Marine algae

A bloom of the brown alga Hincksia sordida.

Cyanobacteria and algae play an important role in marine ecosystems:

  • underpinning food webs including those supporting commercial fisheries;
  • contributing to global biogeochemical (carbon, nitrogen, sulphur) cycles;
  • stabilising sediments to improve water quality; and
  • providing habitat for many invertebrate species.

Marine cyanobacteria and algae remove large amounts of carbon dioxide from seawater. Globally, there are approximately 34 000 described species of cyanobacteria and algae, but this number can be expected increase to around 350 000 species once undiscovered species are documented.

Cyanobacteria and algae are a large group of photosynthetic organisms that have evolved in aquatic environments over the last 3 billion years. Unlike terrestrial plants that evolved from a common, green algal ancestor, cyanobacteria and algae share no common ancestor and therefore, from an evolutionary viewpoint, are not related.

This unrelatedness is reflected in their classification into four of the six Kingdoms of Life on Earth: cyanobacteria (Bacteria); red and green algae (Plantae), euglenoids and dinoflagellates (Protozoa) and the brown algae, diatoms and several other major groups (Chromista).

Common species in South East Queensland

Cyanobacteria Red algae Brown Algae Green Algae Phytoplankton & seagrasses

Click on the images for details about the species that can be found in South East Queensland.