Shoppers won't find plastic straws in Countdown stores from October 1 - they'll be off the shelves.

Countdown is removing them from all stores and replacing them with a range of alternatives including bamboo, metal and paper straws.

Sustainable Coastlines co-founder and lead Camden Howitt says plastic straws were one of the most common plastic items found on NZ beaches.

However, most of them were not coming from supermarkets.

"It's still a good step. While it is a good thing, we need individuals to say to the bars, cafes and restaurants: 'No straw thanks'. I think that's the way we'll get everyone on-board."

Countdown's move is expected to remove 11.6 million straws from circulation and the waste stream each year.

EarthSavvy founder Kristy Lorson says it was great that Countdown was phasing out the sale of plastic straws and commended the sustainable options such as reusable bamboo and metal straws.

"Straws may seem like a drop in the ocean when it comes to the problem of plastic pollution, but every step we make to move away from our disposable plastic habits is a positive one and I think turtles, in particular, will be pleased with this decision."

Christchurch city councillors want plastic straws gone by the end of 2019, and Wellington is making moves to become New Zealand's first straw-free city.

Countdown general manager of corporate affairs and sustainability Kiri Hannifin says Countdown was serious about reducing unnecessary plastic to protect the country's environment.

"Straws can have a disastrous impact on the marine environment if they end out there.”

"One of the best ways we can reduce that impact is by moving away from selling products that are used once and then thrown away."

Kiri says the single-use plastic bag phase out had already shown them New Zealanders were already changing the way they shopped.

Customers were also providing other feedback for changes regarding plastic, she says.

"We're continuing to look at where we can make changes in our own brands and are also working with our supplies to see where changes in their packaging may be possible."

In June, Countdown joined a New Zealand industry pledge towards using 100 per cent reusable, recyclable or compostable packaging in their own brands by 2025 or earlier.

Additional reporting by Stuff.