These Plants Photosynthesize Deep in the Arctic Even When There’s No Light

Most of life’s engines run on sunlight, but what happens at low light? Biologists have long been curious about just how little light photosynthesis can run on.

In winter 2020 , Clara Hoppe spent months living on a ship wedged into an ice floe, through the polar night , to study limits of photosynthesis in the dark.

Icebreaker ship RV Polarstern deliberately rammed into an ice floe and allowed to drift with its engines off through the polar night .

For months it drifted with the sea ice and served as a base for scientists studying the physics, chemistry, and biology of the Arctic ’s polar night. The team carried out two parallel sets of measurements.

By measuring the cells’ carbon-uptake rates, they were able to estimate the limits of the organisms’ capacity for photosynthesis.

Microalgae found to be ready to turn their machinery on at the very moment that spring’s first light trickled through the ice.

Researchers aren’t entirely sure how the microalgae managed to stay alive and out of dormancy through the darkest times.

The finding could rewrite our understanding of Arctic organisms’ life cycles and energy reserves.