The photo above shows a sample of water teeming with microscopic life.
The sample was collected in a plankton net suspended into an incoming tide for 20 minutes from a bridge over an inlet near Brunswick, Maine. It was later photographed in a lab at the Southern Maine Community College. Several diatoms (aquatic, photosynthetic plants) can be identified here.
The round, cathedral window like structure is a stepanodiscus and the connected, rectangular tubes are tabellaria. Diatoms are at the bottom of the food chain, meaning that nearly all life depends upon these creatures. They produce as much as 50 percent of the Earth’s oxygen. — Paula Ursoy and John Stetson