Lyngbya (blue-green algae) in our waterways

Lyngbya majuscula is a toxic species of cyanobacteria, a type of blue-green algae. It is also called gumbo, snot grass, fireweed, stinging limu and mermaid’s hair. It occurs naturally in marine waterways around Moreton Bay.

How to identify Lyngbya

Lyngbya grows around beds of seagrass. It grows in fine cotton wool-like strands 10 to 30 centimetres long. These strands clump together then rise to the surface forming large floating mats.

You may see Lyngbya washed up on beaches as large black deposits. It can have a strong, unpleasant musky or fishy odour.

Causes of Lyngbya blooms

Blooms only occur during the summer months under optimal growing conditions such as:

• warmer water
• increased sunlight
• elevated levels of phosphorus, nitrogen and bio-available iron
• increases in dissolved organic matter.

Avoid contact with Lyngbya

Lyngbya can wash up on beaches in large quantities. Touching it can cause skin or eye irritation.

Beachgoers should avoid contact with all algal material on the shore or in the water where Lyngbya may be present.

What Council can do about Lyngbya

Council may be able to remove the bulk of Lyngbya that washes ashore from popular sandy beaches. Public access to beaches may close during clean-up efforts. Council may not be able to remove algae from all locations because of:

• impacts to mangroves or saltmarsh ecosystems
• operational restrictions
• beach access
• tides.

To report Lyngbya material on beaches in City of Moreton Bay, contact Council.