Hundreds of thousands of clear, squishy organisms have washed up on the Western Bay coastline from Mount Maunganui to Papamoa East.
According to marine experts, the grey, slushy mass is a collection of marine life called salps.
They are often confused for baby jellyfish or jellyfish eggs, however salps do not sting.
"Salps are the fastest reproducing animal in the ocean," Bay of Plenty Polytechnic marine studies tutor David Guccione said.
"They're multi-cellular organisms, each one of the little balls is an animal that reproduces asexually and they combine to form long chains."
Mr Guccione said people often thought salps were jellyfish eggs but jellyfish eggs were microscopic. Salps live in deep ocean water, however wind and sea currents push them to shore.
Mr Guccione said salps could wash up on shore in a long chain or as a single animal, as primarily found on Western Bay coastlines.
The salp is a clear globular mass with a coloured nucleus - the animal's stomach contents. It is about the size of an old 5c piece.
Mr Guccione said salps had scattered the Western Bay coastline for many years but there seemed to be more this year.
"They live all year round but there seems to be a lot more with the annual plankton bloom.
"Salps eat plankton, so when there's a lot of food around they reproduce really quickly."
Because of their diet, salps were a valuable part of the marine ecosystem, Mr Guccione said.
"They graze, which can help keep down the nasty plankton and ... this can potentially lessen the effect of PSP (paralytic shellfish poisoning)."
The large number of salps has not put beach users off though.
One swimmer said the salps were "gross" but they did not stop her entering the water.
Brendon Mikkelsen, a Ministry of Fisheries field operations manager for Waikato, the Bay of Plenty and the Coromandel, said only one person had enquired about the creatures and most people were not concerned by them.
