Bioluminescent waves spotted by lucky family holidaying at Auckland’s Orewa beach

An Auckland family was treated to a show of bioluminescent waves last night while staying at their Orewa holiday home and decided to take a dip to get a closer look.

“My brother was like ‘let’s go in it,’ so he took his two kids and wife into the water,” Kane Metcalfe told 1News today. “They could see the glowing bits dripping off their hair and clothes - so they all ended up glowing.

“They had never seen anything like that before. It’s a great exclamation mark to finish their holiday,” he said, adding the visiting family flew home to the US today.

Metcalfe said he’s never encountered the phenomenon.

“My parents have had that house since I was born and have never seen this before.”

Bioluminescence occurs through a chemical reaction that produces light energy within an organism's body. Photo / Kane Metcalfe

So what causes the glowing?

Bioluminescence occurs through a chemical reaction that produces light energy within an organism’s body, which in many cases would be plankton in the ocean.

Not all plankton glow and those that do only glow sometimes.

They usually produce a blue or green light that glows stronger through movement in the waves or if people swim in the water.

Calm and warm sea conditions are usually needed as well, for the phenomenon to occur.

Some of the strongest sightings are seen during hot evenings, following rain.

While it’s not good for water quality and swimming, the plankton bloom after downpours.