Saturday, March 12, 2016

Photosynthetic Phytoplankton

Most atmospheric oxygen comes from plant-life converting the Sun's energy into chemical energy via photosynthesis.
I cannot cause light; the most I can do is try to put myself in the path of its beam.
Annie Dillard
Photosynthesis in aquatic plants like phytoplankton contributes roughtly 45% of atmospheric oxygen.
a botanical prefix derived from the Greek phyton meaning plant, flora, or vegetation.
Phytoplankton are single-celled, aquatic plants adrift and aplenty in the oceans, seas, and freshwater ecosystems. Phytoplankton are microscopic organisms that sustain aquatic animals like whales, shrimp, snails, and jellyfish.

The diatom Attheya Longicornis at 400x magnification

The main classes of phytoplankton are diatoms and dinoflagellates. Diatoms often form ribbon-shaped colonies, but with no means of propulsion, are subject to the flow of currents.

Dinoflagellates are swimmers with whip-like flagella used to propel themselves.

Whip-like tail of a dinoflagellate

All phytoplankton convert the Sun's energy into sustenance via photosynthesis within the euphotic zone. The term euphotic comes from the Greek roots for well lit: εὖ "well" + φῶς "light".
Euphotic Zone
Sunlit water extending from the water's surface to a depth where the light intensity falls to 1% of that at the surface. 
Phytoplankton thrive where sunlight can penetrate and fuel their activity. About 90% of all marine life exists in the euphotic zone.
The oxygen in today's atmosphere is almost entirely the result of photosynthetic living, which had its start with the appearance of blue-green algae among the microorganisms.
Lewis Thomas