Drone Captures Massive Swarm of Jellyfish Off British Columbia That Weighs More Than 70 Tons

Keith Holmes/Hakai Institute
Keith Holmes/Hakai Institute

Drones have served science in myriad ways, from planting trees to vacuuming marine debris to predicting tornadoes. Now, a team of researchers has used one to measure the size of a massive bloom of jellyfish off the coast of British Columbia, Canada. And it's a monster: According to a new paper in the journal Marine Ecology Progress Series, the huge swarm weighed more than 70 tons.

That's at least 150,000 individual jellies.

"The size of the bloom surprised me. What was exciting was going from not being able to see the bloom easily, if at all, to instantly being able to find them from the air," says co-author Brian Hunt, the Hakai Professor in Oceanography at the University of British Columbia in Vancouver, B.C. "It is remarkable how tightly they group together."

Jellyfish bloom in Pruth Bay, British Columbia
Keith Holmes, Hakai Institute

The bloom is comprised of five species in the Aurelia genus, also known as moon jellies. They're found worldwide (and in aquarium exhibits), often gathering in quiet harbors and bays to feed on plankton, fish larvae, crustaceans, and mollusks.

Hunt and colleague Jessica Schaub conducted their survey in Pruth Bay, a peaceful waterway edged with dense forests, near Calvert Island on the province's central coast, roughly 375 miles north of Seattle. The Hakai Institute, a scientific research institution that supported the survey, faces the bay. The area is within the First Nations territories of the Heiltsuk and Wuikinuxv Nations.

This is the first time a drone has been used to locate and study jellyfish blooms, Hunt tells Mental Floss. Previously, scientists viewed the groups at water level, which provided a limited perspective on their true size and density. The aerial view can help researchers estimate the biomass of jellyfish more accurately and reveal aggregations' behavior, such as their movements in currents or tides.

The team deployed the drone from a research vessel positioned within the mass of invertebrates. While the drone captured aerial images, the researchers also sampled the waters with nets. Then, they compared the drone data and sampling, and estimated that the bloom could weigh anywhere from 70 to as much as 128 tons.

Jellyfish bloom in Pruth Bay, British Columbia
Keith Holmes, Hakai Institute

There isn't much long-term data about the blooms, Hunt says, but those living in the area are familiar with the jellies' appearances in the waterways. "I wouldn’t call these events common, but they are definitely consistent in their timing. We see this happening every four or so years, particularly the local fisherman who catch them as bycatch in their nets," William Housty, chair of the Heiltsuk Integrated Resource Management Department's board of directors, tells Mental Floss.

In the future, drones might help scientists interpret the blooms based on where, when, and how often they occur—as well as how they affect the surrounding ecosystem. Housty says these jellyfish may be following the pattern of warmer waters along the coast.

"We did notice higher numbers during the 2015 marine heatwave and the 2016 El Niño [also a warm event]," Hunt says. "It is possible that changes in the seasonal timing of the jellyfish life cycle might be as or more important than increasing numbers. For example, if jellyfish are more advanced in their life cycle in the spring, they might have a bigger predation impact on herring larvae."

Soon, thanks to aerial imagery, we might know more about the jellies' secret lives.

This story was made possible in part through the Institute for Journalism and Natural Resources.

Bombshell, Victoria’s Secret’s Bestselling Fragrance, Also Happens to Repel Mosquitoes

Dids, Pexels
Dids, Pexels

People love Bombshell, the best-selling fragrance at Victoria’s Secret, for its summery blend of fruity and floral notes. Not everyone is a huge fan, though: As Quartz reports, the perfume is surprisingly good at warding off mosquitoes. In fact, it’s almost as effective as DEET insect repellent, according to the results of a 2014 experiment by researchers at New Mexico State University.

Researchers took 10 products that are commercially available and tested their ability to repel two different species of mosquitoes: the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), both of which are known to transmit diseases like dengue fever, chikungunya, and yellow fever. In doing so, volunteers subjected their own flesh to the test by placing their hands on either side of a Y-shaped tube containing the blood-sucking critters. One hand was covered in a synthetic rubber glove, while the other hand was sprayed with one of the products but otherwise left bare. Researchers recorded which tunnel the mosquitoes flew to, and how long they avoided the other end.

Three of the products contained DEET, while four products didn’t. In addition, there were two fragrances (including Bombshell) and one vitamin B1 skin patch. The DEET products were the most effective, but Bombshell proved to be nearly as good, keeping mosquitoes at bay for roughly two hours.

“There was some previous literature that said fruity, floral scents attracted mosquitoes, and to not wear those,” Stacy Rodriquez, one of the study’s authors, said in a statement. “It was interesting to see that the mosquitoes weren’t actually attracted to the person that was wearing the Victoria’s Secret perfume—they were repelled by it.”

This isn’t the first time a perfume has had an unintended effect on the natural world. It turns out that tigers are obsessed with Calvin Klein’s Obsession for Men cologne, partly because it contains a synthetic version of civetone, a pheromone that's secreted by glands located near a civet’s anus. This substance was once used to create musky fragrances, but nowadays the scent is mostly reproduced in a lab. Still, the fake stuff must be pretty convincing, because big cats go crazy when they catch a whiff of it.

[h/t Quartz]

Mystery Solved: Scientists Have Figured Out Why Some Squirrels Are Black

Rena-Marie/iStock via Getty Images
Rena-Marie/iStock via Getty Images

It can be something of a surprise to see an animal sporting a fresh coat of paint. Blue lobsters occasionally surface after being caught in traps. A pink dolphin was spotted in Louisiana in 2007 (and several times since). In the Chinese province of Shaanxi, a cute brown and white panda greets zoo visitors.

Another anomalous animal has joined their ranks. Black squirrels have been spotted in both the United States and the UK, and now scientists believe they know why.

Like many animals with unusual color schemes, black squirrels are the result of a genetic detour. Researchers at Anglia Ruskin University, Cambridge University, and the Virginia Museum of Natural History collaborated on a project that tested squirrel DNA. Their findings, which were published in BMC Evolutionary Biology, demonstrated that the black squirrel is the product of interspecies breeding between the common gray squirrel and the fox squirrel. The black squirrel is actually a gray squirrel with a faulty pigment gene carried over from the fox squirrel that turns their fur a darker shade. (Some fox squirrels, which are usually reddish-brown, are also black.)

A black squirrel is pictured
sanches12/iStock via Getty Images

Scientists theorize a black fox squirrel may have joined in on a mating chase involving gray squirrels and got busy with a female. The black fur may offer benefits in colder regions, with squirrels able to absorb and retain more heat, giving them a slight evolutionary edge.

In North America, black squirrels are uncommon, with one estimate putting them at a rate of one in every 10,000 squirrels. In 1961, students at Kent State University in Ohio released 10 black squirrels that had been captured by Canadian wildlife authorities. The squirrels now populate the campus and have become the school’s unofficial mascot. Their coloring might help them hide from predators, which might come in handy at Kent State: The campus is also home to hawks.

[h/t The Guardian]

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