A group of sea explorers were surprised to find "sharkcanoes" just hanging out in the boiling and acidic waters of an active submarine volcano area.
Brennan Phillips led an expedition to Kavachi near the Solomon Islands in an aim to make a map of its peak and study the chemical plumes, geology and biology of the extremely dangerous environment.
In an already dangerous environment where an underwater volcanic eruption could occur any time, Phillips had least expected to see sharks. How and why the sharks got there nobody really knows.
"One of the ways you can tell that Kavachi is erupting is that you can actually hear it—both on the surface and underwater," said Phillips. They did not hear any rumbling which, when the volcano is about to erupt, can be heard even from 10 miles away. They set out to go straight to the rim of the crater.
That was where they deployed an underwater camera to take a closer look at Kavachi. While the team was looking at feeds from underwater, National Geographic Society engineer Brad Henning noticed that something was off when he saw a shadow of something they could not figure out at that moment. Just a couple of seconds after, a shark came gliding along into view.
"To see interesting biology is just a bonus," said Phillips. The team also found jellyfish, sixgill sting rays and snapper fish.
Phillips noted that this type of environment has much hotter and more acidic waters, usually erupting and spewing hot lava and ash. They cannot tell how the sharks survive. Their discovery conflicts with what most know, and that is, Kavachi usually erupts. When it does erupt, there is no way such creatures can survive.
Questions arise, such as what other types of extreme environments sharks can adapt to; whether or not these animals can "sense" when the volcano is about to erupt; and what they do when that happens. To Phillips, those are interesting questions that arose from just one—when they set out to learn more about the volcano.
Phillips is looking forward to setting up a seismic observatory and the long-term deployment of cameras in the deep sea along Kavachi.
The team's expedition to Kavachi was supported by the National Geographic Society/Watt Grants Program. Footage of the sharks was captured using the National Geographic Society's deep-sea Drop-Cam.