Science under the sea

| June 25, 2014

Doreen McVeigh ’09 “showing some Sweet Briar pride with Alvin in the hangar. I missed my 5th reunion, but I had a submersible and a flag to show some Sweet Briar spirit!”

In May, NC State doctoral student Doreen McVeigh ’09 embarked on a multi-week cruise in the Gulf of Mexico. But it wasn’t a tourist trip — in fact, McVeigh spent much of her time 2 miles below the ocean surface inside the manned submarine DSV Alvin. Along with fellow scientists, she was conducting research on the deep sea.

“The deep sea is one of the least explored areas on Earth, with new species and communities discovered nearly every time we go down and look,” she says.

The main objective of this research, she explains, was to advance understanding of connectivity in the deep sea using taxa found at cold seeps — an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs. The team focused on species occurring in the Intra-American Sea (including the Caribbean, Gulf of Mexico and Eastern Seaboard of the U.S.), from which variability in oceanographic circulation, life histories and biological genetics can be quantified.

Research conducted during the trip included a variety of tasks, such as mooring recoveries and deployments, plankton sampling, high-resolution mapping, CTD casts, expendable bathythermographs and the use of a hydrophone.

McVeigh’s team began the survey on May 21 from Gulfport, Miss., on board the R/V Atlantis, a research vessel owned by the U.S. Navy and operated by the Woods Hole Oceanographic Institution. It is one of the most sophisticated research vessels afloat and is specifically outfitted for launching and servicing Alvin, the human-occupied submersible. The current location of the R/V Atlantis is available here.

“I had the opportunity to briefly drive the submersible. The pilot must navigate the submersible through a 6-inch diameter portal and maintain a safe height above the sea floor.”

“One of the major highlights of this project is being able to go down to the ocean bottom inside Alvin, make direct observations and take samples in person,” McVeigh says.

“We know so much more about the surface of other planets than we do about the deep ocean. What is known about our deep ocean would not have been possible without technology such as Alvin.”

The submersible is small, so only three people — one pilot and two scientists — are able to go down each time.

Two miles below the surface, at the bottom of the ocean, it is pitch black and ice cold, but hospitable enough for plenty of marine life, including tube worms, clams, crabs and various kinds of fish. Encountering these creatures up close was one of many highlights for McVeigh.

Another was the trip down there.

“I personally made a dive to 1,100 meters and even had the opportunity to drive the submersible,” McVeigh says.

It was once-in-a-lifetime experience for McVeigh, who combines deep-sea larval biological and behavioral data to understand the factors that cause some populations to be more connected than others. She and her team successfully spawned adult mussels and snails and reared the larvae over the four weeks at sea.

“At the end of an Alvin dive, our team collected some tubeworms from a patch, which apparently belonged to this deep-sea octopus. In an admirable display of courage, the small octopus stared down the research team in the submersible and tried to pull the tubeworms out of Alvin’s bioboxes. It’s not clear if he was angry that we took his lawn ornaments or his lunch.”

“The opportunity to film the larvae growing and swimming as they develop provides invaluable data to make the larval model more realistic,” McVeigh says.

It also offers accurate dispersal predictions. The model outputs, she adds, will then be compared with the population genetic data from individuals from their sites to ensure the parameters confirm the genetic results.

The team returned to shore in St. Petersburg, Fla., on June 19. McVeigh anticipates finishing her studies of the population connectivity of deep-sea species in the spring of 2016.

Next summer, she and the deep-sea team will re-join the R/V Atlantis and Alvin teams to recover moorings off of the coast of South Carolina and explore more seep sites along the Southeast Atlantic.

For more photos of McVeigh’s adventure, click here.

Janika Carey

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Category: Alumnae and Development, Biology