Understanding the natural wonder of bioluminescence

When the conditions are just right, South Australia’s coastline can light up in an unforgettable way.

On a still night, waves can glow electric blue as they roll toward the shore. This natural phenomenon is called bioluminescence, and while it’s rare, it’s one of the most striking sights you can experience along our coast.

What is bioluminescence?

Bioluminescence is a natural process where living organisms produce light through a chemical reaction in their bodies.

In the ocean, this glow is often created by microscopic plankton called dinoflagellates and usually in South Australia by the species Noctiluca scintillans, as not all dinoflagellates emit bioluminescence.

When the water is disturbed - by waves, wind or movement - these organisms emit a flash of light, creating that distinctive neon blue or green sparkle.

Other marine life like fish, squid and tiny crustaceans can also produce light, often to:

• Deter predators
• Attract prey
• Communicate or find mates

Where can you see it in South Australia?

Bioluminescence has been spotted at several locations along the South Australian coast, although sightings are unpredictable.

Some areas where it has been observed include:

• Waitpinga and Parsons beaches (Fleurieu Peninsula)
• Middleton and Goolwa coastline
• Parts of the Yorke Peninsula
• Sections of the Eyre Peninsula coast

Because it depends on specific conditions, there’s no guarantee. But when it appears, it’s usually worth the wait.

When are you most likely to see it?

Sea sparkle is an algal bloom event which tends to occur when:

• The sea is calm and relatively warm
• There’s a build-up of plankton near the surface
• Nights are dark, with minimal moonlight or artificial lighting

In South Australia, sightings are more commonly reported during warmer months, but they can happen at any time if the conditions align.

How to spot sea sparkle

If you’re heading out to look for bioluminescence, a few simple tips can improve your chances:

• During the day - look for a red-orange algal bloom near the shore. This will indicate that a bloom of bioluminescent algae is in the area.
• Follow local reports and community updates for tips of where it may be.
• Visit the coast after sunset, once it’s fully dark
• Look for glowing wave edges or light flashes in the surf
• Let your eyes adjust to the dark—avoid using bright torches or phone lights
• Watch where the water is disturbed, such as along breaking waves

Patience is key. Sometimes the glow is subtle, and other times it’s spectacular.

Is it safe to swim?

Bioluminescence itself is usually harmless, but it’s important to be cautious as it is a type of algal bloom.

Some plankton or algal blooms may be associated with algae that can be harmful or affect water quality. Conditions also change quickly at night.

Before entering the water:

•    Check local conditions and any alerts.
•    Avoid swimming in rough surf or unfamiliar areas.
•    Never enter the ocean alone at night.

If in doubt, it’s best to enjoy the view from the shore.

Tips for photographing bioluminescence

Capturing sea sparkle can be challenging, but rewarding. To improve your chances:

• Use a tripod to keep your camera steady
• Try a long-exposure to capture more light
• Shoot in low-light settings (higher ISO, slower shutter speed)
• Avoid areas with bright artificial lighting

Protecting our coastal environments

Bioluminescence is a reminder of how unique and delicate our marine ecosystems are.

If you’re visiting coastal areas:

• Stick to marked access points
• Avoid disturbing wildlife or habitats
• Take all rubbish with you
• Follow local safety signage and advice

By treading lightly, we can help ensure these natural wonders continue to thrive.

While sea sparkle isn’t something you can plan for, it’s a powerful reminder of the beauty of South Australia’s coast, and why it’s worth protecting.