The devices are attached to the tip of bayonets fired from the front of the submarine with guns. Six gill sharks have very thick skin, which makes this method of attaching devices minimally invasive for them.
Perhaps one of the sharks’ puzzling behavior is that they occasionally venture into shallow water, despite the fact that they spend most of their lives at depths of up to 1,300 metres.
Off the coast of the Azores, about 1,200 kilometers west of Portugal, animals likely migrate to shallow areas for food. But they prefer deeper, lower-temperature waters, according to Fontes of the Universidade dos Acores. (See nine pictures of animals that live in the deep sea.)
Given that the Atlantic is expected to warm at least 1.5 degrees Celsius by 2050, six-generation sharks may not be able to withstand the temperature in shallow parts of the ocean, making it more difficult to get food, Fontes said. He’s been looking for sharks for fifteen years.
“It will be very interesting to analyze the data we get from the tags, because we can compare it with the data from colleagues in other parts of the world that we work with,” he says.
“This will allow us to gain insight into the impact of climate change and rising sea temperatures on the distribution of these animals and possibly their prey.”
Also Read: You’ve Never Heard Of These Sharks
Sea full of sharks
So far, the OceanX Azores team is pleased with the number of sharks they have come across. Pedro Afonso, who also conducts research on sharks at the Universidad dos Acores, says it’s no coincidence that they are doing well in the Azores.
Traditionally, fishing in this area has been on a small scale, and the European Union banned deep-sea shark fishing in 2012, he says. “That’s why you can go down here in a submarine and come across dozens of sharks.”
David Ebert, director of the Pacific Shark Research Center at Moss Landing Marine Laboratories in California, says he’s curious about the movement patterns of six-gill sharks in the Azores compared to those in other parts of the world.
In recent years, researchers have collected data on six-gull sharks in Hawaii, the Bahamas and the Gulf of Mexico, which allowed them to compare data on the vertical distribution of these sharks at different latitudes.
“If you only outfit one shark, it won’t say much, other than what one shark does over a period of time,” said Ebert, who was not involved with the OceanX project.
“But collecting data from a number of sharks can say a lot about their movement and behaviour.” (Take part in our test: How much do you know about the deep sea?)
Returning to the submarine, Fontes and Marquez are preparing to return to the surface of the water.
Within six hours, they had spotted seven six-gill sharks, two false golebar sharks and two gill sharks – an impressive “catch”, even for scientists who owned a submarine. They failed to equip a shark with a transmitter, but they still had several nights to try again.
“There is something surreal about sitting there and watching life go on there,” Marquez said. “It’s a huge privilege.”
This article was originally published in English at NationalGeographic.com
