Lung Diseases on the Rise Worldwide

THURSDAY, Feb. 20, 2020 (HealthDay News) -- Lung diseases have been striking more people around the world in the past 30 years, new research shows.

And being from poor regions is the most important risk factor for respiratory trouble, the scientists added.

Aging and risk factors such as smoking, pollution and overweight/obesity are among the other major risk factors for chronic lung diseases, according to the analysis of data from 195 countries.

Researchers led by Dr. Min Xie, from Tongji Medical College and Huazhong University of Science and Technology in Wuhan, China, found that the number of deaths from chronic lung diseases rose 18% over the past three decades, from 3.3 million in 1990 to 3.9 million in 2017.

The number of deaths increased with age and rose sharply among people aged 70 and older, and this age-related burden is likely to increase as the worldwide population ages, the researchers noted.

The most common chronic lung diseases are chronic obstructive pulmonary disease (COPD) and asthma, but others such as pneumoconiosis (lung disease due to dust inhalation), interstitial lung disease and pulmonary sarcoidosis (due to lung scarring and inflammation) are also public health concerns worldwide.

The study was published Feb. 19 in the BMJ journal.

Overall, the highest rates of lung disease are in the poorest regions of the world. Lower rates in wealthier countries are due to people having better access to health services and improved treatments, Xie and colleagues said.

Smoking is the leading risk factor for deaths and disability due to COPD and asthma. In 2017, smoking accounted for 1.4 million deaths.

The impact of smoking was particularly strong in poorer areas, which shows the urgent need to improve tobacco control in developing countries, the study authors said.

Pollution from airborne particulate matter was the next most important risk factor for COPD.

Obesity accounted for the most deaths from asthma since 2013, particularly in women.

"As the prevalence of obesity continues to increase at a worrying rate worldwide, weight loss should be included in the management of obese patients with asthma," the researchers wrote in a journal news release.

More information

The American Lung Association offers health tips for your lungs.

SOURCE: BMJ, news release, Feb. 19, 2020

Facial expressions don't tell the whole story of emotion

Interacting with other people is almost always a game of reading cues and volleying back. We think a smile conveys happiness, so we offer a smile in return. We think a frown shows sadness, and maybe we attempt to cheer that person up.

Some businesses are even working on technology to determine customer satisfaction through facial expressions.

But facial expressions might not be reliable indicators of emotion, research indicates. In fact, it might be more accurate to say we should never trust a person's face, new research suggests.

"The question we really asked is: 'Can we truly detect emotion from facial articulations?'" said Aleix Martinez, a professor of electrical and computer engineering at The Ohio State University.

"And the basic conclusion is, no, you can't."

Martinez, whose work has focused on building computer algorithms that analyze facial expressions, and his colleagues presented their findings today (Feb. 16, 2020) at the annual meeting of the American Association for the Advancement of Science in Seattle.

The researchers analyzed the kinetics of muscle movement in the human face and compared those muscle movements with a person's emotions. They found that attempts to detect or define emotions based on a person's facial expressions were almost always wrong.

"Everyone makes different facial expressions based on context and cultural background," Martinez said. "And it's important to realize that not everyone who smiles is happy. Not everyone who is happy smiles. I would even go to the extreme of saying most people who do not smile are not necessarily unhappy. And if you are happy for a whole day, you don't go walking down the street with a smile on your face. You're just happy."

It is also true, Martinez said, that sometimes, people smile out of an obligation to the social norms. This would not inherently be a problem, he said -- people are certainly entitled to put on a smile for the rest of the world -- but some companies have begun developing technology to recognize facial muscle movements and assign emotion or intent to those movements.

The research group that presented at AAAS analyzed some of those technologies and, Martinez said, largely found them lacking.

"Some claim they can detect whether someone is guilty of a crime or not, or whether a student is paying attention in class, or whether a customer is satisfied after a purchase," he said. "What our research showed is that those claims are complete baloney. There's no way you can determine those things. And worse, it can be dangerous."

The danger, Martinez said, lies in the possibility of missing the real emotion or intent in another person, and then making decisions about that person's future or abilities.

For example, consider a classroom environment, and a teacher who assumes that a student is not paying attention because of the expression on the student's face. The teacher might expect the student to smile and nod along if the student is paying attention. But maybe that student, for reasons the teacher doesn't understand -- cultural reasons, perhaps, or contextual ones -- is listening intently, but not smiling at all. It would be, Martinez argues, wrong for the teacher to dismiss that student because of the student's facial expressions.

After analyzing data about facial expressions and emotion, the research team -- which included scientists from Northeastern University, the California Institute of Technology and the University of Wisconsin -- concluded that it takes more than expressions to correctly detect emotion.

Facial color, for example, can help provide clues.

"What we showed is that when you experience emotion, your brain releases peptides -- mostly hormones -- that change the blood flow and blood composition, and because the face is inundated with these peptides, it changes color," Martinez said.

The human body offers other hints, too, he said: body posture, for example. And context plays a crucial role as well.

In one experiment, Martinez showed study participants a picture cropped to display just a man's face. The man's mouth is open in an apparent scream; his face is bright red.

"When people looked at it, they would think, wow, this guy is super annoyed, or really mad at something, that he's angry and shouting," Martinez said. "But when participants saw the whole image, they saw that it was a soccer player who was celebrating a goal."

In context, it's clear the man is very happy. But isolate his face, Martinez said, and he appears almost dangerous.

Cultural biases play a role, too.

"In the U.S., we tend to smile a lot," Martinez said. "We are just being friendly. But in other cultures, that means different things -- in some cultures, if you walked around the supermarket smiling at everyone, you might get smacked."

Martinez said the research group's findings could indicate that people -- from hiring managers to professors to criminal justice experts -- should consider more than just a facial expression when they evaluate another person.

And while Martinez said he is "a big believer" in developing computer algorithms that try to understand social cues and the intent of a person, he added that two things are important to know about that technology.

"One is you are never going to get 100 percent accuracy," he said. "And the second is that deciphering a person's intent goes beyond their facial expression, and it's important that people -- and the computer algorithms they create -- understand that."

Critical Coronavirus Breakthrough Seeks Blood from Recovered Patients

  • Wuhan reportedly has cured patients with coronavirus by injecting plasma from recovered individuals.
  • The breakthrough could help minimize the outbreak in key areas like Hubei.
  • President Xi Jinping said China is seeing progress in combating the outbreak.

Wuhan is said to have treated individuals in critical condition affected by coronavirus by injecting blood plasma from patients that have recovered from the virus.

First big milestone in containing coronavirus in China

Dovey Wan, founding partner at Primitive Crypto, shared a brochure from local hospitals in Wuhan asking for blood donations from individuals that fully recovered from coronavirus.

She said: "This is a major milestone if true. Various Wuhan hospitals have treated people in critical condition successfully by injecting plasma from who have recovered from coronavirus with neutralizing antibodies. Now they are calling for blood donation from recovered ones in all outlets."

Last month, China’s top virologist Yi Guan said that the golden window of containment for coronavirus was missed.

Consequently, the virus outbreak expanded rapidly throughout the entire Hubei region, placing nearly 60 million in lockdown or household quarantine.

Already having missed the chance to contain the virus outbreak to a minimum, it is crucial for the government of China to find ways to treat as many individuals that have coronavirus as fast as possible while vaccines get produced.

Early estimates across various regions including Hong Kong show that it will take a full year before vaccines for coronavirus can be distributed for actual use.

Hence, if Wuhan and the Hubei region can begin to treat many patients that have coronavirus with local resources, it would play a vital role in lessening the outbreak until vaccines are distributed across China.

China hastens to minimize the outbreak

The Chinese economy faces a steep decline if the coronavirus outbreak fails to be controlled in the upcoming months.

Millions of people in Hubei are unable to work and the drop in the workforce will negatively affect the growth of the Chinese economy which President Xi Jinping has placed an emphasis on in the past several years.

Local publications have reported that President Xi is already beginning to urge local governments to Work towards meeting development objectives.

President Xi firmly noted that the coronavirus outbreak should not put an end to the plans of the government to continue the expansion of China’s economy.

Up until last week, the focus of President Xi’s message was on the containment of the virus. President Xi’s recent address indicates China sees significant progress in treating coronavirus, and breakthroughs like the treatment of individuals in Wuhan can fasten the process of minimizing the outbreak.

First childhood flu helps explain why virus hits some people harder than others

Why are some people better able to fight off the flu than others? Part of the answer, according to a new study, is related to the first flu strain we encounter in childhood.

Scientists from UCLA and the University of Arizona have found that people's ability to fight off the flu virus is determined not only by the subtypes of flu they have had throughout their lives, but also by the sequence in which they are been infected by the viruses. Their study is published in the open-access journal PLoS Pathogens.

The research offers an explanation for why some people fare much worse than others when infected with the same strain of the flu virus, and the findings could help inform strategies for minimizing the effects of the seasonal flu.

In addition, UCLA scientists, including Professor James Lloyd-Smith, who also was a senior author of the PLoS Pathogens research, recently completed a study that analyzes travel-related screening for the new novel coronavirus 2019-nCoV.

The researchers report that screening travelers is not very effective for the 2019 coronavirus -- that it will catch less than half of infected travelers, on average -- and that most infected travelers are undetectable, meaning that they have no symptoms yet, and are unaware that they have been exposed. So stopping the spread of the virus is not a matter of just enhancing screening methods at airports and other travel hubs.

"This puts the onus on government officials and public health officials to follow up with travelers after they arrive, to isolate them and trace their contacts if they get sick later," said Lloyd-Smith, a UCLA professor of ecology and evolutionary biology. Many governments have started to impose quarantines, or even travel bans, as they realize that screening is not sufficient to stop the spread of the coronavirus.

One major concern, Lloyd-Smith said, is that other countries, especially developing nations, lack the infrastructure and resources for those measures, and are therefore vulnerable to importing the disease.

"Much of the public health world is very concerned about the virus being introduced into Africa or India, where large populations exist do not have access to advanced medical care," he said.

The researchers, including scientists from the University of Chicago and the London School of Tropical Hygiene and Medicine, have developed a free online app where people can calculate the effectiveness of travel screening based on a range of parameters.

Solving a decades-old question

The PLoS Pathogens study may help solve a problem that had for decades vexed scientists and health care professionals: why the same strain of the flu virus affects people with various degrees of severity.

A team that included some of the same UCLA and Arizona scientists reported in 2016 that exposure to influenza viruses during childhood gives people partial protection for the rest of their lives against distantly related influenza viruses. Biologists call the idea that past exposure to the flu virus determines a person's future response to infections "immunological imprinting."

The 2016 research helped overturn a commonly held belief that previous exposure to a flu virus conferred little or no immunological protection against strains that can jump from animals into humans, such as those causing the strains known as swine flu or bird flu. Those strains, which have caused hundreds of spillover cases of severe illness and death in humans, are of global concern because they could gain mutations that allow them to readily jump not only from animal populations to humans, but also to spread rapidly from person to person.

In the new study, the researchers investigated whether immunological imprinting could explain people's response to flu strains already circulating in the human population and to what extent it could account for observed discrepancies in how severely the seasonal flu affects people in different age groups.

To track how different strains of the flu virus affect people at different ages, the team analyzed health records that the Arizona Department of Health Services obtains from hospitals and private physicians.

Two subtypes of influenza virus, H3N2 and H1N1, have been responsible for seasonal outbreaks of the flu over the past several decades. H3N2 causes the majority of severe cases in high-risk elderly people and the majority of deaths from the flu. H1N1 is more likely to affect young and middle-aged adults, and causes fewer deaths.

The health record data revealed a pattern: People first exposed to the less severe strain, H1N1, during childhood were less likely to end up hospitalized if they encountered H1N1 again later in life than people who were first exposed to H3N2. And people first exposed to H3N2 received extra protection against H3N2 later in life.

The researchers also analyzed the evolutionary relationships between the flu strains. H1N1 and H3N2, they learned, belong to two separate branches on the influenza "family tree," said James Lloyd-Smith, a UCLA professor of ecology and evolutionary biology and one of the study's senior authors. While infection with one does result in the immune system being better prepared to fight a future infection from the other, protection against future infections is much stronger when one is exposed to strains from the same group one has battled before, he said.

The records also revealed another pattern: People whose first childhood exposure was to H2N2, a close cousin of H1N1, did not have a protective advantage when they later encountered H1N1. That phenomenon was much more difficult to explain, because the two subtypes are in the same group, and the researchers' earlier work showed that exposure to one can, in some cases, grant considerable protection against the other.

"Our immune system often struggles to recognize and defend against closely related strains of seasonal flu, even though these are essentially the genetic sisters and brothers of strains that circulated just a few years ago," said lead author Katelyn Gostic, who was a UCLA doctoral student in Lloyd-Smith's laboratory when the study was conducted and is now a postdoctoral fellow at the University of Chicago. "This is perplexing because our research on bird flu shows that deep in our immune memory, we have some ability to recognize and defend against the distantly related, genetic third cousins of the strains we saw as children.

"We hope that by studying differences in immunity against bird flus -- where our immune system shows a natural ability to deploy broadly effective protection -- and against seasonal flus -- where our immune system seems to have bigger blind spots -- we can uncover clues useful to universal influenza vaccine development."

Around the world, influenza remains a major killer. The past two flu seasons have been more severe than expected, said Michael Worobey, a co-author of the study and head of the University of Arizona's department of ecology and evolutionary biology. In the 2017-18 season, 80,000 people died in the U.S., more than in the swine flu pandemic of 2009, he said.

People who had their first bout of flu as children in 1955 -- when the H1N1 was circulating but the H3N2 virus was not -- were much more likely to be hospitalized with an H3N2 infection than an H1N1 infection last year, when both strains were circulating, Worobey said.

"The second subtype you're exposed to is not able to create an immune response that is as protective and durable as the first," he said.

The researchers hope that their findings could help predict which age groups might be severely affected during future flu seasons based on the subtype circulating. That information could also help health officials prepare their response, including decisions about who should receive certain vaccines that are only available in limited quantities.

The research was funded by the National Institutes of Health, the National Science Foundation, DARPA and the David and Lucile Packard Foundation. In 2018, the NIH's National Institute of Allergy and Infectious Diseases announced a strategic plan to develop a universal flu vaccine.

The study's co-authors are Rebecca Bridge of the Arizona Department of Health Services and Cecile Viboud of the Fogarty International Center at the NIH.


Story Source:

Materials provided by University of California - Los Angeles. Original written by Stuart Wolpert and Daniel Stolte. Note: Content may be edited for style and length.


Eating red meat and processed meat hikes heart disease and death risk, study finds

After a controversial study last fall recommending that it was not necessary for people to change their diet in terms of red meat and processed meat, a large, carefully analyzed new study links red and processed meat consumption with slightly higher risk of heart disease and death, according to a new study from Northwestern Medicine and Cornell University.

Eating two servings of red meat, processed meat or poultry -- but not fish -- per week was linked to a 3 to 7% higher risk of cardiovascular disease, the study found. Eating two servings of red meat or processed meat -- but not poultry or fish -- per week was associated with a 3% higher risk of all causes of death.

"It's a small difference, but it's worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats," said senior study author Norrina Allen, associate professor of preventive medicine at Northwestern University Feinberg School of Medicine. "Red meat consumption also is consistently linked to other health problems like cancer."

"Modifying intake of these animal protein foods may be an important strategy to help reduce the risk of cardiovascular disease and premature death at a population level," said lead study author Victor Zhong, assistant professor of nutritional sciences at Cornell, who did the research when he was a postdoctoral fellow in Allen's lab.

The paper will be published Feb. 3 in JAMA Internal Medicine.

The new findings come on the heels of a controversial meta-analysis published last November that recommended people not reduce the amount of red meat and processed meat they eat. "Everyone interpreted that it was OK to eat red meat, but I don't think that is what the science supports," Allen said.

"Our study shows the link to cardiovascular disease and mortality was robust," Zhong said.

What should we eat?

"Fish, seafood and plant-based sources of protein such as nuts and legumes, including beans and peas, are excellent alternatives to meat and are under-consumed in the U.S.," said study coauthor Linda Van Horn, professor of preventive medicine at Feinberg who also is a member of the 2020 U.S. Dietary Guidelines Advisory committee.

The study found a positive association between poultry intake and cardiovascular disease, but the evidence so far isn't sufficient to make a clear recommendation about poultry intake, Zhong said. Still, fried chicken is not recommended.

The new study pooled together a large diverse sample from six cohorts, included long follow-up data up to three decades, harmonized diet data to reduce heterogeneity, adjusted a comprehensive set of confounders and conducted multiple sensitivity analyses. The study included 29,682 participants (mean age of 53.7 years at baseline, 44.4% men and 30.7% non-white). Diet data were self-reported by participants, who were asked a long list of what they ate for the previous year or month.

Key findings:

  • A 3 to 7% higher risk of cardiovascular disease and premature death for people who ate red meat and processed meat two servings a week.
  • A 4% higher risk of cardiovascular disease for people who ate two servings per week of poultry, but the evidence so far is not sufficient to make a clear recommendation about poultry intake. And the relationship may be related to the method of cooking the chicken and consumption of the skin rather than the chicken meat itself.
  • No association between eating fish and cardiovascular disease or mortality.

Limitations of the study are participants' dietary intake was assessed once, and dietary behaviors may have changed over time. In addition, cooking methods were not considered. Fried chicken, especially deep fat-fried sources that contribute trans-fatty acids, and fried fish intake have been positively linked to chronic diseases, Zhong said.

Other Northwestern authors are Dr. Philip Greenland, Dr. Mercedes R. Carnethon, Dr. Hongyan Ning, Dr. John T. Wilkins and Dr. Donald M. Lloyd-Jones.

The study was funded by National Institutes of Health/National Heart, Lung, and Blood Institute (R21 HL085375), American Heart Association Strategically Focused Research Networks and the Feinberg School of Medicine.


Story Source:

Materials provided by Northwestern University. Original written by Marla Paul. Note: Content may be edited for style and length.


Here's The Science on How Serious The Wuhan Coronavirus Outbreak Actually Is

How serious is the coronavirus outbreak? What are its symptoms and how contagious is it? Experts studying the new virus still have key questions to answer before they can assess its danger.

The toll so far

As of Tuesday, more than 4,500 cases have been confirmed in China, its country of origin, of which 106 have been fatal. Several cases have been detected in Asian countries, as well as a few in Australia, France and the United States.

So far, no-one outside China has died, but both Germany and Japan on Tuesday confirmed cases of human-to-human transmission of the disease.

2019-nCoV, as it has been named, is part of the coronavirus virus family, the source of two previous fatal epidemics.

The 2002/03 SARS outbreak (Severe Acute Respiratory Syndrome) started in Beijing and killed 774 people out of a total 8,096 infected.

The 2012 MERS outbreak (Middle East respiratory syndrome) killed 858 people out of the 2,494 infected.

So those outbreaks had significantly different mortality rates of 9.5 percent and 34.5 percent respectively.

In general however, those hit by the new virus "are in a less serious condition than with SARS", said Yazdan Yazdanpanah, head of infectious diseases at Paris Diderot University.

"For the moment, the mortality rate is less than five percent", he added.

Symptoms

Chinese scientists reported in The Lancet Friday that, based on a study of 41 early-detected cases, some of the new virus's symptoms resemble those of SARS.

All patients had pneumonia, most had a fever, three-quarters of them were coughing and more than half had trouble breathing.

Despite this, lead author Bin Lao added: "there are some important differences", such as a lack of runny noses, sneezing or sore throats.

The average age of the 41 patients studied was 49, most of them having visited Wuhan market, identified as the source of the outbreak. Nearly a third of them had serious breathing difficulties and six of them died.

All this gives a preliminary sketch of the new virus, even if one has to be cautious about drawing conclusions based on such a small sample.

The study is all the more important because a current epidemic of flu, which has similar symptoms, has made isolating patients of the new virus difficult.

Contagion

Scientists at Britain's Imperial College estimate that each coronavirus patient infects on average 2.6 others - making it roughly as infectious as annual influenza outbreaks.

Ma Xiaowei, head of China's National Health Commission, said that transmission of coronavirus was possible during the disease's incubation period.

That means that someone who is sick with coronavirus would be able to pass it on to someone else even if they aren't yet displaying any symptoms.

This working hypothesis is yet to be fully confirmed, however.

"In my view it is premature to conclude, on the basis of the evidence currently available, that the new virus can be transmitted before symptoms appear," said Mark Woolhouse, professor of Infectious Disease Epidemiology, University of Edinburgh.

Origins

Researchers think the new virus probably came from bats, as the SARS virus did, with which it shares 80 percent of its genetic makeup.

But we still don't know which animal passed it on to humans. Last week a Chinese team suggested it could be a snake, but that was immediately challenged by other experts, who think a mammal is the more likely culprit.

Identifying which animal it was could help fight the outbreak.

With SARS, it turned out to be a civet, whose meat is very popular in China.

Banning the consumption of civet and closing their breeding farms helped stop SARS from making a comeback, says Arnaud Fontanet of the Pasteur Institute in Paris.

On the other hand, one reason it was harder to stem the MERS outbreak is because it came from dromedary camels, a widely used working animal.

Precautions

Health authorities and scientists say the same precautions against other viral illnesses can be used: wash your hands frequently, cover up your coughs, try not to touch your face.

And anyone who does come down with the virus should be placed in isolation.

"Considering that substantial numbers of patients with SARS and MERS were infected in health-care settings", precautions need to be taken to prevent that happening again, the Chinese team warned in The Lancet.

Climate Change Corrodes Shark Skin

We’ve heard it before that sharks have repeatedly survived mass extinctions… surely, they should be able to survive the one our planet seems to currently be undergoing, right? Although they have been around since the dinosaurs, it seems sharks are facing their most fearsome foe yet: climate change.

After destroying their habitats, overfishing, and hunting them, humans have caused shark numbers to decline at a staggering rate. In a study published in the journal https://www.nature.com/articles/s41598-019-54795-7">Scientific Reports, researchers show that prolonged exposure to acidified water corrodes shark’s skin. Shark skin is not like ours; it’s made up of thousands of little scales, called dermal denticles, that have a makeup like teeth. While some can be seen by the naked eye, the impact acidic water has on dermal denticles can only be seen via electron microscope. But how acidic are we talking about? Currently our oceans average a pH of 8.1, which is apparently 25 percent more acidic than in pre-industrial times. For this research, the scientists kept puffadder shysharks (Haploblepharus edwardsii) in tanks of 7.3 pH water. Why this specific number? According to one estimate, ocean water could be this acidic by the year 2300.

“It's probably not going to be an average for the ocean, even in 2300,” Luiz Rocha, curator of fishes at the California Academy of Sciences, told Wired. “Unless instead of slowing down, we continue racking up the amount of greenhouse gases that we're dumping in the atmosphere. If it drops to 7.3, we are doomed. Everything is going to fall apart, not just sharks.”

Climate change will have an enormously varied impact on the world’s oceans. Overall, some changes that can be expected include increased warming, a decrease in pH levels, decreases in dissolved oxygen (leading to more ‘dead spots’ of very low oxygen), and changes in salinity. For highly mobile animals such as sharks, it’s harder to study how these changes will impact them. Already we are seeing shifts in their swimming behavior and changes to migratory patterns, food availability and altered brain development are all predicted to occur if things continue the way they are.

Scanning electron micrographs show that the denticles of puffadder shysharks kept in pH 7.3 water for nine weeks (right) were substantially more degraded than those of sharks kept in normal ocean water (left).

Scanning electron micrographs show that the denticles of puffadder shysharks kept in pH 7.3 water ... [+]

J. DZIERGWA ET AL/SCIENTIFIC REPORTS 2019

But not all sharks are migratory. Some, like this slender benthic catshark, stay in one spot. Puffadder shysharks are endemic to the coast of South Africa, preferring the cold waters here to scavenge on crustaceans, polychaetes and small fishes. Camouflaged due to their sandy color and reddish saddles with dark and white spots, they tend to be seen as pests by local fishermen due to them eating bait off their hooks. While seen as a nuisance to some, they were a great study species since they have such a restricted range! The experiments, done in a lab, were carried out for nine weeks where after the researchers looked at the puffadder’s dermal denticles. On average, a quarter of the denticles on the sharks in acidic water were damaged, compared to 9.2 percent on the controls. “Damaged denticles may impact their ability to hunt or escape,” study co-author Lutz Auerswald, biologist at Stellenbosch University in South Africa, told Wired. “In addition, since sharks’ teeth are from the same material, corrosion may impact hunting and feeding.”

Ocean acidification is a major, but often less understood, concern for sharks. In fact, all sharks and their relatives (rays, skates, and chimaeras) have teeth and denticles made from this same material that seems to be vulnerable in increasingly acidic water. While done in a lab and only on one species, the results are still troubling. Our oceans may not get this acidic in the near future, but it’s just another hurdle for these animals to overcome. Currently they face more pressing threats such as overfishing and bycatch, habitat destruction, and even shark finning. But climate change shouldn’t be ignored. “The rate of climate change is very fast compared to previous changes,” says Auerswald. “Most likely, shark species will feel the impact differently and some may not be able to cope, whereas others may have the potential to adapt.”

Coral reefs with higher microbial diversity are much healthier, study finds

A collaborative study that compared seawater from 25 reefs in Cuba and the U.S. Florida Keys, which varied in human impact and protection, found that those with higher microbial diversity and lower concentrations of nutrients and organic carbon (primarily caused by human activities) were markedly healthier.

Researchers sampled seawater from each site and measured nutrients as well as a variety of other parameters that offer insight into the microbial community. They found a notable difference between the heavily protected offshore reefs in Cuba and the more impacted nearshore ones in the Florida Keys.

They found that exploring the connection between microorganisms and the health of coral reefs can be difficult due to the lack of unspoiled reef systems around the world.

“Human impacts such as overfishing and pollution lead to changes in reef structure,” says WHOI graduate student Laura Weber, lead author of the paper. “Removal of algae grazers such as herbivorous fish and sea urchins leads to increases in macroalgae, which then leads to increased organic carbon, contributing to the degradation of coral reefs.”

The study outlines how offshore and highly-protected reefs are healthier than nearshore reefs with less protection from human impacts. Additionally, reefs with lower nutrient runoff and carbon from industrial activities are markedly healthier.

“Cuba does not have large-scale industrialised agriculture or extensive development along most of its coastline,” says Patricia González-Díaz, Director of CIM-UH and co-author of the study. “So there is not a lot of nutrient run-off and sedimentation flowing on to the reefs.”

Additionally, the reefs of Jardines de la Reina, the largest protected area in the Caribbean, may be further buffered from impacts by the mangroves and seagrass meadows that lie between the island of Cuba and the reef system of Jardines de la Reina. Here, researchers found low concentrations of nutrients, and a high abundance of Prochlorococcus—a photosynthetic bacterium that thrives in low nutrient waters. More accessible and heavily-impacted areas in Florida Keys both contained higher organic carbon and nitrogen concentrations.

The work suggests that protection from a variety of human impacts does play a significant role in maintaining microbial diversity. The hope is that these findings could aid resource managers in deciding how best to protect and restore Caribbean coral reefs in the face of habitat and climate-based change.

To read the full paper, Microbial signatures of protected and impacted Northern Caribbean reefs: changes from Cuba to the Florida Keys,click here. Co-authors of the paper include colleagues from CIM-UH, Universidad Nacional Autónoma de México, Phillip and Patricia Frost Museum of Science, Mote Marine Laboratory, and the University of California, Santa Barbara.

Photograph by Amy Apprill, courtesy of Woods Hole Oceanographic Institution.

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