A NASA satellite instrument orbiting Earth that can see through fog, clouds and darkness has given scientists their first continuous look at the boom-and-bust, or peak and decline, cycles of phytoplankton – foundation of the ocean’s food web vital for life to exist on earth.
The results showed that small, environmental changes in polar food webs significantly influence the boom-and-bust cycles of phytoplankton.
The researchers believe that the findings – published in the journal Nature Geoscience – will supply important data for ecosystem management, commercial fisheries and our understanding of the interactions between Earth’s climate and key ocean ecosystems.
“It’s really important for us to understand what controls these boom-and-bust cycles, and how they might change in the future so we can better evaluate the implications on all other parts of the food web,” said Michael Behrenfeld, a marine plankton expert at Oregon State University in Corvallis, US.
Coastal economies and wildlife depend on what happens to tiny green plants, or phytoplankton, at the base of the ocean food chain. Commercial fisheries, marine mammals and birds all depend on phytoplankton blooms.
Phytoplankton also influence Earth’s carbon cycle. Through photosynthesis, they absorb a great deal of the carbon dioxide dissolved in the upper ocean and produce oxygen, which is vital for life on Earth. This reduces the amount of carbon dioxide in the atmosphere.
NASA’s Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP), an instrument aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite launched in 2006, uses a laser to take measurements. Scientists used the instrument to continuously monitor plankton in polar regions from 2006 to 2015.
“CALIOP was a game-changer in our thinking about ocean remote sensing from space,” said Chris Hostetler, a research scientist at NASA’s Langley Research Center in Hampton, Virginia.
“We were able to study the workings of the high-latitude ocean ecosystem during times of year when we were previously completely blind,” Hostetler noted