A local man disgusted by the amount of plastic at the beach estimates 85 tonnes of rubbish are on 90 Mile Beach.
Jakson Stancich, from Houhora, has a diploma in marine studies and is passionate about the marine environment.
"We are living in a pretty fragile environment up here," he said.
After seeing plastic constantly on 90 Mile Beach, Mr Stancich decided to calculate how much rubbish was on the beach, in an effort to spur clean-up action.
Using a survey method of putting a one metre square at random points on the beach, he found the amount of plastic equalled about 1kg. Extrapolated out for the approximately 85km of beach, it equalled more than 85 tonnes of rubbish, he said.
Mr Stancich said he was disgusted and embarrassed by the amount of rubbish.
"We are showing a lot of people 90 Mile Beach ... I just think it's embarrassing, I really do. Here we are 'clean, green New Zealand'. It's a lie, it really is."
Mr Stancich believed a lot of the rubbish comes from the ocean, possibly travelling from Australia and the Pacific.
"Due to the size, and the geographical shape and location of 90 Mile Beach, it acts as a huge net for the Tasman Sea's rubbish."
Most concerning is plastic which becomes weathered by the sun and the waves, eventually turning into microplastics that fish can eat, he said.
"Pieces [of plastic] can be easy to pick up but when they become small, oh my god, you will be there for ever more."
Mr Stancich said he wanted people to get on board with clean-up action.
"You need to pick it up every day over the year to make a difference. With that you also need to educate schools and people to stop buying plastic and get involved."
Far North District Council had offered a little bit of support, allowing him to dispose of any rubbish collected without charge.
Mr Stancich has also set up a group to monitor the impact of large-scale avocado orchards on Houhora Harbour.
People with ideas for cleaning up 90 Mile Beach can contact Jakson Stancich on firstname.lastname@example.org or 021-205-6953.