Exploring Biodiversity of the Deep Hawaiian Pacific Ocean with Seafloor Mapping and eDNA Technologies

As the nation’s lead mapping agency, the USGS brings a wealth of expertise as a world leader in mapping and characterizing submarine geology, geologic structure, biological resources, and related processes at and beneath the seafloor. The USGS will also be deploying emerging technologies in molecular science to investigate the biological communities living in these deep seafloor habitats. Using this coupled approach integrating biological and geological research methods, participating USGS scientists bring their expertise to support the mission of this E/V Nautilus cruise as well as to inform future research priorities in the region. 

Environmental DNA (eDNA) is a novel method that characterizes species biodiversity using trace amounts of genetic material left behind as various organisms swim through the water. It provides a cost-effective means to survey all forms of marine life, from plankton to fishes to whales, from a single water sample. Data collected by USGS scientists will offer BOEM and other expedition partners critical information about species present on the sea floor and those in the water column that link the deepwater food web to more productive surface waters. Coupled with environmental data, the eDNA data offers a detailed glimpse into the biodiversity and function of these important ecosystems.  

Seafloor mapping data (bathymetry and backscatter) are collected using a swath of sonar that pings down from the hull of ship and returns the depth and relative hardness of the seafloor below, providing a wealth of information that can be used to derive the topography and geology of the surface. The structure and composition of the seafloor is the foundation on which deep-sea habitats form and drives the oceanic currents that cycle vital nutrients and oxygen from the depths to the surface to sustain marine food webs. Accurate, modern, high-resolution bathymetric maps are therefore essential for identifying and protecting sensitive marine habitats, guiding the wise use of marine resources, safe maritime navigation, and detecting seafloor geologic hazards that could threaten infrastructure and livelihood of coastal populations. However, these maps are still extremely limited with only about 20% of the seabed currently mapped to this degree. To fill these gaps, the U.S. is supporting global advancements in ocean mapping through a consortium of federal agencies forming the National Ocean Mapping, Exploration, and Characterization Council (NOMEC). As co-chair of the NOMEC council, the USGS helps lead the charge in coordinating and implementing collaborative mapping, exploring, and characterization of the nation’s ocean waters. With this Hawaiian expedition the USGS will contribute to mapping the gaps in U.S. waters and providing insight into this understudied ecosystem through biological and geological characterizations.