Day: September 21, 2017

Sea turtles are lumbering back from the brink of extinction, a new study says.

Scientists found more populations of the large turtles improving than declining when they looked at nearly 60 regions across the globe. That’s a big change from a decade or two ago, experts said.

Long-living sea turtles have been pushed to endangered levels by hunting, accidentally being caught in fishing nets, habitat loss, plastics pollution and climate change, experts say.

But massive efforts to save the egg-laying turtles by changing fishing nets and creating protected and darkened beaches are working, said study lead author Antonios Mazaris, an ecology professor at Aristotle University of Thessaloniki in Greece.

“There’s a positive sign at the end of the story,” Mazaris said. “We should be more optimistic about our efforts in society.”

Seven species of sea turtles

The research was published Wednesday in the journal Science Advances.

There are seven different species of sea turtles, all but one endangered. The slow creatures live for several decades with some species weighing about 100 pounds and others well over 1,000 pounds.

Mazaris pointed to Hawaiian green sea turtles, once in trouble 40 years ago, as story of success. Maybe too much success.

“They have more turtles than they know what to do with,” said Roderic Mast, a sea turtle advisory group co-chairman at the International Union for Conservation of Nature, which determines the global list of endangered species.

‘Good problem to have’

“Tourists seeking sea turtles create traffic problems and fishermen complain the creatures get in the way, said Mast, who wasn’t part of the study and is president of the Oceanic Society advocacy group. He added: “It’s a good problem to have.”

Mazaris and colleagues looked at 299 sets of turtle populations over different lengths of time around the globe, finding 95 of them increased, while 35 went down. The rest didn’t change or there wasn’t enough data.

 There were increases in North and South America on the Atlantic coast but setbacks in the Asia Pacific region.

 “The evidence is widespread and convincing,” said Selina Heppell, head of Oregon State University’s department of fisheries and wildlife, who wasn’t part of the study.

Changes in laws make difference

Mast pointed to Kemp’s ridley sea turtles as a good example of what’s happening, especially in the United States.  In the 1940s, there about 40,000 of them, mostly in the southern U.S. and Mexico. By the 70s, there were only 1,200 left.

The U.S. and Mexican governments changed laws, fishing practices and set aside dark, quiet areas for turtles to nest. That population is increasing by about 10 to 15 percent annually, Mast said. That’s good, but he said they remain critically endangered.

“Sea turtles are bellwethers. They’re flagships that we use to tell the story of what’s going on in the oceans,” Mast said. “And that’s why people should care about turtles.”

 
…

British scientists have used a genome editing tool known as CRISPR/Cas9 to knock out a gene in embryos just a few days old, testing the technique’s ability to decipher key gene functions in early human development.

The researchers said their experiments, using a technology that is the subject of fierce international debate because of fears that it could be used to create babies to order, will deepen understanding of the biology of early human development.

CRISPR/Cas9 can enable scientists to find and modify or replace genetic defects. Many describe it as game changing.

Role of key gene

“One way to find out what a gene does in the developing embryo is to see what happens when it isn’t working,” said Kathy Niakan, a stem cell scientists who led the research at Britain’s Francis Crick Institute. “Now we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes.”

She said her hope was for scientists to decipher the roles of all the key genes embryos need to develop successfully. This could then improve IVF treatments for infertile couples and also help doctors understand why so many pregnancies fail.

“It may take many years to achieve such an understanding, our study is just the first step,” Niakan said.

No gene, no protein

Niakan’s team decided to use it to stop a key gene from producing a protein called OCT4, which normally becomes active in the first few days of human embryo development.

They spent more than a year optimizing their various techniques using mouse embryos and human embryonic stem cells in lab dishes, before starting work on human embryos.

To inactivate OCT4, they used CRISPR/Cas9 to change the DNA of 41 human embryos. After seven days, embryo development was stopped and the embryos were analyzed.

After an egg is fertilized, it divides for about seven days when it forms a ball of around 200 cells called a blastocyst, Niakan explained in a briefing about her work.

Her results, published in the journal Nature on Wednesday, found that human embryos need OCT4 to form a blastocyst. Without it, the blastocyst cannot form or develop normally.

US research

The British team’s work comes on the heels of milestone science in the United States, where scientists said in July they had succeeded in altering the genes of a human embryo to correct a disease-causing mutation.

Rob Buckle, chief science officer at Britain’s Medical Research Council, praised Niakan’s research and findings: “Genome editing technologies — particularly CRISPR-Cas9 used in this study — are having a game-changing effect on our ability to understand the function of critical human genes,” he said.

 
…

Whether children live in Baltimore, Beijing, Nairobi or New Delhi, by the time they are 15, boys are told to go outside and have adventures, while girls are told to stay indoors and do housework. Furthermore, most girls are told that if they are raped or have sex, they are the ones at fault.

A new study by adolescent-health specialists interviewed 450 poor children and their parents about gender expectations in a total of 15 high-, low- and middle-income countries. The children included in the study, the first of its kind, were between the ages of 10 and 14.

“When we started this work, there was no research at all, no understanding at all of young adolescents,” said Robert Blum, director of the Global Early Adolescent Study at Johns Hopkins University in Baltimore, Maryland. “There was an assumption that these were young children, and they aren’t cued into gender-based violence, gender messages, rape and things of that nature.

“What we see is that around the world, young people have keen awareness, and they’re very cued in to what’s going on.”

The key finding was that rigidly held and enforced gender expectations are linked to increased lifelong health risks — everything from HIV and depression to violence and suicide.

Messages internalized

“We found children at a very early age, from the most conservative to the most liberal societies, quickly internalize this myth that girls are vulnerable and boys are strong and independent,” Blum told VOA. “And this message is being constantly reinforced at almost every turn, by siblings, classmates, teachers, parents, guardians, relatives, clergy and coaches.”

The researchers found that in most cultures, by the time girls are 10 years old, they have been taught that their key asset is their physical appearance.

Lead researcher Kristin Mmari said no matter where they are, girls are concerned about their bodies, and others’ attitudes to them. “In New Delhi, the girls talked about their bodies as a big risk that needs to be covered up, while in Baltimore, girls told us their primary asset was their bodies and they need to look appealing, but not too appealing.”

Venkatraman Chandra-Mouli of the World Health Organization said violence against women is so pervasive that one in three women experience violence from their husbands or other sexual partners. “Social norms accept that a woman has to be beaten,” Chandra-Mouli said.

He and other researchers involved in the study of adolescents’ gender norms discussed their findings at the National Press Club in Washington.

Pressure on boys

The researchers found that boys do not emerge unscathed from gender expectations. They found that the pressure boys face to become physically strong and independent make them more likely to be victims of physical violence and homicide, and more likely to take up unhealthy habits like tobacco, drug and alcohol use.

The study was a collaboration between the Johns Hopkins Bloomberg School of Public Health and the World Health Organization. The Journal of Adolescent Health has published a supplement to its October issue incorporating a number of articles on the subject, along with commentaries by Blum, Chandra-Mouli and others.

Adolescents are torn between opposing expectations, the study showed, especially girls.

In Shanghai, for example, girls are told they should be economically independent, and that they should not rely on men for financial support. At the same time, girls are told their husbands will divorce them if they don’t do housework.

The goal was to understand the factors in early adolescence that predispose young people to subsequent sexual health risks and promote healthy sexuality.

The conclusion was that societies wishing to have healthier adolescents and young adults, free of gender stereotypes, must intervene, where necessary, before children reach age 10. Chandra-Mouli said WHO hopes to use the data from the study to shape programs to change misunderstandings about gender norms.

Blum said the researchers will measure changes in their subjects three times over five years to see how perceptions of gender affect individuals’ lives and how programs change the outcome.
…

In a remote, rugged valley overlooking the Pacific Ocean, researchers closely monitor an endangered icon: the California condor.

The giant vultures flap their wings and circle the sky before perching on branches and observing their observers.

Wildlife biologist Amy List uses a handheld antenna to track the birds, which wear radio transmitters and numbered tags.

“If we don’t know what they’re doing, we don’t know what’s going wrong,” said List, who works for the Ventana Wildlife Society, which manages the condor sanctuary in Big Sur.

Three decades after being pushed to the brink of extinction, the California condor is making a comeback in the wild, but constant vigilance is needed to ensure the endangered bird doesn’t reverse course.

One of the world’s largest birds with a wingspan up to 10 feet, the condor once patrolled the sky from Mexico to British Columbia. But its population plummeted in the 20th century due to lead poisoning, hunting and habitat destruction.

In 1987, wildlife officials captured the last remaining 22 condors and took them to the San Diego and Los Angeles zoos to be protected and bred in captivity.

Those efforts have led to a slow but steady recovery for a species that reproduces slowly compared with other birds. There are now roughly 450 condors, including about 270 in the wild in California, Arizona, Utah and northeastern Mexico.

Plans also are underway to release some captive-bred condors in Redwood National Park in 2019 to establish a population near the California-Oregon border.

Federal officials said in August that for the first time in nearly 40 years, condors were roosting in the Blue Ridge National Wildlife Refuge, expanding to their historical range in the southern Sierra Nevada.

Another milestone was reached this summer: the first “third generation” condor was born in the wild in California since the 1980s.

“We’re seeing very encouraging results that the condors can become self-sustaining again,” said Kelly Sorenson, who heads the conservation group.

While condors still face threats from exposure to mercury and the pesticide DDT, biologists say the biggest danger is lead ammunition, which can poison the scavengers when they eat dead animals shot with lead bullets. California banned the use of lead ammunition near condor feeding grounds in 2008 and will be the first state to ban lead bullets in all hunting in 2019.

“We’re already starting to see fewer lead deaths. The condors are surviving longer. Their blood-lead levels are coming down,” Sorenson said.

Some gun owners complain that copper bullets are more expensive and less effective than lead and point to other possible sources of lead, such as paint and metal garbage.

“Condors are getting lead poisoning. The question is, are they getting it from lead ammunition?” said Chuck Michel, president of the California Pistol and Rifle Association.

Meanwhile, the San Diego Zoo celebrated the birth of its 200th condor this year.

“While we were caring for the birds, trying to protect them and provide sanctuary, we were literally writing the book how you propagate a species, how you genetically manage it and prepare it for release back in the wild,” Michael Mace, the zoo’s birds curator.

After up to a year at the zoo, chicks are taken to a release site such as the Big Sur sanctuary, where a flock has grown to about 90 condors that travel between Big Sur and Pinnacles National Park. They scavenge, breed and raise chicks on their own, under the close watch of List, the wildlife biologist, and her colleagues.

“I hope that I’m out of a job soon because condors don’t need to be managed in the future,” she said. “I hope that they’re self-sustaining and wild and free, and nobody needs to trap or tag or monitor them at all.”
…