MOSCOW, August 6. /TASS/. The North Pole-42 drifting expedition participants explained how the internal biological clock of Arctic plankton works in complete darkness. In the polar night and the absence of sunlight, marine plankton particles establish biological rhythms based on the tides' ebb and flow, press service of the Arctic and Antarctic Research Institute (AARI) told TASS.
"Scientists have collected data on mesozooplankton concentrations and monitored their daily activity. They have demonstrated that even in the absence of sunlight in the Arctic, plankton continues to function according to its internal 'biological clock.' Spectral analysis of plankton concentrations revealed that its behavioral activity's 24-hour daily rhythm, typically associated with sunrise and sunset, persists even with the onset of polar night: the amplitude drops by approximately a third, but the rhythm still persists - the plankton continues to operate according to its internal 'biological clock.' The second rhythm -a tidal rhythm, with a period of 10.5-13 hours - is also consistently present in the spectrum. This rhythm manifests as a 'second harmonic' of the daily cycle and, apparently, helps the plankton maintain its biorhythm in the absence of light," the press service said.
