Winter is here, and millions of tons of salt are being sprayed on roads and streets across North America.
That’s 10 times the amount of salt that we’ll use for food production this year. But all that salt doesn’t just disappear with the snow in spring.
Scientists say much of the runoff ends up in nearby streams, ponds or aquifers, sometimes even flowing into lakes and rivers.
While that can potentially pollute drinking water, the effect on the environment and the creatures that live in it is much more significant.
A range of studies has found that chloride from road salt can negatively impact the survival rates of crustaceans, amphibians, fish, plants and other organisms.
Road salt that settles in soil can dehydrate and kill trees and vegetation as far as 650 ft away from the roadway.
Excess rock salt that accumulates next to roads can also attract animals such as deer and squirrels, leading to accidents that kill animals, damage vehicles and threaten driver safety.
Despite all these hazards, salt is too cheap and naturally abundant for states and municipalities to abandon. But some are experimenting with creative ways to mitigate its use.
In Muncie, Ind., road crews mix beet juice with traditional rock salt. The beet juice allows the salt to be effective at lower temperatures, reduces application rates by up to 45%, and is less corrosive on bridges and concrete.
The Minnesota Department of Transportation is pioneering the use of “living snow fences.” These natural barriers made of trees, shrubs and grasses help maintain clear roads by capturing blowing snow upwind of a problem area and storing that snow over the winter, reducing salt usage, plow times and accidents.
And in Wisconsin they use cheese brine (of course) to wet road salt so that it doesn’t bounce off the road when spread. The brine is donated by a dairy that previously disposed of it in treatment plants and has reduced salt usage by 30%.
Real bird brains
Polly wants more than just a cracker, and she knows how to get it.
While we usually think of dolphins and great apes as the brainiest animals, parrots are so clever and resourceful, they’re sometimes referred to as “feathered primates.”
One particularly devious species of parrot called keas have even figured out how to manipulate traffic to get a snack.
It all started this fall when road workers in New Zealand noticed that the traffic cones at the entrance to a one-way tunnel kept moving around when no one was looking.
After setting up surveillance cameras, they discovered that the troublemakers were actually keas, who seemed to be moving the cones into the middle of the road in order to slow down or stop motorists in the hopes of getting fed.
Traffic authorities have switched to heavier traffic cones to deter the keas, which are well known throughout the country for their destructive behavior.
The New Zealand government used to pay a bounty for these devious native birds because they would attack sheep to feed on their fatty layers.
They’re also known to damage property, particularly rubber fittings and windshield-wiper blades, and were even immortalized in a viral YouTube video trying to dismantle a police car.
Going the extra mile
Unlike the kea, salamanders are lovers, not fighters.
In fact, a recent study at Ohio State University found that these horny amphibians will go to great lengths to find just the right sex partner.
Up to 9 miles, to be precise.
In human terms, that’s like a person lightly jogging 75 miles to a date.
In addition to the incredible distance, the salamanders are also braving threatening terrain. Their journeys take them across roads, fields and streams where they risk being run over, eaten or drying out along the way.
Researchers still aren’t sure why salamanders travel so far from home to mate or how they ever got funding to run such a bizarre study.