Leaving small painted rocks along trails or hidden near city sidewalks has been a trend enjoyed by many, one that's experienced a resurgence during the pandemic.
But some wildlife experts have concerns when the little curiosities are left on coastlines, such as those with positive messages and images of hearts and waves that were recently found on the shores of Lawrencetown Beach east of Halifax.
Wildlife biologist Bob Bancroft fears local ecosystems could be affected. He said painted rocks not only take away from nature's beauty, but can also be harmful to animals in the surrounding area. Some animals could mistake them for food, he said, and eat potentially toxic material like paint and glitter.
"Rocks are so varied, just like people. I find them very interesting and I don't think painting them serves any useful purpose, if anything it degrades the natural world," said Bancroft, president of Nature Nova Scotia, an environmental group.
"Who knows what could happen if some young animal starts chewing on it."
He's not alone in his concerns. Last year, Ontario Parks saw a similar increase in the number of painted rocks being left in parks, and reminded visitors that paint forms a plastic coating.
Organic chemicals are widely used as ingredients in things like paints and varnishes. Some paint can contain volatile organic compounds or VOCs, which are harmful gases that can linger in the air in high concentrations long after the product has been used. Some of these chemicals have been known to cause cancer in animals.
Many non-toxic paints, such as water-based, latex and acrylic, are considered to have somewhat low levels of VOCs. Linda Campbell, a professor in Saint Mary's University's department of environmental science, said in an email that rocks covered in paint present a potential problem due to the chemicals used and could cause micro-particulate pollution if the paint contains plastic or other long-lasting components.
Tony Charles, director of the Saint Mary's School of Environment, said although the idea of painted rocks isn't a new thing, a large amount of them could cause concern. Painted rocks contribute to beach litter, he said, something that's already a problem for Nova Scotia.
"Birds and other wild animals on the coast are facing pressure from humans," said Charles. "Whether it's stomping on breeding areas or littering or pollutants that reach the shore, there's certainly a lot to be concerned about and all of that is without even saying the words painted rocks."
Charles said there is one positive, however, when it comes to seeing painted rocks out in the wild — getting people of different ages interested in the outdoors.
"There is that aspect of what kind of incentives can we provide our children to get them to get more into nature," said Charles. Activities like rock painting "that might attract children into nature are well worth supporting within limits."
Bancroft, on the other hand, said people of all ages can enjoy nature without altering it.
"Nature is much more complicated and interesting than any of those things. There's so much to study and so much to see," said Bancroft. "Nature is a chance to settle down, tune in your senses and start looking at what life around you is really like and feel like you're a part of."
He worries the rocks are shifted during storms and tides, and the paint can flake off and become dispersed throughout the area.
Although painted rocks may be esthetically displeasing to some and an environmental concern to others, a professor at Dalhousie's School for Resource and Environmental Studies said in the grand scheme of things they won't cause any major form of water contamination.
"The painted rocks we are seeing now likely does not contain the harmful chemicals used in paint in the past, and even if they did, when compared to the disproportionately huge quantities used on buildings, wharfs, cars, ships, etcetera, seems insignificant," Prof. Tony Walker said in an email.
Bancroft said regardless of whether the paint used is likely non-toxic, people go out into nature to enjoy it for what it is and it's best to leave it alone.
"One of the ways to stay sane right now is to get out and relax in nature," said Bancroft. "If you're having troubles, [getting out] is a wonderful thing to do. That's the one things we can still do."