oysters. During summer months. Washington state health authorities test for the bacteria in commercial shellfish and issue warnings when levels become high.
• V. anguillarum, which can be deadly to fish and shellfish, has been blamed for severe economic losses in aquaculture operations throughout the world.

Although many Vibrio species thrive in warm water, spurred on by climate change, much more needs to be learned about this killer of sea stars, said Norah Eddy, associate director of the Oceans Program for The Nature Conservancy. 

“Where did it come from, and why is it so pervasive?” she asked. “Did its arrival coincide with a warm-water event?”

TNC intends to fund research to delve into those questions and more during the coming months, she said. So far, no researchers have been chosen for the investigation into the bacteria itself, she added. Proposed work will include coastwide water sampling to test for the presence of the organism, determine if “hot spots” exist and examine its genetic signature. 

Like most Vibrio, V. pectenicida appears to grow and multiply in open waters when conditions are right. In previous scallop research, the bacteria was found to produce a toxin. So far, it is unclear whether its toxin production is affected by environmental conditions, such as other Vibrio species that favor warmer water.

Some of the upcoming work on the bacteria, along with further investigations into sea stars, will be funded by the Pacific Coast Ocean Restoration Initiative, formed last year by The Nature Conservancy with a three-year, $18 million grant from the National Oceanographic and Atmospheric Administration. The initiative is designed to recover kelp forests and rocky reef ecosystems along the California coast, including specialized work on sunflower sea stars and white abalone. The initiative brings together state agencies, nonprofit groups, academic institutions and others.

Shaping a response

After years of apparent absence along the Oregon and California coasts, sunflower sea stars began to be seen by divers and tidepool watchers in 2023. Most of the sightings have been of smaller juvenile stars, raising questions about the parents. Were adult sea stars hanging out in a place that escaped observation, perhaps deep waters? Or did free-floating larvae drift from areas farther north, where adult sea stars were more abundant?

In either case, such survivors and their offspring raise tantalizing questions about their possible resistance to sea star wasting disease, said Lauren Schiebelhut, an evolutionary ecologist who has been studying genetic changes brought about massive die-offs in a variety of species.

“I’m very interested in trying to document this natural recovery,” said Schiebelhut, a former project scientist at the University of California Merced, now working with the Sunflower Star Laboratory in Monterey while serving on the faculty of Clovis Community College in Fresno.

As a graduate student in 2012, before the outbreak of sea star wasting disease, Schiebelhut was investigating a massive die-off of invertebrates in North-Central California caused by a toxic algal bloom. By chance, she collected tissue samples for genetic analysis from a variety of surviving species — including the ochre sea star. These samples are among the few available taken from ochre stars in California immediately before the wasting disease took a serious toll on the population.

Now, Schiebelhut would like to compare genetic differences between the pre-disease ochre stars to those recovering in California waters. The results might reveal not only the parental source of the recovering population but also how the disease may have altered its genetic makeup. Further tests might reveal a resistance to disease.

Schiebelhut, working with fellow researcher Mike Dawson, previously produced a “reference genome” for sunflower stars by assembling the DNA from a select sea star. This work, supported by the conservation group Revive and Restore, can now be used when analyzing the genome of any other sunflower star.

For the most part, sunflower stars along the West Coast appear very much alike genetically. That’s likely because they are broadcast spawners, releasing eggs and sperm into the water, where fertilization takes place. The fertilized eggs develop into larvae, which can drift for hundreds, even thousands of miles before settling down. The result is a well-mixed coastwide population.

Still, Schiebelhut’s studies have shown that ecological perturbations, such as disease or other widespread forces, can result in slight, detectable alterations in the genome within an affected area. This is often the result of natural selection, as a particular gene variant confers resistance to disease or other environmental pressures. 

Even though natural recovery of sunflower stars may be underway, some experts argue that such recovery could be too slow to restore ecological health in a reasonable time. The alternative is to breed large numbers of sea stars in captivity and then release them at an appropriate time.

That’s the kind of work taking place at the UW’s Friday Harbor Laboratories, where research scientist Jason Hodin developed techniques for the world’s first captive-breeding program for sunflower stars, taking the process from fertilization to adulthood and then breeding those sea stars at the Friday Harbor facility, known for advances in marine embryology since 1924.

Figuring out how to feed the stars at all life stages, as well as identifying optimal water conditions, was no small task, Hodin said. In the lab, fertilized eggs develop into embryos, soon followed by free-swimming larval stages. Young larval stars, which are fed algae, settle out and undergo metamorphosis to become juveniles, which are then fed young sea urchins. The sea urchins are produced in the lab’s unique cultivation operation dedicated to feeding the sea stars. 

“If they don’t find food, they start eating each other,” Hodin noted, “so we’re motivated to find the right food for them. We have been working ourselves to the bone trying to raise enough urchins to feed the sea stars.”

One thing he has learned in the process is that juvenile sunflower stars may be as important ecologically as adults, when it comes to controlling sea urchins in the wild, where they have devastated kelp beds. If an adult sea star can help reduce the damage to kelp by eating one adult sea urchin per day, consider that a juvenile sea star may eat up to 18 baby sea urchins in a day. 

The predatory role of tiny sea stars has not been fully appreciated in many food web models, Hodin said.

Eventually, the sea stars growing in the lab become large enough to eat baby clams, which can be purchased from outside hatcheries. “The day they graduate to clams, we can go on vacation,” Hodin joked about the effort it takes to produce sea urchins. 

The successful captive-rearing program, which was started in 2019, was able to release sea stars the past three summers. In 2023, 48 sea stars, 1 and 2 years old, were separated by age group and kept in six cages at three locations. When retrieved later that year, all were healthy and growing.

In 2024, one- and two-year-old sea stars were released without confinement offshore near the lab, where researchers observed their dispersal and growth. Recently, 28 stars — 3-, 4- and 5-year-olds — were released into an urchin barren, where kelp had been displaced by sea urchins. Researchers are monitoring the density of urchins in that area as the sea stars move around.

Besides the localized propagation efforts, the Friday Harbor lab has been a source of healthy sea stars for experiments by Gehman and others working at the U.S. Geological Survey’s field station on Marrowstone Island near Port Townsend. The UW lab also could be one source of sea stars if a major out-planting program were launched to boost sea star numbers in chosen locations. 

The importance of the cultivation techniques perfected by Hodin and his team is not lost on other facilities that have accepted the challenge of breeding endangered sunflower stars as a hedge against extinction. Nine facilities from California to Illinois — five aquariums, four laboratories and a museum — have successfully bred sunflower stars. Others are raising captured stars that could potentially be used in captive breeding programs.

These institutions are coordinated with research and education efforts through the SAFE Species Program, organized by the Association of Zoos and Aquariums. SAFE, which stands for Saving Animals From Extinction, currently is working to recover 33 marine and terrestrial species. See “SAFE Sunflower Sea Star Program Plan (PDF).”

In a related effort, the frozen larvae of sunflower stars from Alaska and Washington are being stored through cryopreservation at the Henry Doorly Zoo and Aquarium in Omaha, Neb. If needed in the future, these larvae and others to be added later to the larval bank could be thawed and grown to adulthood. A similar program involves storing frozen sperm at facilities in Southern California under a partnership that includes San Diego Zoo Wildlife Alliance.

An important goal for all these efforts is to maintain genetic biodiversity for the wild population, which may have been altered by the devastating sea star wasting disease, according to Schiebelhut. Another catastrophic event, such as a major heat wave, could further reduce diversity.

If resistant sea stars can be found, the impulse might be to cultivate large numbers for introduction into the wild, she continued. But one should try to make sure that genetic variation is not lost, as a specific gene variant might be needed to survive other diseases or environmental changes. 

“We wouldn’t want to inbreed traits that would make a bunch of sea stars more vulnerable,” she added. “The sunflower star is a test case. It serves as a good template for thinking about future events (for all endangered species).”

Mapping the genome of all sunflower stars in captivity and comparing the results to the general population could help experts decide which stars to cross with others in ways that benefit the wider population, she said.

Since vaccines are ineffective for sea stars, researchers are considering whether to search for a specific bacteriophage capable of attacking the bacteria responsible for sea star wasting disease, she said. Bacteriophages are viruses that infect and destroy bacteria by hijacking their own molecular machinery.

Researchers in California were investigating a serious disease outbreak in commercial abalone farms when they discovered a viral ally in the effort to increase survival among the greenlip abalone. In the laboratory, the bacterial disease, caused by Vibrio harveyi, could be prevented in abalone treated with the phage. The authors of the study, published in the journal Aquaculture, said their methods would need to be scaled up for industrial use.

Although bacteriophage therapies have been developed to help in the battle against disease in some captive populations, experts say many challenges face researchers who would like to treat species living in wide-open marine environments.

Pathways to the future

In February 2025, 19 experts involved in sea star recovery came together in Santa Barbara, Calif., to discuss how conservation breeding programs and related research could help to recover the endangered sunflower stars. The strategy (PDF) they developed focused on three actions:

• Expand cryobanking, in which frozen embryos, eggs or sperm are catalogued and stored to preserve maximum genetic diversity. The reproductive samples would be collected from sunflower sea stars across their entire range, as well as from zoos and aquaria, for incorporation into lab-bred sea stars released to the wild.
• Conduct multi-generational “challenge trials” to search for disease-resistant family lines, genetic traits or external conditions that can boost resilience.
• Search for bacteriophages or probiotic compounds associated with an increased level of survival in the larger sunflower star population. If found, such biotic treatments could be used to treat laboratory-bred sea stars released to the wild.

The group gathered for the workshop generally acknowledged that conservation breeding in labs involves some important decisions before large-scale out-planting takes place, but breeding programs are likely to increase the chances of maximizing disease resilience, genetic diversity and ecological health. 

That workshop, focused on breeding programs, was an outgrowth of a 2022 report titled “Roadmap to Recovery for the Sunflower Sea Star (PDF),” a wide-ranging status report topped off with a list of recommendations to advance species recovery. Credit for the report goes to 27 leading experts with help from a dozen other reviewers.

In addition to studying the disease process, the group called for a greater understanding of regional populations and environmental conditions in specific locations along the West Coast. 

“Demographic and genetic recovery criteria are needed to inform if natural recovery is occurring and when and where management actions are needed to guide the recovery of sunflower sea star populations,” the report states. “While there are data gaps identified, there is enough information to begin establishing regionally based goals and criteria and modeling population dynamics…

“Given the risk for further declines, we recommend an emergency response plan be prepared for each region. The plan should carefully lay out triggers for responses and describe the facilities and personnel that are available should rescue be needed to avoid mortality in the wild due to Sea Star wasting disease or heatwaves.”

Nora Eddy of The Nature Conservancy said more workshops are planned to keep all participants informed of new findings and generate innovative ideas.

“There are still boundless questions,” she said. “We should be squarely focused on thoughtful and strategic actions that will get us to the next phase of species recovery.”