How do you take care of something that practically no one has ever even seen alive before?

As this ScienCentral News video reports, ocean scientists are finding it’s not easy, but it can be done.

Wonders of the Deep

One might think that we have extensive knowledge about the animals of Earth. But ongoing studies of the deep ocean show that we still have a lot to learn about the creatures of our planet—and how to care for them.

At the “Mysteries of the Deep” exhibit in the Monterey Bay Aquarium in Monterey, California, marine researchers—and the public—get to see some very unusual creatures. Ed Sidel, associate curator of the aquarium, says creating this display has been "a very difficult endeavor. We were keeping alive creatures that no one had ever seen alive before!” he says.

For example, two breeds of rockfish that are practically identical to the untrained eye—the long and the short spine thornyheads—responded quite differently when brought up from 1,200 feet deep. One lived; the other died. They discovered that a pressure-sensitive enzyme in the short spine thornyhead didn’t function at surface pressures as shallow as an exhibit tank. So how did they find a way to exhibit them? It turns out that because food is scarce at great depths, these fish have to swim to the surface to feed and grow while young. So if the aquarium caught these fish at this young stage, they survived in the exhibit.

The Monterey Bay Aquarium’s collection of deep sea creatures is the largest in the world. One reason for that is the aquarium is fortunate enough to have a deep sea canyon right in its own backyard, one of the few in the world to have such convenient access to this habitat. Second, it has spent over a decade learning the biology, care and collection of deep sea animals. Lastly, the aquarium’s sister organization, the Monterey Bay Aquarium Research Institute (MBARI), contributes the technology and leading scientists necessary to study and collect these deep sea animals.

Veronica Franklin, senior aquarist at Monterey Bay Aquarium, tends some of the strange creatures from the deep sea. “At depth, there is low light,” she says. “There’s high pressure, cold temperatures, low oxygen levels.” But in the aquarium the conditions are different—and possibly deadly to the animals. So the researchers had to do more studying.

They found that many unusual creatures from the deep—like ratfish, predatory tunicates, catsharks, and eelpouts—could survive the change in pressure that results from bringing the animals to the surface. But many of the creatures needed to be coddled in other ways.

“We have to chill the water to 43 degrees. It’s very cold!” says Franklin. They also must slowly introduce the animals to light and limit the time that they spend in it. Franklin says light can promote the growth of diatoms. "Diatoms are small microscopic plants that actually will grow on the tissues of the animals," she says. That growth could be dangerous.

Franklin says that for some of the animals, like the predatory tunicates, “too much oxygen is toxic." So they reduce the amount of oxygen in the tanks by introducing nitrogen. “The nitrogen grabs ahold of the oxygen, pulls some of the oxygen out of the water, and it produces an environment that the tunicates can survive in,” she says.

From the size of holes that lobsters live in to the feeding habits of the predatory tunicates, the marine researchers at the aquarium and MBARI have had to learn the habits and needs of the animals in order to keep them healthy and alive.

“And if we can replicate those here, then we can actually have the animals in an environment where we can observe them on a daily basis," says Franklin. "With those daily observations, you’re always learning something new about the animals. And the more we can observe the animals in some of their natural behaviors, the more we can gather information from those animals and be able to piece the puzzle together.”

Research at the Monterey Bay Aquarium and the MBARI is funded by the Monterey Bay Aquarium Foundation.