New Delhi:
NASA’s space-based sensor has given scientists an unprecedented continuous look at the boom-bust cycles of polar phytoplanktons-self-feeding components of plankton community and a key part of oceans, seas and freshwater basin ecosystems.
Phytoplankton are considered the foundation of the ocean's food web. Commercial fisheries, marine mammals and birds all depend on the blooms, said Michael Behrenfeld from the Oregon State University's College of Agricultural Sciences.
“It's really important for us to understand what controls these boom-bust cycles and how they might change in the future, because the dynamics of plankton communities have implications for all the other organisms throughout the web," Behrenfeld said.
Phytoplanktons also play a major role in influencing Earth's carbon cycle. Through photosynthesis, they absorb a great deal of the carbon dioxide near the ocean's surface. That, in turn, allows carbon dioxide from the atmosphere to go into the ocean.
The sensor is a satellite-mounted LIDAR instrument, dubbed Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP), uses a laser beam to map the ocean's surface and immediate subsurface. This CALIOP monitored plankton in the Arctic and Antarctic ocean waters from 2006 to 2015.
This new findings helped scientists to ditch the previously held belief that blooms begin when phytoplankton growth rates reach a threshold rate and then stop when growth rates crash.
Instead, blooms start when growth rates are extremely slow, and then stop when phytoplankton growth is at its maximum but the acceleration of the bloom has hit its peak.
Not only this, the study also highlights that in Arctic waters the year-to-year changes in this constant push and pull between predator and prey has been the primary driver of change over the past 10 years. The study was published in the journal Nature Geoscience.
With Inputs from PTI
