What Is Yellow-Green Algae? Is it Dangerous?

Yellow-green algae is a rather unheard-of algae. Unlike blue-green algae, brown algae, and red algae, these yellow-green algae remain relatively unknown. Since they aren’t a cause of algal blooms, a lot of time and money hasn’t been invested into this large group of algae.

While not a lot is known about this algae, there is a little bit known about them. If you want to learn more about a unique and diverse class of algae that isn’t harming the environment, continue reading below.

What Is Yellow-Green Algae?

Yellow-green algae belong to the class of (Xanthophyceae). This class encompasses over 600 species of algae. These 600-something species are broken up into 18 families. They are then broken further into 97 genera. Each species is unique, with each species having a different form and size.

Some species may be single-celled organisms, while others are filamentous, and others are simple colonies. They are Heterokonts, which is a clade of organisms known for their stiff external hairs. They are also more commonly known as stramenopiles.

As you may have guessed, the common name of this algae comes from the colors that the algae produces. When it grows, it turns a yellowish-green color due to the pigments in the organism like xanthophylls and beta-carotene.

Like plants, this algae produces chlorophyll. However, where plants synthesize chlorophyll b, the algae produces chlorophyll a and small levels of chlorophyll c.

Originally, this yellowish algae was classified alongside green algae (Chlorophyta). This was because they had similar body organization. It also had to do with the high amount of chlorophyll a that yellow-green algae produce, like green algae. Based on molecular evidence, it appears that despite the colors and shape of the body, yellow-green algae is more closely related to brown algae (Phaeophyceae).

Where to Find These Algae?

These algae are found throughout the world. Most of the species are found in freshwater, but some survive in marine waters. They prefer to stay near the surface of the water and don’t go very deep. The most common places are right on the banks of ponds, pools, and streams, more in the muddy soil than the water.

Unlike many other algae groups, the yellow-green algae species are very sturdy. They not only live in oceans, ponds, and lakes, but in damp soil and the damp areas on tree trunks, moss, and the surface of rocks. There are even some found in salt marshes.

These are rather elusive species. Even when the algae is found in a body of water, they are only found occasionally and in small groups. In water, when this algae is present, it appears as a thin layer of soap scum right along the edges of the banks.

Interestingly, despite this, these species are incredibly important to the ecosystem. In some salt marshes, they are the main producers.

Is Yellow-Green Algae Dangerous?

There’s still a lot to learn about the yellow-green algae. At the moment, they don’t appear to be harmful to plants, animals, or humans.

Part of this is because yellow-green algae don’t appear to turn into algal blooms. Most algae and bacteria that create algal blooms aren’t initially harmful. It’s when they reproduce at incredibly fast rates that they end up causing damage to the environment and humans.

So, unless this type of algae ends up producing at rapid rates out of nowhere, it’s unlikely that it will pose any danger to people in the near future. It’s thought that they play an important role in the ecosystems they live in. In some more harsh environments, they are the base level of food in the food chain.

History of Yellow-Green Algae

Unfortunately, even looking back at yellow-green algae throughout time doesn’t provide scientists with a lot of information. In fact, there are no fossils that have been found as of yet that can be positively determined to be this specific group of algae.

It’s thought that this has more to do with a lack of information about the morphology of the algae. Scientists believe that if they study the physical appearances and forms of the algae, they’ll be better able to find fossil evidence of the algae, and therefore gather information to help them learn more about it.