Besides being that ever-present nuisance in our swimming pools or ponds, we likely don’t give much thought what algae actually is.

Algae is a fascinating and necessary part of our environment, and you may be surprised to learn the complex role that algae play in our ecosystem.

What Are Algae?

One alga, many algae. Yes, ‘algae’ is the collective term for a host of organisms which are classified as neither animal, fungi nor plant. There is no simple definition for algae as this blanket term includes so many varieties, but one study defined them as follows:

“Algae is the name given to a large and diverse group of oxygenic, phototrophic, eukaryotic microorganisms. Algae are eukaryotic, which means they have a nucleus. This differentiates them from bacteria and photosynthetic Cyanobacteria. They are oxygenic phototrophs, meaning they use light as their energy source for growth and produce oxygen as a by-product, like plants.

But what distinguishes algae from plants is that algae do not have any tissue differentiation. Plants can differentiate their tissues into roots, trunks, and leaves, all very different tissue types. In contrast, algae are composed of cells that are generally all the same.”

Not an easy thing to grasp, is it? It looks like a plant, grows like a plant, in some cases is closer to an animal… of sorts, but is still neither.

Seaweed is a form of algae, albeit one of the more complex types, and strictly speaking is not classified as a plant. Microscopic phytoplankton, another algal variation, provide the food base for most marine food chains. Some algae are harvested as a nutritious fertilizer, while others provide food and shelter for small sea animals.

While this green stuff in your pool may be a headache for you, out in nature it is an essential service.

Algae needs light and oxygen and some water-borne nutrients to thrive and depriving it of one or more is the best way of managing it in the urban environment.

That, and chlorine of course.