November 12, 2013
Whenever I give talks to the public about our work with ROVs, I’m always asked, “How do you keep the animals alive after you collect them?” The truth is that many of the animals we collect are photographed in the lab, dissected, and preserved for further analysis onshore. Many specimens are sent to colleagues around the world. These are valuable collections that will help us answer many questions about deep-sea animals and how they live. The midwater lab has successfully kept a variety of animals alive in our seawater lab back at MBARI and gleaned information about behaviors that would be nearly impossible to study in situ.
On this expedition, Stephanie Bush is working on this with cephalopods. Stephanie is a postdoctoral fellow at MBARI working with the Monterey Bay Aquarium husbandry staff in preparation of a cephalopod exhibit set to open in April 2014. The exhibit, called Tentacles: The astounding lives of octopuses, squid, and cuttlefishes, will include many live animal exhibits and the hope is to add a deep-sea species to that list.
Needless to say, it takes a lot of careful work to keep any marine organism alive in aquaria, but deep-sea animals are especially challenging. It is very important to keep the environment conditions as close to “normal” as possible. They need dark, cold water (about five degrees Celsius) and low oxygen because the deep waters they inhabit are lower in oxygen than at the surface. Also, some of the target species inhabit the oxygen minimum zone, requiring especially low oxygen. On this expedition, we’ve collected two vampire squid (Vampyroteuthis infernalis), three Octopoteuthis deletron, and one Japetella diaphana.
We have had entire cruises when we didn’t see any of these cephalopods, so we’ve been incredibly lucky this week. Stephanie has successfully kept alive all of the collections, except for one Octopoteuthis, which actually came on board the ship already dead. You win some, you lose some.
The Western Flyer‘s wet lab has a small and dark cold room where we can keep collections. Stephanie has each animal in a plastic bag floating within coolers. She displaces oxygen in the seawater by bubbling it with nitrogen. This means Stephanie has to change out each animal’s water all week to keep it fresh and low in oxygen. Now that she has the animals’ environmental conditions under control, she has started to try to feed them. In the evenings, we conduct trawls so we have lots of small crustaceans, such as krill and shrimp, to feed them. So far, each animal has grabbed the food, but she’ll have to wait to see if they actually eat and digest it. Hopefully, you’ll see the fruits of her labor at the aquarium next spring.
Research cruises are fun but also hard work. They involve working long days and often staying up late into the night. For Stephanie, it also involves working in the cold room for long periods, so with warm clothes, hat and red headlamp, she steps into the cold room to keep these little guys alive. The next challenge, with the help of the aquarium cephalopod husbandry team, will be transferring them to aquaria back on shore and continuing to care for them for as long as possible.
—Susan von Thun