FLATHEAD LAKE – Two researchers from the University of Montana’s Flathead Lake Biological Station spent 34 days this past spring navigating the Pacific Ocean south of Hawaii as part of a research cruise to gather environmental data.
Associate Professor Matthew Church and FLBS Postdoctoral Scholar Emma Wear were aboard the University of Hawai‘i research vessel Kilo Moana to participate in the DeepCCZ Project. The researchers were exploring the mysterious deep water ecosystem known as Clarion-Clipperton Zone, or CCZ, to gather deep-sea microbial samples from the ocean floor.
The international mining community continues to develop a deep-sea mining industry, and the CCZ is a targeted spot. More than 1 million square kilometers of the abyssal Pacific seafloor have been identified for possible seafloor nodule mining. Manganese nodules are a potential source of copper, nickel, cobalt, iron, manganese and rare earth elements – metals used in electrical systems and for electronics like rechargeable batteries and touch screens.
Deep-sea nodule mining is expected to result in the destruction of marine life and seabed habitats over large areas. This destruction has the potential to occur within sites directly mined as well as in adjoining areas impacted by sediment plumes created by mining activities.
The aim of DeepCCZ Project is to learn as much about the biodiversity and species ranges across the region to develop a baseline of environmental data before mining begins. The search for this baseline drew Church and Wear into the alien realm of deep-sea microbes.
“It’s hard to fathom what it’s like to live in the abyssal sea, miles below the sunlit world we experience,” Church wrote in a mission log while on the Kilo Moana. “The darkness, cold temperatures and unrelenting high pressure make it a habitat that is completely foreign to our own. Yet lurking in this deep-sea realm is a world of microorganisms that are directly coupled to the life we know.”
Microorganisms, or microbes, are enormously diverse, ranging in size from submicron to a few microns. A human hair is, on average, about 100 microns in diameter, so hundreds of microbes lined up end-to-end might still not cross the width of a human hair. They also are the most abundant deep-sea organism, the oldest inhabitants of our planet, and over the past billion years have played a major role in shaping the habitability of our planet.
But despite their vast numbers and ecological significance, little is known about these tiny organisms. Big questions remain about what they do, how quickly they reproduce and how they interact with other organisms in the vast CCZ ecosystem. Church and Wear boarded the Kilo Moana in Hawaii in search of answers to these questions.
“We were fortunate to collaborate with an interdisciplinary group of hard-working and smart scientists during this cruise,” said Church, who heads the Church Lab for Microbial Biogeochemistry and Ecology at FLBS. “This enabled us to place our measurements on microorganism biodiversity in broader context of the biology of this unique habitat. The samples we collected represent some of the only samples of their type to be retrieved from this region of the world’s oceans.”
In many ways, their work is exploratory. While previous research focused on microorganisms living in the seawater, this was their first experience working with deep-sea sediment. During the cruise, they used a special instrument package that measured temperature, salinity and the depth of the water. It was also equipped with 24 10-liter sampling bottles that could be closed independently, giving the ability to collect samples at 24 different depths. The instrument was deployed from the ship on a conducting wire, which provided real-time data that allowed them to examine the physical and chemical structure of the water from the surface to the seabed. For sampling sediments, researchers used small coring tubes that were pushed by a remotely operated vehicle into the soft sediments, retrieving a vertical section of the mud.
With these tools at their disposal, they harvested microbes from seawater, sediments, and polymetallic nodules for subsequent analyses of nucleic acid sequences (DNA and RNA). They will use these samples to assess whether there are distinct communities of microbes in different habitats in the abyss and provide insight into the functioning of these ecosystems across the CCZ. Though the data will take months to fully analyze, it will lead to substantially better understanding of the biodiversity and ecology of the vast and poorly studied region, and the adequacy of conservation measures presently in place.
Church and those working in his lab are eager to get started.
“We are hopeful that the data we generate as part of this project will help inform future conservation efforts for this region,” Church said. “These are fragile ecosystems that are easy to ignore because they are so remote and isolated, but there remains so much to learn about the biology of these organisms.”
More information about the DeepCCZ Project can be found at https://oceanexplorer.noaa.gov/explorations/18ccz/logs/video-summary/video-summary.html. Updates on Church’s research will also be published on the Flathead Lake Biological Station website at https://flbs.umt.edu.
The DeepCCZ Expedition was funded by the Gordon and Betty Moore Foundation, the NOAA Office of Ocean Exploration and Research, the Pew Charitable Trusts and the University of Hawai‘i. In addition to UM’s Church, project principal investigators include Craig Smith, Jeff Drazen, and Erica Goetze of the University of Hawai‘I; Eric Vetter of Hawaii Pacific University; Andrew Sweetman of Heriot Watt University; UK, Adrian Glover of the Natural History Museum UK; and Thomas Dahlgren of the University of Gothenburg, Sweden.