Bioluminescence Algae, Jervis Bay

‘Sea Sparkle’ or Glow in The Dark Plankton

Bioluminescent displays are one of the world’s natural wonders! There has been an amazing display recently in various parts of Jervis Bay (August 2018, May 2019, January 2020, April 2020 and early July 2020).


Some plankton or algae can glow in the dark, usually emitting a blue glow. Plankton are the diverse collection of organisms that live in large bodies of water and are unable to swim against a current or tide. They are a source of food for larger aquatic organisms such as fish. The word for organisms that glow is “bioluminescence” eg glow worms or fireflies, which comes from “bio,” or life, and “lumin,” meaning light.


Sea Sparkle or Noctiluca scintillans

One example of a microscopic bioluminescent algae that is often found in Jervis Bay is a dinoflagellate (described as having a ‘tail’) called Noctiluca, or ‘sea sparkle’. Noctiluca are so small that thousands of them can fit in a single drop of water. Bioluminescent plankton don’t glow during the day because it requires a chemical reaction powered by energy to make the glow happen all the time. The bioluminescence results from a light-producing chemical reaction where certain chemicals when mixed together produce energy which ‘excites’ other particles to vibrate and generate light which causes the glow. 

The group of chemicals involved to make plankton glow are broadly termed luciferins and the light is produced by a series of oxidation (to add oxygen) reactions set off by a catalyst called luciferase. This bioluminescence is a form of cold light or luminescence. Scientists think that Noctiluca flashes to startle or scare away its predators. The bioluminescence might also attract bigger predators, by acting as an alert and, therefore, these larger predators may eat Noctiluca’s predators. They ‘squirt’ or release glowing chemicals into the water. The light flash also can surprise the Noctiluca’s predators causing them to worry about these larger predators attacking them. Blooms (or significant amounts) of the 'sea sparkle' can be deadly to fish if it accumulates and gives off ammonia as the microalgae die.

However, the experience of walking, paddling or swimming in the midst of these amazing creatures is something that should be witnessed at least once by the avid adventurer. 

When to Look For ‘Sea Sparkles’

Time of the Year: Noctiluca scintillans is commonest in the warmer months in Jervis Bay, but may be found at any time of the year. In 2018, it was found as the weather began to warm in August. In 2019, it was found in mid May and in 2020 Late June - early July.  The best time to see bioluminescence in Jervis Bay has varied but the event has been repeated the last few years between May and August.

Time of day: Noctiluca floats easily on the surface and will concentrate on the surface if undisturbed. During the day, thick blooms of Noctiluca appear as a soft pink haze, known as the ‘red tide’ on the surface of the water, sometimes so thick that the bottom cannot even be seen in shallow water. At night, the bioluminescence is best observed in total darkness well into the evening.

Amazingly, most bioluminescent organisms – including Noctiluca – have an inbuilt biological clock that tells them when it is night-time, and they will not flash during the day, even if put into a dark room.

Weather conditions: Noctiluca is around all year but in fairly low numbers, too few to put on a light display. After a good rain, however, nutrient runoff into a main body of water acts as fertilizer, stimulating a phytoplankton bloom. Following the days which have been calm and sunny after decent rain, are usually the best nights to look for ‘Sea Sparkles’.

Gentle breezes are needed to concentrate the bloom against the shore but stronger winds will create too much turbulence on the surface and will sink and disperse the phytoplankton.

Habitat: The best places to observe ‘Sea Sparkles’ are those where there is a gentle breeze blowing them towards the shore and a protected inlet where they can accumulate. Examples of good bays would be Callala Bay, Scottish Rocks and Orion Beach in Jervis Bay.

What To Look For At Night

Noctiluca ‘sea sparkle’ emit a definite light flash (often bluish) when disturbed such as a breaking wave, footsteps along the water’s edge, a rock or sand tossed into the water, a child splashing about. Often phytoplankton cells left behind on the beach will glitter briefly on their own as do samples collected in the hands.

How To Photograph ‘SEA SPARKLES’

Camera type: Usually a camera with adjustable settings (e.g., a DSLR) will produce the best photos. In dense and widespread blooms, any camera set on long exposure will produce good images even iPhones will produce good shots under these conditions.

Settings: Use your tripod or similar and have an exposure length between 5 and 30 seconds depending on conditions.

What Safety Precautions Should I Take? 

Are they dangerous to humans? It can be dangerous to ingest Noctiluca or put it on the face, eyes, or mouth. Brief handling with your hands or running in the water will cause no ill effects.

Does it hurt them when we splash around? Splashing around doesn’t hurt them. The tide stranding them on the beach – or us stomping on them – will dry them or crush them.

The Following Photographers Regularly Capture Bioluminescence in Jervis Bay:

Also Follow Us:

Book With Us For The Holiday You Deserve in Our Jervis Bay Accommodation

You can book and pay online on our website (here) for your accommodation in Huskisson in one of our stylish 2 or 3 bedroom, 2 bathroom apartments.  Contact us directly for a great price on our accommodation in Jervis Bay.  We can also be found when people search for one of the following: Jervis Bay accommodation, Jervis Bay Vista or Bayreach 1.


You're running a web browser we don't fully support. Please upgrade it for a better experience.
Our site works best with Google Chrome.
How to upgrade the browser