\u201cNot every wave had it. The ones closer in and breaking on the shore didn\u2019t have it. It was a bit further out. It would light up blue and run down the wave.\u201d<\/p>\n
The phenomenon, known as bioluminescence, is the product of certain species of microscopic plankton that can create light. <\/p>\n
\u201cI\u2019ve never heard about it before and I am 78,\u201d Cowell said.<\/p>\n
Large crowds have flocked to P\u0101p\u0101moa recently to see the bioluminescence. Photo \/Che Whiteley<\/p>\n
She said high tide around 9.30pm was the best time to view it on Sunday night, and while her Samsung phone couldn\u2019t capture the glow, a friend managed stunning shots with a professional camera.<\/p>\n
\u201cLots of people were down there \u2026 It\u2019s worth going to have a look.\u201d <\/p>\n
What causes the blue waves<\/p>\n
University of Waikato Professor of Coastal Science Chris Battershill<\/a> said certain species of plankton – particularly plant plankton such as dinoflagellates – can create light. <\/p>\n They do this to attract food, communicate with each other, or as a chemical response to their metabolism.<\/p>\n Disturbances in the water \u2013 a wave, a boat propeller, a dolphin swimming \u2013 triggered the metabolic response and caused them to glow.<\/p>\n Fast-warming seawater temperatures, longer and sunnier days, and a \u201cbolt\u201d of nutrients from the deep were behind the recent bloom.<\/p>\n \u201cIt\u2019s a sign summer is on the way.\u201d<\/p>\n Battershill said the bloom in P\u0101p\u0101moa was likely assisted by recent strong westerly winds.<\/p>\n Surface water pushed out to sea was replaced by an \u201cupwelling\u201d of nutrient-rich water.<\/p>\n Plankton feasting on this buffet could multiply rapidly, causing a bloom. <\/p>\n In his experience, this happened every three-to-five years, but he said it was happening more often as waters warmed. <\/p>\n Is it harmful? <\/p>\n The plankton were unlikely to harm most swimmers, though some species could cause rashes for people with sensitive skin, Battershill said.<\/p>\n If the bloom got \u201cout of control\u201d it could lead to a more toxic bloom, which could show up as a \u201cred tide\u201d, where the water would turn blood red.<\/p>\n The \u201cproductivity\u201d in the water could travel up the food chain, attracting other, larger species. <\/p>\n Tauranga scientists and divers were already seeing long strings of salps and comb jellyfish, Battershill said.<\/p>\n He said the water was warming faster than he expected this year. <\/p>\n He said the water was 17C about two weeks ago. On Monday, MetService put it at 19C. <\/p>\n Photos taken on Saturday and Sunday night of the bioluminescence at P\u0101p\u0101moa. Photo \/ Che Whiteley<\/p>\n
Chris Battershill, University of Waikato professor of coastal science. <\/p>\n