Phytoplankton and ocean plant health

Phytoplankton are microscopic plant like organisms that live in the ocean. Phytoplankton are found in oceans in abundance throughout the world and they are the foundation of the marine food chain. As they depend upon certain conditions for growth, they are a good indicator or change in their environment.

Recently, NASA’s Aqua satellite has detected a unique signal which will help the researchers check the health and productivity of ocean plants around the world.

Phytoplankton account for half of all photosynthesis activity on Earth. The health of these marine plants affects commercial fisheries, the amount of carbon dioxide the ocean can  absorb, and how the ocean  esponds to climate change. It is with the Moderate Resolution Imaging Spectroradiometer on NASA’s Aqua satellite, that scientists could observe red-light fluorescence over the open ocean.

All plants absorb energy from the Sun, typically more than they can consume through photosynthesis. The extra energy is mostly released as heat, but a small fraction is re-emitted as fluorescent light in red wavelengths. MODIS is the first instrument to observe this signal on a global scale. Red light fluorescence reveals much about the physiology of marine plants.

MODIS data brought to light a peculiar  character of the Indian Ocean, large portions of which were seen to light up seasonally with changes in monsoon winds. In the  summer, autumn and winter- particularly summer- significant southwesterly winds stir up ocean currents and bring more  nutrients up from the depths for the phytoplankton.

Over years to decades, these data can also be used to detect long-term trends in climate change and other human perturbations to the ocean. Phytoplankton reflect and react to these global changes, which can be detected by satellites like Aqua.