What are algae?

Algae are a very diverse group of simple plants that can be found in freshwater and marine environments throughout British Columbia.

While they are often considered to be aquatic organisms, algae are found in a wide range of habitats, including:

  • In the soil
  • Growing on rocks and on snow
  • Growing in association with plants, fungi (as lichens) and with animals (such as corals).

Examples of algae viewed under a microscope

A variety of microalgae (3)

Examples of algae in the environment

Marine algae - BladderwrackMarine algae (bladderwrack)

Algae on rocks - submerged (Cladophora)Algae on rocks - submerged (Cladophora)

Algae growing on soilAlgae growing on soil

Watermelon snowAlgae growing on snow

They provide important ecosystem functions, including supporting fisheries as the base of the aquatic food chain and supplying much of the oxygen we breathe. Algae can range in size from microscopic single cells (microalgae) to large seaweeds (macroalgae). While most species are microscopic, several can form colonies or long filaments and accumulate together where they can become visible to the naked eye.

Lobaria linita from the Kitimat area

Did you know? Algae + Fungi = Lichen

This is Lobaria linita from the Kitimat area. Lobaria linita is one of the “lung lichens”, so called because they resemble lung tissue in appearance.

In Europe, cough remedies are made from lichen extract taken from this genus.

Lobaria linita is a tripartite lichen with fungal, green algal and cyanobacterial components.


Most algae contain the green pigment chlorophyll-a, is which used for capturing light energy through photosynthesis.

Some unique species have no pigment at all, some have accessory pigments for light capture, and others can even engulf and digest other algae and bacteria.

Table: Spirgoyra species
Spirogyra cells Spirogyra mat

Spirogyra cells (1)
The green algae Spirogyra longata under 200x magnification. Note the individual cells connecting as multi-cellular chains.

Spirogyra mat (2)

A mass of filamentous Spirogyra longata floating near the shore of a small lake


...previous topic

Algae Watch home page

next topic...

What is cyanobacteria (blue-green algae)?

(1) Source: https://www-cyanosite.bio.purdue.edu/

(2) Source: http://bioweb.uwlax.edu/bio203/2010/fenske_megh

(3) Source: International Network for Natural Sciences. https://innspubnet.wordpress.com/2015/06/17/local-screening-for-algal-diversity-in-relation-to-water-quality-of-district-swabi-future-prospects/

All other photos are from Ministry of Environment and Climate Change Strategy staff files.