A captivating phenomenon has been captured lighting up the water near Rangitoto Island in pink.
Jade Curnow shared the spectacular pictures with Newshub this week. She said they were taken just north of the island on Monday morning.
NIWA has identified the colouring as an algal bloom called "Noctiluca scintillans". Scientist Dr Matteo Chiarini said microalgae can grow more quickly during summer months, causing algal blooms.
"The rapid growth of microscopic algae may produce toxins that have harmful effects on people, fish, marine mammals, and birds, but not all red tides are harmful," Dr Chiarini told Newshub.
"Despite this, it's strongly recommended to not drink or touch the pink water and stay away from it because some red tides can actually release toxic fumes."
NIWA added, however, the pink is unlikely anything other than an "interesting natural phenomena".
"This bloom has been brought to NIWA's attention over the last few weeks," a spokesperson told Newshub.
"Noctiluca scintillans has some interesting characteristics; while it is a phytoplankton, it does use light for energy and growth, it consumes other plankton and it is bioluminescent when disturbed."