A Magnapinna squid swimming horizontally. Photo: Deborah Osterhage/Great Australian Bight Deepwater Marine Program.
A sighting of one of the deep ocean’s most mysterious beings, the bigfin squid, in Australian waters for the first time is creating waves among the scientific community’s squid squad.
“It seems other-worldly, and although some people find them a bit spooky, I find their coloration delicate, and their flapping fins and trailing arms quite calming to watch,” said Deborah Osterhage, first author of a new paper in PLOS ONE detailing the findings.
Surveys over the course of three years captured high-definition video of five individuals from the Magnapinna genus. With their outsized fins, these squids resemble marine flowers moving silkily across the frame. Though lone bigfin squids have been glimpsed over the decades, these rare sightings remain the kind of novelty that makes scientists jump out of their chairs.
Video
“The most interesting thing is that they saw so many of them so close together. There are published records and several unpublished observations, but I have never heard of anybody coming across more than one at a time,” said Mike Vecchione, a NOAA scientist, curator at Smithsonian National Museum of Natural History and a leading authority on squids.
While Osterhage and her team could distinguish the squids they saw in the video as bigfins, they could not ascertain the species. The Magnapinna genus consists of three species: M. atlantica, M. pacifica and M. talismani. However, to identify them from snatches of video captured thousands of meters underwater is extremely difficult.
What makes the task nearly impossible is that no adult bigfin squid specimen has ever been captured. These cephalods inhabit waters more than a mile deep: the five spotted on video were at depths of between 2 and 3 kilometers, or about 2 miles down, in what’s known as the ocean’s bathypelagic zone.
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To capture anything and bring it back alive and well from the sea’s bowels is a herculean task, so at present, scientists are content with catching them on camera. “Little is known of Bigfin Squid, and many other deep-sea cephalopods, largely due to the inaccessibility of their vast yet little explored deep-sea environments, so each sighting contributes more knowledge of these squids,” Osterhage said.
The researchers used remotely operated vehicles, or ROVs, and a towed camera in their surveys. The Great Australian Bight, a vast open bay carved off Australia’s southern coast, spans almost 46,000 square kilometers (17,800 square miles). They sighted two of the squids in 2015 on the towed camera and the other three in 2017 during ROV surveys.
During these runs, the scientists used a new way of measuring the squids with paired lasers. The technology is more accurate than trying to determine a target’s size by comparing it to nearby objects, the common way to get estimates. Using this method, they calculated that one of the squid’s arms and tentacles were about 11 times its body length.
How the squids use these extensions remains unknown. “Their sticky nature has led some to believe they are used for ‘fishing’ in order to capture food,” Osterhage said. “If this is the case, having long arms and tentacles would certainly give them more surface area to capture food.”
The distinctive elbow-like kink in its arms and tentacles is another subject of curiosity. It could be a way to prevent their spaghetti-like tentacles from getting entangled, Vecchione said. The appendages come with microscopic suckers that can land them in sticky situations. Some have been known to get stuck to submersibles.
The new videos also show the squids coiling their filaments, a behavior that has never been observed before.
Though little is known about them, researchers believe these cephalopods are found across the globe, from the Pacific to the Atlantic to the Indian Ocean. Their appearance off southern Australia supports this notion of the squids’ marine cosmopolitanism. With the new paper, the number of reports from the Southern Hemisphere has more than doubled.
In a 2001 Science paper, Vecchione and his colleagues marshaled evidence from eight sightings of bigfins. Vecchione is often called in to identify the hitherto unidentified swimming organisms. His first encounter with this particular one came after a Texas woman sent him grainy video of an enormous squid. The marine zoologist remembered jumping out of his chair: he’d expected to see the giant squid, but what he found was different from anything he’d ever seen before.
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“That such a substantial animal is common in the world’s largest ecosystem, yet has not previously been captured or observed, is an indication of how little is known about life in the deep ocean,” the 2001 paper noted.
This didn’t change in the ensuing decade. A 2010 paper termed the lack of exploration of Earth’s largest and most vibrant habitats, the expanse below 200 meters (660 feet) of the ocean’s surface, as “biodiversity’s big wet secret.”
In recent years, the specter of deep-sea mining has loomed large over the world’s oceans. Companies and countries keen to meet rising demand are eyeing mineral deposits in these remote and still pristine corners of the world. It has made research on these ecosystems a matter of even greater urgency.
In the Great Australian Bight, two massive research programs have been undertaken in the past 10 years. The surveys that captured the bigfins on video were conducted as part of the Great Australian Bight Deepwater Marine Program led by Australia’s premier science agency, CSIRO, and sponsored by Chevron Australia. The other initiative was a collaboration between CSIRO and UK-headquartered oil giant BP.
These forays uncovered 277 newly described species from the region. Though Osterhage’s team did not set out to look for the squids specifically, they were on “our wish-list of organisms we did want to see,” she said.
Scientists like Vecchione hope their work will spark further research on the enigmatic animals. However, he said he worries that despite the species’ remoteness from humans, they might still be vulnerable to human activities, especially those that generate carbon emissions.
“Probably for all of the animals in this zone, the biggest threat would be climate change,” he said. “You wouldn’t think that the deep ocean would be affected by that, but there’s increasing evidence that it is.” He added that these impacts manifested not just in temperature changes but also the availability of food.
This article was originally published on Mongabay.