A Tasmanian tourism body has been accused of making light of a serious infrastructure issue, after suggesting visitors to Bruny Island could use dog poo bags to remove their faeces.

It was suggested tourists who were "caught short without a loo in sight" could bag up their ablutions to help keep the island clean.

Bruny Island is an increasing hit with tourists, with its combination of beaches, fresh seafood, cheese and wine and the romance of being an "island off an island".

But the influx of visitors has brought a number of infrastructure challenges.

In an article for the Bruny Island News, Destination Southern Tasmania (DST) doled out tips for a safe summer on the island.

Along with a reminder about removing litter and waste, DST had a tip for anyone who found themselves far from a toilet: "Dog poo bags are good for all kinds of poo!"

Adventure Bay on Bruny Island attracts a majority of the island's visitors. ( ABC News )

Megan Weston, the president of the Bruny Island Community Association, said she initially thought the suggestion was tongue-in-cheek, and was dismayed to discover it was serious.

"To suggest that people use a doggy poo bag when we're having major problems with people not having enough public toilets is just appalling," Ms Weston said.

She said human faeces was being found on the beach at Adventure Bay.

"It's disgraceful," she said.

"Constantly you go for a walk somewhere in the bush and you will find toilet paper."

Ms Weston said tourists were often asking to use the toilets attached to businesses, without buying anything.

"I know a couple of places today have had to put up signs saying, 'toilets for use of patrons only'," she said.

She said portaloos had been suggested, but the island really needed more permanent public toilets.

Cars lined up on the Channel Highway in Tasmania, waiting to board the ferry to Bruny Island. ( Facebook: Bruny Island Ferry Queue Public Updates/Mikey Pearson )

Kingborough Mayor Dean Winter said the suggestion of dog poo bags was not helpful.

"It was one of the most bizarre things I've ever read, totally out of step with community sentiment," he said.

Mr Winter said Bruny Island residents felt increasingly under threat from the growth in tourism.

"So in that context, it was a very poor thing for an organisation to start suggesting that," he said.

DST's Alex Heroys said the article was aimed at Bruny Island visitors, and included messages about road safety, protecting local wildlife and promoting investment in new infrastructure, including new toilets at Adventure Bay.

Island residents are concerned about faeces on the beaches. ( Supplied: Greg Faull )

"We are not suggesting that local residents use council dog poo bags to collect their own faeces or for local residents to avoid toilets," Mr Heroys said.

"In previous years, there has been concern from local residents about litter on Bruny Island, including toilet paper.

"We are asking visitors to clear up all litter after themselves and dispose of it appropriately, in tune with the expectations of the local community to maintain the beauty of Bruny Island."

There are new facilities at the Alonnah foreshore, but Ms Weston said the island only had six public toilets available 24 hours a day.

Mr Winter said the council would be upgrading toilets at Lunawanna in the next financial year, and the Parks and Wildlife Service had built new public toilets at the Neck.

"Overall there are 12 public toilets on the island, along with six tourism operators who have a number of toilets, alongside many smaller businesses that have toilets for customers on their premises," he said.