Latest news with #Vibriopectenicida
Economic Times
3 days ago
- Science
- Economic Times
Death of 5 billion sea stars mystery solved: Scientists reveal what killed the iconic star-shaped creatures
Scientists say they have finally discovered the cause behind the death of more than 5 billion sea stars along the Pacific coast of North America, solving a mystery that has lasted over a decade. As per an AP report, starting in 2013, a mysterious disease called sea star wasting disease led to a massive die-off of sea stars (often called starfish), from Mexico to Alaska. More than 20 species were affected, with the sunflower sea star hit hardest, losing nearly 90% of its population in just five years. 'It's really quite gruesome,' said Alyssa Gehman, a marine disease expert at the Hakai Institute in British Columbia, who worked on the new research. 'Healthy sea stars have puffy arms sticking straight out, but with the disease, they develop lesions and then their arms actually fall off.' The cause? A bacteria known as Vibrio pectenicida, the same type that also affects shellfish, was identified in a new study published in the journal Nature Ecology and Evolution. 'This solves a long-standing question about a very serious disease in the ocean,' said Rebecca Vega Thurber, a marine microbiologist at the University of California, Santa Barbara, who was not part of the study. For years, scientists believed the cause might be a virus, particularly a densovirus. But further research revealed that this virus exists in healthy sea stars too, and wasn't responsible for the had also missed the real cause earlier because they mainly studied dead sea stars, which no longer had the internal fluid needed for proper analysis. This time, scientists focused on coelomic fluid, the liquid inside living sea stars, and found the harmful bacteria there.'It's incredibly difficult to trace the source of environmental diseases, especially underwater,' said microbiologist Blake Ushijima from the University of North Carolina, who wasn't involved in the study. He called the research 'really smart and significant.'Now that the cause is known, scientists believe they can start efforts to protect and restore sea star to Melanie Prentice, co-author of the study, researchers can now test which sea stars are still healthy, explore breeding in captivity, and move healthy individuals to areas where the population has collapsed. They may also test whether some sea stars have natural immunity, and whether probiotics could help protect work is essential not just for the sea stars, but for the entire marine ecosystem. Sunflower sea stars are known for eating sea urchins, which helps keep their numbers in check. Since the sea stars have vanished, sea urchins have taken over, destroying about 95% of kelp forests in Northern California within ten years. These kelp forests are often called the 'rainforests of the ocean,' and they provide food and shelter for fish, sea otters, seals, and many other marine species. 'Sunflower sea stars look sort of innocent when you see them,' said Gehman, 'but they eat almost everything that lives on the bottom of the ocean. They're voracious eaters.'Now, with this new breakthrough, scientists hope to bring sea star numbers back, and help restore the Pacific's kelp forests. Inputs from AP
Time of India
4 days ago
- Health
- Time of India
What led to the death of billions of starfish in over a decade? Scientists might finally have the answer
After more than ten years of searching, scientists say they have finally solved the mystery behind a catastrophic epidemic that wiped out over five billion sea stars along the Pacific coast of North America. A newly identified bacterium is believed to be responsible, marking a breakthrough in efforts to save these iconic marine animals. Since 2013, a rapidly spreading illness known as sea star wasting disease has caused massive die-offs from Mexico to Alaska, affecting more than 20 different species. The sunflower sea star was among the worst hit, its population declined by about 90% within the first five years of the outbreak. 'It's really quite gruesome,' said Alyssa Gehman, a marine disease ecologist at the Hakai Institute in British Columbia, Canada, who helped identify the cause. She described how healthy sea stars usually have 'puffy arms sticking straight out,' but once infected, they develop lesions and eventually 'their arms actually fall off.' The answer, finally published in the journal Nature Ecology and Evolution, points to a bacterium, Vibrio pectenicida, which is also known to infect shellfish. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Become Fluent in Any Language Talkpal AI Undo The findings represent 'a long-standing question about a very serious disease in the ocean,' said Rebecca Vega Thurber, a marine microbiologist at the University of California, Santa Barbara, who was not part of the study. Identifying the true culprit wasn't easy. According to Melanie Prentice of the Hakai Institute, a co-author of the study, earlier efforts were misled by a densovirus, which researchers initially thought was the cause. That virus, however, turned out to be a normal resident of healthy sea stars. Another problem with previous studies was that they often used tissue samples from dead sea stars, which no longer contained coelomic fluid, the bodily fluid surrounding internal organs where the disease agent would be active. This latest research took a different approach. Scientists focused on analysing that specific coelomic fluid, and it was there that they discovered the bacterium Vibrio pectenicida. Blake Ushijima, a microbiologist at the University of North Carolina, Wilmington, who was not involved in the study, praised the team's 'really smart and significant' detective work. He acknowledged the unique challenge of identifying marine pathogens, saying it is 'immensely difficult' to trace environmental disease sources, 'especially underwater.' Now that the root cause has been pinpointed, scientists hope they can act to prevent further losses. Prentice said researchers might now begin testing the remaining sea stars for overall health. They're also considering captive breeding or relocating healthy individuals to regions where sunflower sea stars have disappeared. Scientists are also exploring whether certain populations may have natural immunity, or whether treatments such as probiotics could help strengthen resistance to the disease. The stakes go far beyond just the sea stars themselves. These creatures are key predators in kelp forest ecosystems. Their disappearance has led to ripple effects throughout the food web, as kelp forests provide shelter and food for fish, sea otters, and seals. Restoring sea star populations could help regrow what Thurber described as 'the rainforests of the ocean.'
Indian Express
4 days ago
- Health
- Indian Express
In 12 years, 5 billion starfish ‘wasted away' from a mysterious disease: How culprit was finally found
Twelve years after a mysterious disease started killing off starfish in droves — more than 5 billion are estimated to have died since 2013 — scientists have found the culprit to be a bacterium. The starfish, or sea stars, of various species were dying off a wasting disease, in which their limbs fell off and their bodies melted away to leave just a pile of gunk. The epidemic was found along the Pacific coast of North America, all the way from the freezing waters off Alaska to the warmer shores of Mexico. Till a few years ago, scientists believed a virus was causing the outbreak. However, a study published in the journal Nature on August 5 said the starfish were falling victim to Vibrio pectenicida, which is related to the bacteria that causes cholera in humans. Why was this epidemic a cause for major concern, and how has the bacterium responsible finally been found? The problem The wasting disease was impacting whole populations of starfish, but the worst affected were sunflower sea stars, which lost almost 90 per cent of their population. Starfish perform a vital function in the marine ecosystem, maintaining a stable food chain. When billions of starfish died, the population of sea urchins, which they feed on, exploded. These sea urchins started eating away whole forests of kelp, a seaweed other marine animals thrive on and which helps sequester carbon. It was a long process. While studies earlier focused on a virus type called the densovirus, it was later found to occur naturally in some starfish. Also, some studies were examining the tissue samples of the dead starfish, when the bacterium was in fact present in the coelomic fluid, the equivalent of starfish blood. The breakthrough came at the Hakai Institute in British Columbia, Canada, where scientists raised sunflower sea stars in the labs, and then began exposing them to the infected starfish in various ways, like bringing them physically in contact with diseased body parts or injecting mixtures from such parts. It was found that injections passed on the infection, but not when their contents had been treated with heat. In effect, boiling was killing off the cause of the disease, pointing to a bacterium. The scientists then examined the coelomic fluid of both healthy and infected starfish. Dr Alyssa Gehmanopens, co-author of the study, was quoted by the UK's National History Museum as saying, 'When we compared the coelomic fluid of exposed and healthy sea stars, there was basically one thing different: Vibrio. We all had chills. We thought, 'That's it. We have it. That's what causes wasting'.' However, they conducted further confirmatory tests, by injecting the bacterium in healthy starfish, and examining sea water before and after an outbreak. How will this finding help? Understanding the cause of a disease is of course the first step to treating it. Scientists will now see if starfish in the sea can be given probiotics to fight off the bacteria, and if Vibrio-resistant starfish can be grown in labs and introduced into the wild, among other measures. Is there need for caution? Yes. 'It's absolutely critical not to jump the gun…It's really, really hard to do these type of experiments, and particularly the interpretation of it is somewhat difficult,' Cornell marine biologist Ian Hewson told The Washington Post. He pointed out that the study was carried out on only one type of starfish, and also injecting a starfish in a lab may throw up different results from what actually happens in the ocean. To add to this, the environment in an ocean is highly changeable, unlike the controlled surroundings of a lab.
Scientific American
5 days ago
- Health
- Scientific American
Mysterious Illness Decimating Sea Stars Finally Identified
A mysterious illness has killed billions of sea stars in the past decade. After a four-year search, scientists have uncovered the culprit: a bacterium known as Vibrio pectenicida. The team reported its findings this week in Nature Ecology & Evolution. The strange illness is known as sea star wasting disease, and it causes starfish to disintegrate to death. It is the largest marine epidemic among noncommercial species that has ever been documented, and it has affected more than 20 species of sea stars along the Pacific Coast of North America. Approximately 90 percent of sunflower sea stars (Pycnopodia helianthoides) have died from the ailment, so many that they are now a critically endangered species. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Researchers are unsure of where this bacterium came from and why it broke out. But there is evidence that warmer ocean temperatures are linked to bigger outbreaks. In British Columbia, the most severe outbreaks happen late in the summer, says study co-author Alyssa Gehman, a marine disease ecologist at the province's Hakai Institute and the University of British Columbia. And that suggests that temperature and possibly even climate change might affect this disease. 'Sea stars [such as] sunflower stars are really important members of their communities,' Gehman says. When the sunflower sea stars lost about 90 percent of their population, there were huge increases in sea urchins (a prey of sea stars) off the coast of California. The spiny creatures are massive grazers of kelp forests, which are crucial members of marine ecosystems, Gehman says. Underwater kelp forests store carbon and are homes for thousands of species. But once sea urchin populations boomed, there was a widespread loss of kelp forests. To identify the disease, researchers ran more than 20 experiments from 2021 to 2024. In one experiment, they analyzed the genes of eight healthy sea stars and eight infected ones. While sitting in her office and comparing the genetics of the two groups, Melanie Prentice, a research scientist now at the Hakai Institute, thought, 'Gosh, there's so much Vibrio in these wasting sea stars, and there's really not much happening in these healthy sea stars in terms of Vibrio.' After toggling the data to see the specific Vibrio species, she found V. pectenicida in every single one of the wasting sea star samples. To validate the finding, Prentice and her team exposed healthy sea stars to V. pectenicida. From the 20 sunflower stars that the researchers exposed to V. pectenicida at varying doses, only one survived (this sea star was exposed to the lowest dose of the bacteria tested). The rest died from sea star wasting disease, providing the conclusive evidence the team needed, Prentice says. 'If you don't know what it is that's killing them, there's only so much you can do to try and save them,' Gehman says. 'So, there's a bunch of work that we can do now.' One next step is to determine if the pathogen is unique to the sunflower sea star because there are still many other species affected by the disease, says Oregon State University marine ecologist Bruce Menge, who wasn't involved in the study. Prentice and her colleagues hope to breed sea stars that are resistant to the pathogen so they can survive in the wild. It's Time to Stand Up for Science Before you close the page, we need to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and we think right now is the most critical moment in that two-century history. We're not asking for charity. If you become a Digital, Print or Unlimited subscriber to Scientific American, you can help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both future and working scientists at a time when the value of science itself often goes unrecognized.
1News
5 days ago
- Health
- 1News
Scientists say they have solved the mystery of what killed more than 5 billion starfish
Scientists say they have at last solved the mystery of what killed more than 5 billion sea stars off the Pacific coast of North America in a decade-long epidemic. Sea stars – often known as starfish – typically have five arms and some species sport up to 24 arms. They range in colour from solid orange to tapestries of orange, purple, brown and green. Starting in 2013, a mysterious sea star wasting disease sparked a mass die-off from Mexico to Alaska. The epidemic has devastated more than 20 species and continues today. Worst hit was a species called the sunflower sea star, which lost around 90% of its population in the outbreak's first five years. 'It's really quite gruesome,' said marine disease ecologist Alyssa Gehman at the Hakai Institute in British Columbia, Canada, who helped pinpoint the cause. Healthy sea stars have 'puffy arms sticking straight out', she said. But the wasting disease causes them to grow lesions and 'then their arms actually fall off'. ADVERTISEMENT A sunflower sea star is reduced to goo by sea star wasting disease at Calvert Island, British Columbia, Canada, in 2015. (Source: Grant Callegari/Hakai Institute via AP) The culprit? Bacteria that has also infected shellfish, according to a study published today in the journal Nature Ecology and Evolution. The findings 'solve a long-standing question about a very serious disease in the ocean", said Rebecca Vega Thurber, a marine microbiologist at University of California, Santa Barbara, who was not involved in the study. It took more than a decade for researchers to identify the cause of the disease, with many false leads and twists and turns along the way. Early research hinted the cause might be a virus, but it turned out the densovirus that scientists initially focused on was actually a normal resident inside healthy sea stars and not associated with disease, said Melanie Prentice of the Hakai Institute, co-author of the new study. Other efforts missed the real killer because researchers studied tissue samples of dead sea stars that no longer contained the bodily fluid that surrounds the organs. But the latest study includes detailed analysis of this fluid, called coelomic fluid, where the bacteria Vibrio pectenicida were found. ADVERTISEMENT 'It's incredibly difficult to trace the source of so many environmental diseases, especially underwater,' said microbiologist Blake Ushijima of the University of North Carolina, Wilmington, who was not involved in the research. He said the detective work by this team was 'really smart and significant'. Healthy populations of sunflower sea stars are found in the Knight Inlet fjord of the Central Coast of British Columbia, Canada, in 2023. (Grant Callegari) Now that scientists know the cause, they have a better shot at intervening to help sea stars. Prentice said that scientists could potentially now test which of the remaining sea stars are still healthy — and consider whether to relocate them, or breed them in captivity to later transplant them to areas that have lost almost all their sunflower sea stars. Scientists may also test if some populations have natural immunity, and if treatments like probiotics may help boost immunity to the disease. Such recovery work is not only important for sea stars, but for entire Pacific ecosystems because healthy starfish gobble up excess sea urchins, researchers say. With a lack of predatory sunflower sea stars, sea urchins proliferate in Hakai Pass, British Columbia, Canada, in 2019. (Source: Grant Callegari/Hakai Institute via AP) ADVERTISEMENT Sunflower sea stars 'look sort of innocent when you see them, but they eat almost everything that lives on the bottom of the ocean', said Gehman. 'They're voracious eaters.' With many fewer sea stars, the sea urchins that they usually munch on exploded in population – and in turn gobbled up around 95% of the kelp forest s in Northern California within a decade. These kelp forests provide food and habitat for a wide variety of animals including fish, sea otters and seals. Researchers hope the new findings will allow them to restore sea star populations – and regrow the kelp forests that Thurber compares to 'the rainforests of the ocean'.
