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.

Scientists Find Fossil of 150-Million-Year-Old Flesh-Eating Fish—Plus a Few of Its Prey

M. Ebert and T. Nohl
M. Ebert and T. Nohl

A fossil of an unusual piranha-like fish from the Late Jurassic period has been unearthed by scientists in southern Germany, Australian news outlet the ABC reports. Even more remarkable than the fossil’s age—150 million years old—is the fact that the limestone deposit also contains some of the fish’s victims.

Fish with chunks missing from their fins were found near the predator fish, which has been named Piranhamesodon pinnatomus. Aside from the predator’s razor-sharp teeth, though, it doesn’t look like your usual flesh-eating fish. It belonged to an extinct order of bony fish that lived at the time of the dinosaurs, and until now, scientists didn’t realize there was a species of bony fish that tore into its prey in such a way. This makes it the first flesh-eating bony fish on record, long predating the piranha. 

“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” Dr. Martina Kölbl-Ebert, the paleontologist who found the fish with her husband, Martin Ebert, said in a statement. “Sharks have been able to bite out chunks of flesh, but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."

Kölbl-Ebert, the director of the Jura Museum in Eichstätt, Germany, says she was stunned to see the bony fish’s sharp teeth, comparing it to “finding a sheep with a snarl like a wolf.” This cunning disguise made the fish a fearful predator, and scientists believe the fish may have “exploited aggressive mimicry” to ambush unsuspecting fish.

The fossil was discovered in 2016 in southern Germany, but the find has only recently been described in the journal Current Biology. It was found at a quarry where other fossils, like those of the Archaeopteryx dinosaur, have been unearthed in the past.

[h/t the ABC]

Could Leonardo da Vinci's Artistic Genius Be Due to an Eye Condition?

Young John the Baptist, Leonardo da Vinci (1513-16, Louvre, Paris).
Young John the Baptist, Leonardo da Vinci (1513-16, Louvre, Paris).
Christopher Tyler, JAMA Ophthalmology (2018)

Leonardo da Vinci was indisputably a genius, but his singular artistic vision may have been the result of seeing the world differently in more ways than one. A new paper argues that he had strabismus, a vision disorder where the eyes are misaligned and don’t look toward the same place at the same time. This disorder, visual neuroscientist Christopher Tyler argues, may have helped the artist render three-dimensional images on flat canvas with an extra level of skill.

Tyler is a professor at City, University of London who has written a number of studies on optics and art. In this study, published in JAMA Ophthalmology, he examined six different artworks from the period when Leonardo was working, including Young John the Baptist, Vitruvian Man, and a self-portrait by the artist. He also analyzed pieces by other artists that are thought to have used Leonardo as a model, like Andrea del Verrocchio’s Young Warrior sculpture. Leonardo served as the lead assistant in the latter artist’s studio, and likely served as the model for several of his works. Leonardo was also a friend of Benedetto da Maiano, and possibly served as a model for his 1480 sculpture of John the Baptist. Tyler also looked at the recently auctioned Salvator Mundi, a painting that not all experts believe can be attributed to Leonardo. (However, at least one scientific team that examined the painting says it’s legit.)

With strabismus, a person’s eyes appear to point in different directions. Based on the eyes in Leonardo’s own portraits of himself and other artworks modeled after him, it seems likely that he had intermittent strabismus. When he relaxed his eyes, one of his eyes drifted outward, though he was likely able to align his eyes when he focused. The gaze in the portraits and sculptures seems to be misaligned, with the left eye consistently drifting outward at around the same angle.

'Vitruvian Man' with the subject's pupils highlighted
Vitruvian Man, Leonardo da Vinci (~1490, Accademia, Venice)
Christopher Tyler, JAMA Ophthalmology (2018)

“The weight of converging evidence suggests that [Leonardo] had intermittent exotropia—where an eye turns outwards—with a resulting ability to switch to monocular vision, using just one eye,” Tyler explained in a press release. “The condition is rather convenient for a painter, since viewing the world with one eye allows direct comparison with the flat image being drawn or painted.” This would have given him an assist in depicting depth accurately.

Leonardo isn’t the first famous artist whose vision researchers have wondered about. Some have speculated that Degas’s increasingly coarse pastel work in his later years may have been attributed to his degenerating eyes, as the rough edges would have appeared smoother to him because of his blurred vision. Others have suggested that Van Gogh’s “yellow period” and the vibrant colors of Starry Night may have been influenced by yellowing vision caused by his use of digitalis, a medicine he took for epilepsy.

We can never truly know whether a long-dead artist’s work was the result of visual issues or simply a unique artistic vision, but looking at their art through the lens of medicine provides a new way of understanding their process.

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