AFP

Vaquita porpoises are on the edge of extinction, with just 10 left in their sole habibat within Mexico’s Gulf of California.

However, a new study published Thursday in the journal Science offers some hope: the world’s rarest marine mammals aren’t doomed by a lack of genetic diversity, and can recover if illegal “gillnet” fishing ceases immediately. 

“We’re trying to push back on this idea that there’s no hope, that nothing we do could save them at this point. It’s just not an accurate assumption,” lead author Jacqueline Robinson of the University of California San Francisco told AFP.

Porpoises are closely related to dolphins, and share many things in common including great intelligence. 

The vaquita, whose name means “little cow” in Spanish, measures four to five feet (about 1.5 meters) in length, making it the smallest of all cetaceans.

Shy and elusive, they are known for distinctive dark circles around their eyes, and relatively large dorsal fins, which are thought to help them dissipate heat in their warm habitat.

Vaquita numbers were decimated in the 20th century as a result of being accidentally trapped and drowning in gillnets: long walls of nets hanging in open water that are used to catch fish and shrimp. 

Fishermen sought in particular the totoaba, a large fish about the size of the vaquita, whose swim-bladder is prized in traditional Chinese medicine.

The totoaba itself is endangered and its fishing is illegal, but the ban isn’t always respected.

The vaquita’s historical abundance was unknown, but by the time of the first survey, in 1997, only around 570 remained.

There were fears that harmful mutations among the surviving vaquitas could seal the species’ fate due to inevitable inbreeding.

To find out whether that was the case, the researchers analyzed the genomes of 20 vaquitas that lived between 1985 and 2017, and discovered that over the past 250,000 years their population had never exceeded a few thousand.

They also learned that their genetic diversity had always been low, relative to other cetacean species such as dolphins, orcas, and other whales. 

– Benefits to low genetic diversity –

“Generally, we would think of low genetic diversity as being a bad thing. But in this case, it is somewhat advantageous for the vaquitas for their possibility of future recovery,” said Robinson. 

Inbreeding increases the chances offspring will inherit two copies of harmful mutations, leading to genetic disorders.

But it turned out that the frequency of these mutations are very low in vaquitas to begin with, because the population has always been small.

“So those mutations were historically weeded out much more effectively, than in a larger population, where those mutations could persist and remain hidden from natural selection,” explained Robinson.

There are other species that appear more resistant to so-called “inbreeding depression,” including mountain gorillas and narwhals, for similar reasons.

The team then carried out simulations to forecast the species’ future. 

Encouragingly, there is only a six percent chance of vaquitas’ extinction if gillnet fishing is eliminated.

But if such fishing is only reduced, then the extinction risk rises drastically. 

Even with an 80 percent reduction in fishing, the porpoises have a 62 percent chance of disappearing.

“While we now know that the species’ ability to recover is not limited by their genetics, vaquitas have very little time left,” said co-author Christopher Kyriazis of the University of California, Los Angeles, in a statement.

“If we lose them, it would be the result of our human choices, not inherent genetic factors.”

Food is fundamental to the efforts to tackle climate change, according to a scientist who has spent decades tracing the interactions between global warming and what we eat. 

Cynthia Rosenzweig, head of the Climate Impacts Group at NASA Goddard Institute for Space Studies, was Thursday awarded the prestigious World Food Prize for her research. 

That includes stark warnings about the potential effect climate change will have on food. 

Her comments to AFP have been slightly edited: 

– How do food systems drive climate change? 

Climate change cannot be restrained without attention to greenhouse gas emissions from food systems. Our work, among others, shows that those food system emissions are approximately one third of total human emissions. We’re not going to be able to solve climate change unless these are taken into account. 

At the same time, food security for all is dependent on the changing climate. 

As we move into this crucial decade of action on climate change, food needs to be at the table.

– What are the climate impacts on food?

High temperatures in general are detrimental to crops, because they speed them through their growing period, so they have less time to make the grain. So this is a very big downward pressure on yield. Then we have extreme events affecting the critical growth stages, for example, a heatwave happening during pollination in maize. Those extreme events are already increasing in frequency, duration and intensity in many farming regions around the world. 

Then of course water is absolutely critical for food production. Climate change is projected to change — and is already changing — the hydrological cycle in many agricultural areas, with increased drought as well as heavier downpours because the warmer air holds more water vapour. 

We can already see tremendous impacts of drought in the developed world, for example, in California since the 2000s. In the developing world, there isn’t as much breeding for heat and drought tolerance in farming, there isn’t as much work on pests. This increases tremendously the vulnerability of the world’s 500 million smallholder farmers.

– You founded the Agricultural Model Intercomparison and Improvement Project. What does it do?

There used to be different modelling groups around the world, all working very diligently to develop different crop models. But people would be using different climate scenarios to test climate change impacts — and the results weren’t comparable. So at the heart of AgMIP is improving the rigour of the projections by developing common protocols so that the results from agricultural models can be compared. We do crop modelling, livestock modelling, pest modelling and economic modelling and we always bring in the latest climate scenarios.

Therefore we are able to say in a very clear way: here’s the mean of the model results and here’s the range of the projections. Then decision makers, both at the global scale but also in individual countries, have the evidence base that they need to respond to climate change effectively. 

With the latest climate scenarios, AgMIP’s Global Gridded Crop Modelling Team found that the emergence of impacts on some of the agricultural regions around the world is now projected to be felt earlier, to really start biting even in the 2030s. That’s really soon.

Some of the key areas with these earlier impacts are parts of the US Midwest, Western Africa and East Asia. In West Africa, crop yields are projected to fall by 20 to 40 percent, and potentially more.

– What changes could help cut emissions?

Increasing carbon storage can help to fight climate change. We need to increase efficiency for crop production and reduce food loss and waste — it’s a rough figure but around a third of all food produced is lost or wasted. If we don’t waste as much food, we don’t have to grow as much food — thereby reducing greenhouse gas emissions from agricultural production. 

In developed countries, there’s definitely the potential for dietary choices to make an impact, because animal-based emissions, especially from beef and dairy, are significant. But as we think about consumption, we have to start by saying that all solutions are context specific and they have to take into account equity issues. There are many people in the world who don’t have food choices. 

– Are perceptions changing? 

Yes. I interact with so many different groups in all different parts of the food system, from the production side, supply chain side, retail, packaging, everything. There is definitely a movement towards transformation going on in the food system. 

Food is the fundamental climate impact sector and connects everyone on the planet to climate change. We need to transform the food system, so that it delivers food security for all, as well as a healthy and sustainable planet.

An Italian surgeon once hailed for pioneering windpipe surgery but now charged with assault told a Swedish court Thursday the experimental procedures were the result of “teamwork” and that he just wanted to save lives.

Paolo Macchiarini won praise in 2011 after claiming to have performed the world’s first synthetic trachea transplants using stem cells, while he was a surgeon at Stockholm’s Karolinska University Hospital.

The experimental procedure was hailed as a breakthrough in regenerative medicine.

But allegations soon emerged that the procedure had been carried out on at least one person who had not been critically ill at the time of the surgery.

Together with his colleagues, Macchiarini, 63, performed a total of eight such transplants between 2011 and 2014 — three in Sweden in 2011 and 2012, and five in Russia.

The three patients in Sweden died, though the deaths have not been directly linked to the surgeries.

Last week, prosecutors spent three days arguing that the surgeries in Sweden constituted assault, or alternatively bodily harm due to negligence, as Macchiarini disregarded “science and proven experience.”

The surgeon addressed the court for the first time on Thursday.

“I have been silent all these years, and it’s because my lawyers said to do so. Because we believe that the only judgement that is right should come from a legal court,” Macchiarini said in an opening statement.

– ‘Not alone’ –

Macchiarini insisted several times that the transplants were an alternative decided upon after all other options had been excluded — what he referred to as a “Plan B”.

Macchiarini’s lawyer, Bjorn Hurtig, meanwhile insisted that the surgeries were the result of “teamwork” and had been discussed with other senior colleagues.

“Paolo Macchiarini was not alone in planning and making decisions,” Hurtig told the court, presenting medical notes and references to conferences where the transplants were discussed.

Chief prosecutor Jim Westerberg told AFP on Wednesday he believed that Macchiarini had acted with “reckless intent”, arguing that he had continued performing the surgeries even though complications arose with earlier ones.

Defence lawyer Hurtig pointed however to emails from Macchiarini to colleagues, where he stressed the serious nature of his patients’ conditions and his desire to try and save their lives.

In one case, of a 37-year-old man from Eritrea studying in Iceland, other doctors had suggested treatments such as palliative care.

Hurtig presented an email where Macchiarini argued that “we should at least try to save the life of this student”.

Hurtig also presented emails that appeared to show one patient’s symptoms improving following the surgery.

Paolo Macchiarini “had but one intent, and that was to do good,” the lawyer said.

In 2013, the Karolinska Hospital suspended all trachea transplants and refused to extend Macchiarini’s contract as a surgeon.

A year later, several surgeons at the hospital filed a complaint alleging that Macchiarini had downplayed the risks of the procedure.

– Reopened investigation –

Macchiarini was also employed by the Karolinska Institute research facility, which awards the Nobel Medicine Prize. An external review in 2015 found Macchiarini guilty of research misconduct. 

Even though the Institute sacked him in 2016, it repeatedly defended him until 2018, when its own review found him and several other researchers guilty of scientific misconduct.

The university’s principal and several others stepped down over the scandal.

Medical journal The Lancet in 2018 retracted two papers authored by Macchiarini.

A criminal investigation was closed in 2017, only to be reopened in December of 2018 and charges were finally filed in September of 2020.

The trial, held in the Solna district court near the Karolinska Institute, is scheduled to conclude on May 23.

NASA’s Crew-3 mission was returning home to Earth on Thursday after six months aboard the International Space Station.

The SpaceX Dragon Endurance spacecraft with NASA astronauts Kayla Barron, Raja Chari, and Tom Marshburn, as well as European Space Agency astronaut Matthias Maurer undocked from the orbital laboratory overnight.

Their 23.5 hour journey back should see them splash down off the coast of Florida at 12:43 am on Friday (0443 GMT).

They leave behind the one Italian and three American astronauts of Crew-4, and three Russian cosmonauts. Ahead of departure, Marshburn handed command of the station over to Russian Oleg Artemyev.

During their mission, Crew-3 carried out hundreds of scientific experiments, including growing chiles in space to add to knowledge of cultivating crops on long term missions, exploring how concrete hardens in space, and Earth monitoring.

“Every day on @Space_Station is #EarthDay for @NASA_Astronauts since we see how thin the precious layer is that protects everything we know & love as a human race,” Crew-3 commander Chari wrote in a tweet.

“Hopefully, @NASA research will help w/ H20 purification & carbon dioxide reductions but the rest is up to us.”

Chancellor Olaf Scholz wished Maurer, the 12th German in space, “a good and safe journey back with a soft landing,” thanking him on Twitter for “all the new discoveries in space that are so important for us here on Earth.”

Crew-3’s expedition came at an increasingly busy time for commercial space. 

They welcomed aboard a private crew that included three wealthy businessmen that came and went on another SpaceX Crew Dragon, as well as a Japanese mission that flew on a Soyuz aircraft to the Russian segment.

The ISS now awaits docking with an uncrewed Boeing Starliner capsule, which is set to launch from Florida on May 19. 

NASA is looking to certify a second company to ferry astronauts to the region of space called Low Earth Orbit, leaving it to develop its super heavy space launch system (SLS) rocket for missions to the Moon, and eventually Mars.