Scientists Can Tell If Great White Sharks Are Around by Testing DNA in Seawater

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iStock

Love the beach but fear sharks? Your risk of dying in a shark attack is infinitesimal—roughly 1 in 3.7 million—but it’s still a risk nonetheless. Scientists say white sharks are becoming more prevalent along California’s coast thanks to federal protections, and on the opposite side of the country, Cape Cod recently saw its first fatal shark attack in more than 80 years.

A new proof-of-concept study, published in Frontiers in Marine Science, could shed new light on what's lurking beneath the surface. Researchers from UC Santa Barbara, the U.S. Geological Survey, and partner universities theorized that environmental DNA (eDNA)—an organism's cast-off bits of genetic material—could show the presence of white sharks in a particular part of the California coast.

White sharks forge distinctive trails by shedding skin and discharging mucus, feces, and other genetic markers in seawater. Researchers created a species-specific test for white shark eDNA, then rode stand-up paddleboards to four sites beyond the line of surf to collect water samples. After analyzing the samples in the lab, they found white shark eDNA in two samples from areas where the fish were known to gather, and no eDNA in the other two samples from sites where sharks hadn't been observed. The results from the preliminary experiment showed that the new test could accurately identify the sharks' eDNA—and that might save a surfer in the future.

"One of the goals of this research is for a lifeguard to be able to walk down to the shore, scoop up some water, shake it, and see if white sharks are around," Kevin Lafferty, lead author of the study, said in a statement.

The use of eDNA has some limitations. Ocean currents can cause eDNA to drift, and that genetic information can degrade quickly in the surrounding environment. “Another challenge is that eDNA might persist in the ocean environment for days, meaning a positive detection might indicate a species that is no longer locally present,” the researchers write in their paper. Still, they say the development is a step in the right direction for better shark monitoring and conservation efforts.

The Reason Why a Puppy in North Carolina Was Born Bright Green

Anastasiia Cherniavskaia, iStock via Getty Images
Anastasiia Cherniavskaia, iStock via Getty Images

When a dog owner in Canton, North Carolina, first saw her new puppy, she knew exactly what to name him. Hulk the infant pup is much smaller than his namesake, but like the comic book character, he's green from head to toe.

As WLOS reports, Hulk was born with a coat of fur the color of avocado toast. He is one of eight puppies in a litter a white German Shepherd named Gypsy delivered the morning of January 10. Even though one came out lime-green, it was healthy, normal birth, according to Gypsy's owner Shana Stamey.

Hulk's unique coloration isn't a sign of any health issues. Meconium—or the matter in the intestines of a fetus—is mostly made of water, but it can also contain something called biliverdin. This chemical makes bile, and when it gets into the amniotic fluid of a birth sac, it can stain a puppy's fur green. This is especially noticeable when the newborn's fur is white, as in Hulk's case. You can see the rare phenomenon in the video below.

After a few weeks of baths and licks from mom, the meconium stains will eventually fade to reveal his natural white coat. But while he won't be green forever, Hulk gets to keep his colorful name for life.

[h/t WLOS]

Not-So-Fancy Feast: Your Cat Probably Would Eat Your Rotting Corpse

Tycson1/iStock via Getty Images
Tycson1/iStock via Getty Images

Cat enthusiasts often cite the warmth and companionship offered by their pet as reasons why they’re so enamored with them. Despite these and other positive attributes, cat lovers are often confronted with the spurious claim that, while their beloved furry pal might adore them when they’re alive, it won’t hesitate to devour their corpse if they should drop dead.

Though that’s often dismissed as negative cat propaganda spread by dog people, it turns out that it’s probably true. Fluffy might indeed feast on your flesh if you happened to expire.

A horrifying new case study published in the Journal of Forensic Sciences offers the fresh evidence. The paper, first reported by The Washington Post, documents how two cats reacted in the presence of a corpse at Colorado Mesa University’s Forensic Investigation Research Station, or body farm, where the deceased are used to further forensic science for criminal investigations.

The study’s authors did not orchestrate a meeting between cat and corpse. The finding happened by accident: Student and lead author Sara Garcia was scanning surveillance footage of the grounds when she noticed a pair of cats trespassing. The cats, she found, were interested in the flesh of two corpses; they gnawed on human tissue while it was still in the early stages of decomposition, stopping only when the bodies began leaching fluids.

The cats, which were putting away one corpse each, didn’t appear to have a taste for variety, as they both returned to the same corpse virtually every night. The two seemed to prefer the shoulder and arm over other body parts.

This visual evidence joins a litany of reports over the years from medical examiners, who have observed the damage left by both cats and dogs who were trapped in homes with deceased owners and proceeded to eat them. It’s believed pets do this when no other food source is available, though in some cases, eating their human has occurred even with a full food bowl. It’s something to consider the next time your cat gives you an affectionate lick on the arm. Maybe it loves you. Or maybe it has something else in mind.

[h/t The Washington Post]

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