CORVALLIS, Ore. – As part of a NASA air and sea mission, Oregon State University researchers will measure ocean plants to see how changes in carbon levels could affect the future of fisheries and marine life.
Setting sail from Rhode Island on July 18, the Ship-Aircraft Bio-Optical Research (SABOR) campaign will use new optical instruments to pinpoint carbon levels in phytoplankton – tiny plants that play a critical role in carbon cycling. Phytoplankton absorb carbon dioxide during photosynthesis, distribute it when eaten by fish and other marine life, and then act as a carbon sink when they die and drift into the deep sea.
"Phytoplankton are the base of the marine food web and critical to the overall health of the Earth," said Mike Behrenfeld, one of the SABOR project scientists and a botany and plant pathology professor in OSU's College of Agricultural Sciences. “Changes to these microscopic plants – including the carbon they absorb – can affect an entire ocean, from sardine populations, to the location of native birds, and even to decreases in the survival of marine mammals.
"Understanding changes to phytoplankton biomass and photosynthesis are critical for projecting how oceans will fare in the future and how much of it is related to climate change," added Behrenfeld, who specializes in marine algae research.
The 20-day study has the team sailing and flying around the continental shelf off the East Coast of the United States. SABOR is unique among NASA projects because scientists will measure the ocean from both the air and water and try to find relationships between the two datasets. NASA will use the information to guide future satellite missions for understanding how the ocean and atmosphere are affected by climate.
The expedition will feature a state-of-the-art instrument that Behrenfeld's research team is using to separate phytoplankton from other particles in ocean water, such as bacteria, dead mass, and other types of plankton. The device, known as a sorting flow cytometer, uses a laser to detect phytoplankton in small streams of seawater. It then separates out the tiny plants to be analyzed for carbon. The technique is providing the first direct measurements of organic carbon in phytoplankton, said Behrenfeld.
While the Behrenfeld team is making measurements on the ship, an airplane will be collecting additional data, using an advanced laser system that can penetrate the ocean and measure phytoplankton levels in the upper depths of the water.
“By taking measurements using both the air and water instruments, scientists can gather a more accurate dataset than if they just used one or the other method," said Behrenfeld. "These relationships are the first step toward satellite technology that can provide an improved understanding of ocean ecology and its role in the carbon cycle.
"Eventually, new satellite missions will determine how and why ocean ecosystems are changing and the consequences to fish and the climate," Behrenfeld added.
The Behrenfeld research group is teaming with Kimberly Halsey, a microbiology professor with a joint appointment in OSU's College of Science and the College of Agricultural Sciences, to further understand how changes in phytoplankton numbers are related to their photosynthesis and general health. The two OSU teams include Allen Milligan, Jason Graff, Nerissa Fisher, and Matthew Brown.
SABOR is funded by the Ocean Biology and Biogeochemistry Program at NASA Headquarters, Washington. Project management and support will be provided by the Earth Science Project Office at NASA. Other mission scientists hail from the University of Maine; NASA's Langley Research Center; NASA's Goddard Institute for Space Studies; the City College of New York and others.