Scientists at Bigelow Labs in East Boothbay are studying how zooplankton help to store carbon in the ocean depths through their daily migration.
"It's the largest migration of life on Earth, and it happens every single day," said Karen Stamieszkin, a biological oceanographer at Bigelow Labs who has been studying zooplankton for years.
Stamieszkin, a senior research scientist at Bigelow Laboratory, is heading up the international team of researchers, which was funded last year by the Advanced Research Projects Agency-Energy to develop models to improve estimates of carbon transport by zooplankton.
"The reason we're interested in this as it relates to carbon cycling, or even carbon sequestration, is that when they're at the surface, they're incorporating all this surface-derived or sunlight-derived carbon into their bodies, and then they're migrating to the deeper ocean, and they're metabolizing that carbon," she said.
"They're releasing it as sinking particles, like fecal pellets. They're respiring or breathing out carbon dioxide. They're peeing, so releasing dissolved organic carbon. And then sometimes they also are dying, and they themselves become particles of sinking carbon. And so there's this injection of carbon that goes from the surface, straight to the deeper ocean, that helps carbon basically more effectively, potentially be sequestered."
Stamieszkin said there are parameters for what counts as actual carbon storage — for instance, there's a certain depth in the ocean that the carbon needs to reach. So, continuing to measure the process and discover which zooplankton go the deepest, and why, is of interest to the researchers.
Carbon capture and storage is a growing area of interest as companies become increasingly interested in purchasing carbon credits to offset their emissions. The most common type of carbon offset is usually land-based, like reforestation projects. Marine carbon sequestration is a newer field of study.
The zooplankton research team is partnering with researchers at the University of Arizona's Center for Negative Carbon Emissions to evaluate the feasibility of using the tools they're developing to verify and monetarily quantify carbon storage — but it's still a very early stage.
And, Stamieszkin emphasized that carbon capture alone won't be able to account for climate change-causing CO2 emissions; it's simply one in a suite of solutions needed to address the overall problem.
"There are studies, many, many modeling studies at this point that have shown that even if we stop emitting CO2 right now, it wouldn't be enough to get us to our [Paris Climate Agreement] targets," she said. "And there's also no indication that globally, we're ready to stop emitting CO2. And so removing carbon dioxide from the atmosphere is the next step to mitigating climate change, after curbing emissions."
"And, she added, "I will say that is like a resounding, unanimous message from scientists saying this is that removal of carbon dioxide from the atmosphere is not enough to help with the climate change problem alone. It's not an excuse to keep burning fossil fuels and emitting CO2."