Absurd because it sounds, this video of a stingray snacking on shellfish could be the most soothing scene that’s floated throughout our screens this yr.
However for the marine biologists who captured the recording, the listening expertise is extra than simply an ASMR thrill. Shark and ray researchers from Florida Atlantic College used a battery-powered digital camera with a hydrophone (the underwater equal of a microphone) to snoop on captive noticed eagle rays. Their purpose was to see if they might infer how the flat-toothed predators crushed their prey with out disturbing their meal time.
By measuring the frequencies of the pops, cracks, and crunches within the clips, the group appropriately guessed the rays’ meal, which included a menu of laborious clams, banded tulip snails, and 6 different mollusk species, in additional than 400 feeding occasions.) In addition they gauged the depth of shell fractures from the sounds to find out their distinctive technique of munching, says Catherine Lamboy, an creator on the research, which got here out within the Journal of Experimental Marine Biology and Ecology earlier this month. With their fused dental plates, the predators had little bother snapping the shellfish to get to the meaty insides. However the eight-foot-long rays didn’t all the time get it on the primary attempt. “Typically they’d put the mollusk of their mouth the incorrect means after which should spit it out,” Lamboy explains.
The most important takeaway from the analysis, nevertheless, was much less concerning the hungry sea creatures and extra concerning the underwater recorders. As Lamboy and her colleagues wrote of their paper, the success of their experiment exhibits that acoustic monitoring may play a hefty function in fixing looming marine mysteries, like that of the dramatic disappearance of many shark and ray species. “The expertise lets us collect data on predators with out dragging folks, noise air pollution, and tons of plastic tools into the ocean,” Lamboy says. “That is each crucial in preserving ecosystems and limiting our affect on animal actions and behaviors as we research them.”
However as Lamboy factors out, recording wildlife within the huge open ocean received’t be as seamless as doing it in a sand-bottomed tank. Circumstances at sea are by no means fixed: The slightest tweaks in strain, temperature, and salinity can change how sound travels by the water. There’s additionally the problem of the price of dear tools just like the Cyclops digital camera system used within the research and injury from the moist, salty parts.
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Nonetheless, the advantages of a hands-off strategy appears to outweigh the technological trickiness. Lamboy can see hydrophones coming in helpful to review how sharks (her fundamental analysis group) “hear” and hunt their prey. She’d additionally like for all of the recordings to finish up in some type of digital library, in order that whale, fish, and mollusk scientists can come collectively to create a big-picture soundscape of the ocean. “We are able to use it to know the anthropogenic impact on our planet’s waters,” she says. “However we are able to additionally benefit from the expertise whereas we’re at it.”