NZ's litter problem: Citizen scientists hope rubbish data will provide wake-up call for Kiwis

In a programme being rolled out at over 100 beaches, groups of volunteers are collecting and analysing the rubbish that washes up on New Zealand shores to build a database of evidence to inspire action.

"The survey area is 100 metres by 20 metres - 10 metres above the tide line, and 10 metres below," says Shelley Butt of Sustainable Coastlines.

Volunteers around the country are collecting hard data on the rubbish washing up on our coastlines.

At first glance, many beaches may look litter-free, but on closer inspection, they are covered - and most of it is plastic.

Seventy percent of the litter is plastic.  Data shows that on beaches nationwide there are on average 420 pieces of litter per 1000 square metres, and that doesn't even include the microplastics.

The people doing the cleaning up are known as "citizen scientists" and the hope is that the evidence they collect will help us understand and solve New Zealand's litter problem.

"We're using a United Nations Environment Programme methodology, we sort that litter into 100 categories we count it and we weigh it and that provides official statistics," says Sustainable Coastlines co-founder Camden Howitt.  

It's called "Litter Intelligence", and it's already led to change - resulting in restaurants and bars ditching plastic straws.

Researching where the litter comes from, helps target the source.

One group at Waiuku College has found plastic bottle tops and food containers are a big issue.

 "Going to the supermarket is one place where you can make those decisions to avoid single-use plastics," says Howitt. 

It's no longer enough to refuse our waste, we need to refuse to create it in the first place.