— Nan Sterman
If I asked you to name the world’s largest plants, you’d probably guess the California’s coast redwoods or giant Sequoias. If I asked you to name the world’s smallest plants, what would come to mind?
The smallest plants, really the smallest plant-like organisms, are a kind of algae called phytoplankton. If you’ve swam in the ocean or in a lake, you’ve had a close encounter with phytoplankton, and you probably never noticed.
Phytoplankton are tiny, microscopic, and present in powerful numbers. Together, they are the basis of the ocean’s food chain. Phytoplankton are also responsible for generating 80% or more of the oxygen in the air we breathe.
Still, few people realize that phytoplankton, or their larger cousins the seaweeds, exist, though from time to time, they make their presence known.
“Red tides,” for example, happen from along the coast of California. The water turns red from a population explosion of a tiny red-pigmented phytoplankton that naturally live in the water, just in smaller numbers. These tiny organisms are measured on the scale of microns, so you can imagine how many there have to be to turn the ocean red.
Visit a red tide at night to see an aquatic fireworks display. Those same tiny plankton have an enzyme that literally makes light when it is agitated. So, as the waves crash, the water lights up in an eerie icy blue green. If you’ve never seen it, that’s an experience your bucket list.
The unexpected roles that phytoplankton and their cousins the seaweeds play in our day-today lives are this week’s topic on A Growing Passion. As we learn this week from Dr. Steve Mayfield at UCSD, the petroleum that fuels our cars and heats our homes is actually the accumulation of ancient algae oil. We eat algae, most obviously as the dark green sheets on the outside of sushi rolls. We eat algae extracts in ice cream, salad dressings, chocolate milk, soy milk, and many more products sold in supermarkets.
Algae are marketed as food supplements. They are used in the cosmetics industry, too. Today, scientists are developing methods to use phytoplankton as tiny biofactories for making drugs and other pharmaceuticals. UCSD’s Dr. Steve Mayfield shows us how his team is using phytoplankton to make precursors for plastics too – all in an effort to reduce our reliance on petroleum
I fell under algae’s spell when I was a college student many years ago. Their silent existence fascinated me, as did their myriad of shapes, colors, and sizes. Watch this week’s show to see why and how these tiny plants are playing bigger and surprising roles in our lives.