These Plants Photosynthesize Deep in the Arctic Even When There’s No Light
1 min read
Summary
Most life on Earth depends on sunlight for energy, but there are some parts of the ocean that receive very little light, prompting the question of when photons are too few to support photosynthesis.
Biologists have calculated that the theoretical minimum of photons needed for photosynthesis is approximately one-hundred-thousandth of the light on a sunny day.
With the difficulty of measuring light beneath sea ice, little was known about what levels of light support productivity in such dark places.
Recently, light sensors were able to detect the first signs of the return of light at the end of winter under an ice sheet, and coincided with the first observable increase in chlorophyll (a proxy for photosynthesis) in algae.
This suggests that phytoplankton can lie dormant under the ice, waiting for enough light to photosynthesize, supporting the idea that polar oceans may host more life throughout the year than previously realised.