Updated 4.56pm: Bay of Plenty beaches are being invaded by slimy, smelly bright green sea lettuce.

This summer, the regional council has received five complaints and cleaned up two Tauranga beaches, Ferguson Park and Kulim Park.

Tauranga Harbour principal advisor Bruce Gardner says there are no public health warnings in place, but people don't like it.

He says when it builds up on beaches it starts creating an amenity problem, people don't like to swim in it or walk through it.

Bruce Gardner says they monitor beaches but also rely on the public to alert them to problem areas.

"We have a regular check of all the beaches in the city and also further out into the Northern part of Tauranga Harbour as well."