Whaling has left a huge hole in the ocean’s food chain

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Analysis of hundreds of COVID-19 cases suggests where face masks matter most: during long dates and indoors. Researchers studied more than a thousand people in California who tested positive for SARS-CoV-2 between February and September 2021. Each of these was associated with at least one control participant: a person with the symptoms. same factors, such as age and gender, but tested negative during this time. Participants who had been exposed to someone known to have COVID-19 provided details about the encounter, such as the setting and duration. The study, which has yet to be peer-reviewed, found that participants who were not fully vaccinated had the greatest risk of infection when they reported exposure to someone with COVID-19. that had occurred indoors or had lasted for more than three hours. Participants exposed to someone with COVID-19 had a lower risk of infection if masks were worn during the encounter than if they were not.

Nature | 4 minutes to read

Reference: medRxiv preprint (not peer reviewed)

A long-awaited roadmap for the next ten years of American astronomy has just fallen, and it is super ambitious. He recommends that NASA coordinate, build and launch three flagship space observatories capable of detecting light over a wide range of wavelengths. He suggests that the United States’ National Science Foundation fund two huge ground-based telescopes in Chile and possibly Hawaii, in an attempt to catch up with an advanced European telescope under construction. And for the first time, it’s making recommendations on how federal agencies should tackle systemic racism, sexism, and other structural issues that drive people out of astronomy, undermining the quality of science.

Nature | 8 minutes to read

Whales eat up to three times more prey than previously thought. Their droppings once fed a rich underwater ecosystem that has been devastated by whaling. Researchers tagged whales and monitored krill to directly observe the feeding habits of baleen whales, such as humpback whales (Megaptera novaeangliae) and the blue whales (Balaenoptera musculus). With around 2 million animals killed by whalers in the twentieth century – a mass twice as large as all wild mammals on Earth today – that means around 430 million tonnes of krill went uneaten. This iron-rich poop never sank to fertilize the ocean’s food chain, breaking an iron cycle that nourished everything from diatoms to seabirds. People may be able to help restore these once-upon-a-time ecosystems. rich, researchers say, by sowing the ocean with iron that ultimately encourages the whale population to bounce back and do the job itself.

The Atlantic | 6 minutes to read

Read the expert opinion of bio-oceanographer Victor Smetacek in the Nature News & Views article (7 min read, Nature paywall)

Reference: Nature paper

When whales eat krill, they aid the iron cycle by defecating iron-rich leftovers. They can also promote iron availability by mixing ocean waters with their vigorous tail movements. Since the availability of iron limits productivity in ocean waters, this has fueled a rich food web – which large-scale whaling has disrupted. (Nature News & Views article | 7 min read, Nature paywall)

Image of the week

This tiny tardigrade has been preserved in amber for 16 million years. Researchers studied the fragment for months before spotting the half-millimeter-long creature in a corner. The discovery is “truly a once-in-a-generation event,” says entomologist Phil Barden. This is only the third fossilized tardigrade to be found, and the first from the Cenozoic, the current geological era. The fossil specimen – a genus and species new to science – was named Paradoryphoribius chronocaribbeus.

See more of the month’s sharpest science photos, curated by Naturethe photo team of.