A total of 754 million domestic passenger trips were made in China in the first seven days of the 8-day National Day and Mid-Autumn Festival holidays, a year-on-year increase of 78.9%. Holiday tourism generated 668.1 billion yuan ($92.80 billion), up 132.6% year-on-year, official data showed on Friday.
After 276 days in orbit, China's reusable experimental spacecraft landed at its planned site at the Jiuquan Satellite Launch Center in Northwest China's Gansu Province on Monday, and Chinese space watchers said it was a milestone in China's efforts to develop a fully reusable space transportation system.
The success is an important breakthrough in China's research on reusable spacecraft technologies, which will provide more convenient and affordable round trips for the peaceful use of space, the Xinhua News Agency said on Monday.
China launched a reusable experimental spacecraft using its Long March-2F carrier rocket from the Jiuquan Satellite Launch Center on August 5, 2022, to test reusable technologies and in-orbit service technologies to support the peaceful use of space, Xinhua previously reported.
China tested the reusable experimental spacecraft in September 2020, and the spacecraft returned to the planned landing site after two days in orbit. The spacecraft was also launched with a Long March-2F carrier rocket.
Chinese authorities have disclosed few details about the craft's technology. So far, no images of the spacecraft or footage of its launch or landing have been disclosed.
Many space lovers compared it to the US Air Force's X-37B, an autonomous Boeing space plane that can remain in orbit for long periods before returning to Earth on its own, saying that the technology used in the experiment is "too advanced to show" on social media.
The reusable spacecraft's technology has evidently matured, considering how much longer it can stay in orbit, Chinese space watchers noted on Sunday.
Song Zhongping, a space expert and TV commentator, told the Global Times on Monday that the reusability of such spacecraft would drastically reduce costs. More importantly, the longer orbiting time means that the spacecraft can perform more complicated missions such as changing trajectory in near-Earth orbit and sending various payloads into orbit.
Judging from the rocket used in the launch, the Long March-2F carrier rocket - which is one of China's most advanced and reliable rockets for manned space flights - the reusable spacecraft may be used in future manned missions, said another space observer, speaking on condition of anonymity.
Given the payload launching capability of the Long March-2F, the spacecraft could weigh around 8 tons, which is very similar to the launch mass for the X-37B at around 5 tons, so that speculation about their similarity is not groundless, the observer said.
The latest test of the reusable spacecraft was the longest, most complicated, and most challenging so far. The record of 276 days in orbit even beat the first mission of the US' X-37B in 2010, which remained in orbit for 224 days, Huang Zhicheng, a space industry expert, told the Global Times on Monday.
At the China Space Conference opening event to mark the April 24 Space of China this year in Hefei, East China's Anhui Province, Wang Wei, an academician of the Chinese Academy of Sciences and director of the research and development department of the state-owned aerospace giant China Aerospace Science and Technology Corp, listed the 10 major scientific and technology problems for the 2023 space development.
Among them is the health monitoring of the power system for the reusable vehicle and an assessment of its service life.
Huang said that one of the many advantages of the reusable spacecraft is that it can land horizontally, which is more comfortable and safer for the crew. Once it's mature, such technology could be applied to suborbital or space tourism, and even super fast point-to-point transportation for people or cargo on Earth.
The US often hypes and smears China's technology breakthroughs as militarization because it sees all breakthroughs by non-Western countries as a threat. This is meant to maintain a technology monopoly, which is unfair to other countries and serves US hegemony, Chinese experts said.
The high-altitude pressurized liable building independently developed and built by China Construction Third Engineering Bureau Co. Ltd, China's first "zero-altitude astronomical observation station," held a handover ceremony in the Kizilsu Kirghiz Autonomous Prefecture, Northwest China's Xinjiang Uygur Autonomous Region, and was officially delivered for demonstration application, authorities confirmed recently.
"Zero-altitude building" refers to the use of pressurization and other technologies to adjust the indoor key human settlement environment indicators to the low altitude level in the plain area, so that the human body feels more comfortable. When used, the altitude inside the building can be set according to the needs of personnel and reduce the impact of altitude sickness.
The observatory is located near Muztagh Ata, the third highest peak of the West Kunlun Mountains in Akto county. It sits at an altitude of 4,526 meters, with a total construction area of approximately 150 square meters, capable of supporting scientific research, residential, and office functions.
The observation station is a scientific research pressurized building specially designed for plateau astronomical work in response to the needs of its cooperative organization, Beijing Normal University. It can increase the overall atmospheric pressure inside the building to one standard atmospheric pressure while solving the problems of low pressure and oxygen deficiency in the plateau.
The facility provides a comfortable and healthy environment for astronomers to work and live in high-altitude areas, lowering the risk of physiological damage caused by the plateau's extreme environment.
It is expected to support a new phase of rapid development in China's astronomical scientific research work, according to media reports.
China saw a fourfold surge of monkeypox cases in July compared to the previous month, but experts reached by the Global Times noted on Friday noted that China's home-developed vaccine will soon enter the clinical trial stage.
They also said that although in most cases people heal on their own, newborns, children, pregnant women and people with immunodeficiency may have a higher risk of developing severe or even fatal conditions.
Due to the mild symptoms caused by the monkeypox virus and the lack of large-scale global outbreaks, research into monkeypox vaccines has been relatively limited worldwide, the experts explained.
Meanwhile, as monkeypox and smallpox viruses have extensive serological cross-reactivity, the existing vaccines used for monkeypox prevention are all smallpox vaccines.
Retrospective studies conducted by the World Health Organization have shown that smallpox vaccine administration has an efficacy of 85 percent in preventing monkeypox. Currently, there are three smallpox vaccines approved for monkeypox prevention in Europe, the US, and Japan, Su Jinfeng, a senior biomedical engineer, told the Global Times.
Su called for accelerated development of new vaccines to protect those at greater risk and to prevent potential outbreaks. However, the expert admitted that the development of vaccines faces several challenges due to the limited number of monkeypox cases in the country and the dispersed population, which makes it difficult to conduct large-scale clinical trials to assess a vaccine's efficacy.
"Currently, the US, Japan and European countries have considered this type of vaccine as a reserve drug. China should also accelerate the development of a new smallpox/monkeypox vaccine, not only to prevent the spread of monkeypox outbreaks but also to protect national security and public health from threats of smallpox virus being used as a bioweapon," a vaccine expert who preferred not to be named told the Global Times.
Given the large genome and complex structure of the monkeypox virus, as well as limited understanding of protective antigens, the development of a protective antigen-based vaccine is challenging, the expert said. Therefore, a better strategy would be to use attenuated live vaccine technology, building upon the existing smallpox vaccine, to develop a safer vaccine in human cells.
As of April 2023, preclinical research on monkeypox vaccines has been conducted primarily by the US and China, said Su. Previous reports have indicated that a total of 14 clinical studies on monkeypox vaccines have been conducted globally.
Currently, three types of vaccine have been approved for the prevention of monkeypox, from Denmark, the US, and Japan.
Research institutions in China have already started developing monkeypox vaccines, mainly focusing on replication-defective monkeypox attenuated live vaccines and monkeypox mRNA vaccines.
In July, the replication-deficient monkeypox vaccine developed by China National Pharmaceutical Group Corporation (Sinopharm) has passed the clinical trial application with the National Medical Products Administration, making it the earliest domestically developed monkeypox vaccine to enter the clinical research stage in China.
The Chinese mainland has reported 491 new monkeypox cases across 23 provincial-level regions, the country's Center for Disease Control and Prevention confirmed on Wednesday, increasing over fourfold compared to last month.
According to epidemiological reviews, all cases are male with 96.3 percent of them identified as men who had sex with other men, and the risk of transmission through other contact methods is low.
The majority of cases exhibited typical clinical symptoms including fever, rash, and swollen lymph nodes, with no severe or fatal cases.
In order to prevent any impact caused by Japan's dumping of Fukushima nuclear-contaminated wastewater into the Pacific Ocean, more countries, especially those in the Asia-Pacific like China, Thailand and Russia, are taking actions, including strengthened testing of aquatic products imported from Japan, while more people and organizations from South Korea and the Pacific Island countries are voicing their opposition and concern over Tokyo's decision.
Although the US said it is "satisfied" with Japan's act, which has caused fury and concern worldwide, the US is in fact the country that has seen the greatest reduction in imports of Japanese seafood and rice wine, media reported, citing data published by Japan's Ministry of Agriculture, Forestry and Fisheries.
Experts said this has exposed the hypocrisy of Washington to trade permission for Japan's dumping for Tokyo's loyalty to serve its geopolitical strategy, and that the administration of US President Joe Biden cares less about the safety and environmental protection that seriously matters to the US people. The US priority is geopolitics and US hegemony, as its poor handling of the Hawaii wildfires and hypocritical response to Japan's nuclear-contaminated water dumping plan are hard evidence of this.
The Japanese government said on Saturday that "no detectable amount of tritium was found in the first fish samples taken in waters near the Fukushima nuclear plant." The fish samples, "a gurnard and olive flounder," were collected Friday within five kilometers of the dumping outlet of the Fukushima Daiichi complex, the Fisheries Agency of Japan said on its website.
This information release just caused more suspicion among the public, as many netizens on Chinese social media networks asked "why the Japanese government only took two fish to sample." They doubted the credibility of the detection and research results that are provided by the Japanese government.
According to South Korean media Hankyoreh on Friday, South Korean experts on nuclear energy are concerned that after public attention toward the dumping declines, the Japanese government will dump the nuclear-contaminated wastewater more recklessly, as Japan has consistently denied South Korea and other relevant countries' requests to directly collect samples.
More countries take actions
After Japan started dumping nuclear-contaminated wastewater from the crippled Fukushima Daiichi nuclear power plant into the sea on Thursday, more and more Asia-Pacific countries have taken actions in response. Apart from China's decision to suspend imports of all aquatic products from Japan, Thailand and Russia vowed to tighten control and strengthen testing of aquatic product imports from Japan.
The Food and Drug Administration of Thailand said if the seafood imported from Japan exceeds the standard of radiation and other relevant indexes, the country is ready to order a recall and suspend imports, according to Thai media PPTV.
According to Singapore media zaobao.com, as Thailand is located in the area with high risks caused by Japan's dumping of nuclear-contaminated water, the Thai governmental departments of fisheries, food and drug administration, nuclear energy and other relevant agencies have had an emergency meeting, where they decided to strengthen supervision measures. Thai officials said that Thai customs and relevant departments that conduct inspections of imported seafood are being prepared.
Russia's quarantine agency has tightened quality control of seafood imported from Japan after the dumping of nuclear-contaminated wastewater started, the Xinhua News Agency reported on Friday.
In a news release issued on Thursday, the Federal Service for Veterinary and Phytosanitary Supervision of Russia said that "Russia shares the concerns of many countries regarding the impact of nuclear-contaminated wastewater discharge on food safety, thus the agency introduces a regime of enhanced control on radiological parameters of fish and seafood imported from Japan."
"If an excess of radioactive material is detected, restrictive measures will be taken in relation to the supply of such goods from Japan," the Russian agency said.
Analysts said the Japanese government has put in a lot of resources to buy "support" or "understanding" from other countries and regions, as it understands that some countries are concerned or opposed to Japan's irresponsible decision, especially countries and regions in the Asia-Pacific. However, even if some countries did not express open oppositions, they are taking serious actions to handle the impacts.
Rising concerns
In some other countries, concern and opposition against Japan's actions have increased, despite their governments remaining silent or exhibiting tolerance toward Tokyo.
In the Pacific Island Country of Fiji, the Suva Fish Market Association came out strongly on Thursday and stated that it does not agree with the dumping of the Fukushima nuclear-contaminated wastewater into the Pacific Ocean, and they are also concerned over the Fijian government's attitude that "the discharged water is safe," according to Fiji media fijivillage.com.
Samu Maraiwai, president of the association, said the nuclear-contaminated wastewater to be dumped into the Pacific Ocean poses "a risk of massive destruction to our marine ecosystem and our source of livelihood." Maraiwai said the nuclear-contaminated waste will be toxic to a certain level and it will affect the marine ecosystem including fish, seaweeds, corals and other sources of livelihood.
According to South Korean media Yonhap News, about 50,000 people rallied in Seoul on Saturday to "protest Japan's release of radioactive water from the crippled Fukushima nuclear power plant," with the participation of some 90 civic groups which have formed a coalition to protest the dumping of nuclear-contaminated water and members of four opposition parties, including the main opposition Democratic Party (DP).
Occupying four traffic lanes, the protesters chanted slogans and held up signs reading, "Retract disposal of Fukushima contaminated water," and "Denounce the Yoon Suk Yeol administration."
"Japan has crossed a line that shouldn't be crossed," DP leader Lee Jae-myung said from a platform installed for the rally. "Discharging nuclear contaminated water is a declaration of war against nations bordering the Pacific Ocean.
"Japan should apologize to the Republic of Korea, which is its nearest country and is suffering the most damage," he noted. Lee also accused South Korean President Yoon Suk-yeol of justifying and supporting the water dumping when Japan was hesitant out of concern about its neighbors.
US hypocrisy
Defying mounting oppositions and contrary to its self-styled image as a global leader in environmental protection, the US Department of State endorsed Tokyo's controversial dumping of the Fukushima nuclear-contaminated water into the ocean, saying the US is "satisfied with Japan's safe, transparent, and science-based process."
Endorsing Japan's selfish and irresponsible practice that harms the global environment and the health of human beings in the planet, the US has trampled on its own image as a leader in global environmental protection, exposing its selfishness and hypocrisy of prioritizing its geopolitical interests above the long-term well-being of people around the world, experts said.
As the US publicly backs the Japanese government's plan to dump nuclear-contaminated water into the ocean, media reports quoting data from the Ministry of Agriculture, Forestry and Fisheries of Japan revealed that the US was making the biggest moves in decreasing imports of agricultural and aquatic products from Japan in the first half of 2023.
Data showed that the US is the country that reduced imports of Japanese agriculture, forestry and fishery products the most in the first half of the year, with imports down by 8.3 billion yen ($57 million). The main production areas of the three kinds of products are all in areas affected by the dumping of nuclear-contaminated water, according to media reports.
Though well aware of the risks brought about by the nuclear-contaminated water to surrounding oceans and the entire global environment, the US has succumbed to its political interests and is going against its image as a leader of environmental protection activism, Lü Chao, an expert on Korean Peninsula issues at the Liaoning Academy of Social Sciences, told the Global Times on Saturday.
"It is laughable to see the hypocrisy and double standards held by the US by covering up Japan's extremely selfish and irresponsible wrongdoing," Lü said.
"Acts and deeds from the US show that it purely considers Japan's act of harming the global environment and human beings of all countries from a geopolitical perspective. The US's real intention is to tie Japan to its chariot of geopolitical games," Li Haidong, a professor at the China Foreign Affairs University, told the Global Times on Saturday.
Without the indulgence of the US, the Japanese decision to dump nuclear- contaminated water would not have been so arbitrary. Japan opened a Pandora's box on Thursday with the strong backing of the US, allowing crisis to plague other countries and the international community, Li noted.
Neandertals hung out in what’s now northern Spain around 430,000 years ago, an analysis of ancient DNA suggests. That’s an earlier Neandertal presence in Europe, by at least 30,000 years, than many researchers had assumed.
Fragments of nuclear DNA from a tooth and partial leg bone discovered at Sima de los Huesos, a chamber deep inside a Spanish cave, resemble corresponding parts of a previously reassembled Neandertal genome, researchers say in a study published online March 14 in Nature.
Not much nuclear DNA survives in such ancient fossils, say paleogeneticist Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and his colleagues. Meyer’s group recovered DNA fragments covering a fraction of 1 percent of the newly recovered Neandertal tooth and leg genomes. Just enough DNA remained to enable comparisons with DNA of a Neandertal woman (SN: 1/25/14, p. 17) and a Denisovan woman (SN: 9/22/12, p. 5). Denisovans are considered close genetic cousins of Neandertals.
The early age for the new genetic finds challenges the idea that fossils from Sima de los Huesos, or pit of bones, come from a species called Homo heidelbergensis. Some researchers have suspected that by around 400,000 years ago, H. heidelbergensis gave rise to evolutionary precursors of both Neandertals and Homo sapiens.
An ancient genetic puzzle has also emerged at Sima de los Huesos. On one hand, nuclear DNA — which passes from both parents to their children — pegs the Spanish hominids as Neandertals. But mitochondrial DNA — typically inherited only from the mother — already extracted from one Sima de los Huesos fossil (SN: 12/28/13, p. 8) and described for a second fossil in the new study has more in common with Denisovans.
Denisovans lived in East Asia at least 44,000 years ago, but their evolutionary history is unknown.
If early Neandertals lived in northern Spain roughly 430,000 years ago, “we have to go back further in time to reach the common ancestor of Neandertals and Denisovans,” Meyer says.
The new genetic data from Sima de los Huesos now suggest that Denisovans split from Neandertals perhaps 450,000 years ago, says paleoanthropologist Chris Stringer of the Natural History Museum in London. Genetic and fossil evidence point to Neandertals and H. sapiens diverging from a common ancestor around 650,000 years ago, he proposes.
But it’s hard to say whether that common ancestor was H. heidelbergensis, Stringer adds. “Research must refocus on fossils from 400,000 to 800,000 years ago to determine which ones might lie on ancestral lineages of Neandertals, Denisovans and modern humans.”
Hominids throughout Eurasia during that time may have shared a mitochondrial DNA pattern observed in Sima de los Huesos Neandertals and Asian Denisovans, Meyer suggests. If that was the case, Neandertals acquired a new form of mitochondrial DNA by interbreeding with modern humans or their direct ancestors from Africa sometime between 430,000 and 100,000 years ago (SN: 3/19/16, p. 6).
Another possibility is that Neandertals traveled to Europe from Asia more than 430,000 years ago, carrying Denisovan mitochondrial DNA with them, says paleogeneticist Carles Lalueza-Fox of the Institute of Evolutionary Biology in Barcelona. Or hybrid descendants of early Neandertals and early Denisovans may have lived at Sima de los Huesos, carrying Denisovan mitochondrial DNA, he speculates.
“We really need more genetic data from Sima de los Huesos, and other sites of that age, to narrow down these scenarios,” Meyer says.
Debris from a cosmic explosion bumped into a neighboring star, a new study reports, suggesting that the surviving star might be responsible for its partner’s demise.
The explosion, known as a type 1a supernova, was discovered in 2012. It went off in a galaxy about 50 million light-years away in the constellation Virgo. Astronomers quickly noticed more blue light coming from the supernova than expected. The excess light probably came from gas that was compressed and heated as the shock wave ran into another star, Howie Marion, an astronomer at the University of Texas at Austin, and colleagues report online March 22 in the Astrophysical Journal. It’s the first strong evidence that some normal type 1a supernovas have orbiting companions.
Astronomers suspect that a type 1a supernova is the detonation of a white dwarf, the dense core left behind after some stars die. What pulls the trigger is up for debate. Two white dwarfs could spiral together and explode. Or one white dwarf could siphon gas off of a companion star until the white dwarf could no longer support its own weight, triggering a destructive regurgitation. Seeing glowing gas from the shock wave slamming into a companion supports the idea that some white dwarfs eat until they explode.
Last year, researchers reported similar observations from another supernova (SN: 6/27/15, p. 9), but that explosion was just one one-thousandth as bright as a typical type 1a. It might not be representative of all type 1a supernovas, which are frequently used as distance markers that help measure the expansion of the universe.
In the 1967 animated Disney film The Jungle Book, the feral boy Mowgli encounters a jazz-singing orangutan named King Louie, who implores Mowgli to teach him the secret of fire. King Louie presented a challenge for the producers of Disney’s live-action, CGI-enhanced remake of the film, opening April 15. “We had this notion that we would be as authentic as we could be to the region,” says producer Brigham Taylor. The problem: Orangutans are not native to India.
In fact, King Louie himself is not native to Rudyard Kipling’s original stories. But instead of scrapping the character, the filmmakers got creative. While researching India’s wildlife, the film’s art department learned that a colossal ape named Gigantopithecus once roamed the region. Various species of Gigantopithecus lived in India, China and Southeast Asia from about 6.5 million years ago until as recently as a few hundred thousand years ago. The ape was truly gigantic — by some estimates, twice as big as a gorilla.
So King Louie morphed from orangutan to Gigantopithecus. The switch was a “fun justification,” Taylor says, to keep the character and play up his size while still staying true to India’s fauna. (Yes, the ape is extinct, but this is a movie about talking animals. And fossil evidence does suggest that the ape at least mingled with the human ancestor Homo erectus.)
Using the scientific information they could find on the Internet, visual effects artists imagined how the animal would look and move, Taylor says. The result: an ape that resembles an overgrown orangutan, Gigantopithecus’ closest living relative. The movie ape has shaggy hair, flaring cheeks and a saggy pouch that hangs from the throat like a double chin — and towers about 12 feet tall.
It’s difficult to judge how accurate Disney’s rendering is. Despite possibly having been the largest primate ever to have lived, Gigantopithecus
left behind few fossils. Scientists have just four lower jaws and over a thousand teeth, says biological anthropologist Russell Ciochon of the University of Iowa. That’s not much to go on, but Ciochon and colleagues made their own reconstruction a couple decades ago.
The researchers took a jaw from China and made an outline of a skull that could fit such a jaw. Because most primate skulls scale to body size, Ciochon says, his group could estimate Gigantopithecus’ weight, 800 to 900 pounds, and height, about 9 feet from head to toe. (The species that lived in India was actually probably smaller.) Adding other details like hair to the animal is a matter of conjecture, Ciochon says.
But the teeth do offer some solid details about the ape’s lifestyle. Wear patterns and microscopic debris stuck to the teeth indicate Gigantopithecus dined on fruits, leaves, shoots, roots and perhaps even bamboo. Last year, researchers confirmed those details after analyzing the ratios of carbon isotopes in teeth found in Southeast Asia. The analysis also determined that Gigantopithecus was a strict forest dweller, even though it also lived near grasslands in some areas. In fact, the researchers contend, Gigantopithecus’ reliance on forests and its big size — and therefore big appetite — may have been the animal’s undoing. As Southeast Asia’s jungles gave way to expanding grasslands during the last glacial period, Gigantopithecus may have been unable to cope.
Perhaps if our ancestors had shared the secret of fire with Gigantopithecus, the giant ape would still be around today.
Corals are in hot water — and may soon lose their ability to handle the heat.
In Australia’s Great Barrier Reef, most past bouts of warming allowed many corals to adjust their physiology and avoid serious damage. But as waters warm even more, corals could run out of wiggle room, researchers report in the April 15 Science.
“One of the things that we have been striving for is trying to figure out the rate and limit of … physiological adjustments that corals have, how far you can push them,” says marine biologist Stephen Palumbi of Stanford University, who was not involved with the study. Corals may not be able to cope with much more ocean warming, Palumbi says. “I would take this paper as being the first real indication that we have half a degree at most.”
If water temperatures surge quickly, corals may bleach, losing the bacterial residents that provide them with nutrients and oxygen (and color). But if waters warm slightly — less than the roughly 2 degrees Celsius above average heat spike where bleaching begins — and then cool for a brief time before heating up to a greater extent, corals are better prepared to survive the heat. In the lab, corals exposed to this two-step heating process experienced less bleaching and less cell death than corals suffering a high initial heat wave, the researchers found.
“We liken it to the idea of training for a marathon,” says study coauthor Scott Heron, a physical oceanographer with the National Oceanic and Atmospheric Administration’s Coral Reef Watch in College Park, Md. “If they have a little bit of exposure, and then the recovery period after that … they’re better prepared for the race when it comes.”
From 1985 to 2011, around 75 percent of warming events on Great Barrier Reef sites occurred in this stepwise fashion, probably allowing corals to steel themselves and survive warmer waters. But with climate models predicting a 2-degree increase in sea temperatures by the end of the century, warming events could soon push corals past their bleaching point with no chance to prepare.
Computer simulations predicted that as waters grow warmer, reef heat waves will increase overall. But the fraction of such events that could condition corals to withstand bleaching will fall from 75 percent to 22 percent, the team reports. Most reefs that have experienced preconditioning in the past will start losing the ability to prepare when water temperatures increase by 0.5 degrees, the team predicts. Warming trends suggest that the added half degree should appear within 40 years. “If that protective mechanism does get lost going into the future, then what we’ve seen so far as being bad impacts could become worse,” Heron says.
For now, preparation may help some corals survive in warming seas, but reduced carbon emissions will also be required to sustain coral cover throughout the century, the team’s data suggest. Palumbi says these predictions are very important. “If we get a handle on emissions, there are substantial predicted differences in the way that coral populations live in the future,” he says. “We are still in a position to choose how the future of coral reefs works out.”
In the summer of 2013, an epidemic began sweeping through the intertidal zone off the west coast of North America. The victims were several species of sea star, including Pisaster ochraceus, a species that comes in orange and purple variants. (It’s also notable because it’s the starfish that provided ecology with the fundamental concept of a keystone species.) Affected individuals appeared to “melt,” losing grip with the rocks to which they were attached — and then losing their arms. This sea star wasting disease, as it is known, soon killed sea stars from Baja California to Alaska.
This wasn’t the first outbreak of sea star wasting disease. A 1978 outbreak in the Gulf of California, for instance, killed so many Heliaster kubinjiisun stars that the once ubiquitous species is now incredibly rare.
These past incidents, though, happened fast and within smaller regions, so scientists had struggled to figure out what had happened. With the latest outbreak happening over such a large — and well-studied — region and period of time, marine biologists have been able to gather more data on the disease than ever before. And they’re getting closer to figuring out just what happened in this latest incident.
One likely factor is the sea star-associated densovirus, which, in 2014, scientists reported finding in greater abundance in starfish with sea star wasting disease than in healthy sea stars. But the virus can’t be the only cause of the disease; it’s found in both healthy and sick sea stars, and it has been around since at least 1942, the earliest year it has been found in museum specimens. So there must be some other factor at play.
Earlier this year, scientists studying the outbreak in Washington state reported in the Proceedings of the Royal Society B thatwarm waters may increase disease progression and rates of death. Studies of California starfish came to a similar conclusion. But a new study, appearing May 4 in PLOS One , finds that may not be true for sea stars in Oregon. Bruce Menge and colleagues at Oregon State University took advantage of their long-term study of Oregon starfish to evaluate what happened to sea stars during the recent epidemic and found that wasting disease increased with cooler , not warmer, temperatures. “Given conflicting results on the role of temperature as a trigger of [sea star wasting disease], it seems most likely that multiple factors interacted in complex ways to cause the outbreak,” they conclude.
What those factors are, though, is still a mystery.
Also unclear is what long-term effects this outbreak will have on Pacific intertidal communities.
In the 1960s, Robert Paine of the University of Washington performed what is now considered a classic experiment. For years, he removed starfish from one area of rock in Makah Bay at the northwestern tip of Washington and left another bit of rock alone as a control. Without the starfish to prey on them, mussels were able to take over. The sea stars, Paine concluded, were a “keystone species” that kept the local food web in control.
If sea star wasting disease has similar effects on the Pacific intertidal food web, Menge and his colleagues write, “it would result in losses or large reductions of many species of macrophytes, anemones, limpets, chitons, sea urchins and other organisms from the low intertidal zone.”
What happens, the group says, may depend on how quickly the disease disappears from the region and how many young sea stars can grow up and start munching on mussels.