Signs of a blue-green algal bloom.

Freshwater blue-green algal blooms can be recognised by a discolouration of the water, by scum on the water surface, or by an earthy or musty odour coming from the water. (Water NSW, 2021)

Blue-green algae thrives in the warm surface layer of a water body that forms, usually, from spring through to autumn throughout Australia's inland waters. Blue-green algae possess gas pockets which prevent them from sinking so that they remain in the surface layer and can access the abundant light near the water surface, leading to rapid growth.

However, algae that are toxic can only be positively identified by an expert. If you think there may be a blue-green algal bloom in a water body, you should contact either the local council or the management authority for the water body, or your local RACC.

Toxic algae can only be identified by an expert.

Important - Always act as if a waterway is polluted until confirmed otherwise.

All Bellingen Riverwatch citizen scientists must wear waterproof gloves at all times when doing water testing.

Image: Cooperative Research Centre for Water Qualtiy and Treatment, 2008

Image: Willem van Aken, CSIRO

If you come into contact with water suspected of having blue-green algae

1. Remove any affected clothing

2. Wash yourself thoroughly with clean water

3. Rinse affected wetsuits in fresh water to remove any trace of algae.

4. If you have any problems, seek medical advice.

(Health VIC, 2020)

It is important to report algal blooms as contact with the algae by recreational users can be harmful.

Potential risks.

If blue-green algae multiply to high numbers, toxins may be produced causing health problems for people, domestic animals and stock that come into contact with the algae. Humans and animals should be advised from drinking or swimming in a water body which is suspected of having an algal bloom (Water NSW, 2021).

There have been reports of skin and eye irritations, nausea, vomiting, muscle weakness or cramps by some people who have swum through algal scum or swallowed it (CSIRO, 2020).

Read more about Blue Green Algae at: www.ozgreen.org/br_algae

How to report an algal bloom.

The algal information line on 1800 999 457 provides recorded information on algal alerts.

1. To report suspected algal blooms during business hours, phone (02) 9865 2559

(Dane Clarke, Algal Coordinator, Coastal (Metropolitan and South Coast, Hunter and North Coast)

2. To report suspected algal blooms at all other times, email RACC@waternsw.com.au

Include details and any available photos of the suspected bloom. A WaterNSW RACC coordinator will respond to your inquiry at the earliest opportunity.