Scripps Oceanography research team completes 11-day expedition to deep ocean
A research team from the Scripps Institution of Oceanography in La Jolla has returned from an 11-day excursion exploring the depths of the ocean, and Lisa Levin, one of its leaders, said the mission was successful.
“We set out to study the biological and microbiological communities on the hard grounds — that means the rocks — that occur on the Southern California Borderland, the name for the very rugged terrain offshore of Los Angeles, Orange County and San Diego,” said Levin, a professor of biological oceanography at SIO since 1992.
The motivation for the expedition, which took place Oct. 27 to Nov. 6 on the ship Nautilus, an exploration vessel of the nonprofit Ocean Exploration Trust, was twofold, Levin said.
First, researchers wanted to “understand what’s there on these mineral-rich substrates, or rocks, that have been targeted by society for seabed mining.”
She said the second goal was to “understand the biopharmaceutical potential of the microbes in this area” for medicines or “potential industrial agents or other processes and products that could benefit people.”
Levin said research aboard the ship entailed creating maps every evening — bathymetric maps, “which tell us about the water depths and different typographic features,” backscatter maps, which indicate reflectivity and rocky areas, and slope maps.
The maps were used to design dive tracks for a remotely operated vehicle called Hercules, which was sent out every morning for eight hours and was monitored by the research team, with scientists directing the Hercules pilots where to go.
“We took samples of sediments, water, rocks and the microbes and animals that are associated with those,” Levin said. “What we find, in terms of biodiversity and the potential of those microbes, remains to be seen.”
Hercules went as deep as about 5,900 feet, Levin said, with the dive sites ranging from 40 to 150 miles offshore.
One of the exciting features of the trip for Levin was a “science chat” broadcast from Nautilus during which the public and scientists could ask questions of scientists interpreting the dives. “I really enjoyed that aspect,” she said.
Despite challenges such as maneuvering Hercules and difficulty finding the desired rocks, the trip was “a very relaxing week out at sea,” Levin said. She has undertaken expeditions like this before, although to different locations for different investigations.
Researchers “stumbled on a few things we weren’t expecting,” Levin said, including the fossilized skeleton of a whale embedded in rocks.
She said she also was surprised at how “heterogenous” the dive sites were. “We made eight different dives in eight places off Southern California, and every single one was different. The rocks were different, the animal communities were different, even at the same water depths.”
The trip, also led by Paul Jensen, a professor of marine biology, included a team of eight people from four SIO laboratories and took two years to plan. It was funded by the National Oceanic and Atmospheric Administration’s Office of Exploration and Research.
The trip was originally scheduled for June but was postponed by the coronavirus pandemic. Staff cutbacks restricted Hercules dives to eight hours a day instead of multiple crews piloting the vehicle 24 hours a day, Levin said.
“The hard work happens now,” Levin said, as researchers analyze video and process collected data in the lab under microscopes.
Levin said the team also “deployed experiments we plan to pick up in September” 2021 under a different project that she, Jensen and SIO marine biology professor Greg Rouse are heading.
“We put out different ... blocks of wood and different types of rock and some bone to look at the animals that colonize these different substrates,” Levin said. “We’re interested in knowing whether there are animals that prefer or avoid the rocks that we’re studying.”
“Most of the deep ocean hasn’t really been studied or explored,” she said. “It’s pretty important to know what’s there in order to manage it properly. As human pressures increase, it takes on some added urgency.”
To learn more, visit bit.ly/sionautilus. ◆
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