Will gritted roads hurt wildlife?

16 January 2011



Will gritted roads hurt wildlife?


Sarah - Well of course, because we have had to put rather a lot of salt and grit out in the roads with our sort of rather glacial winter this year. Well it's kind of a difficult question to answer because obviously, when the snow melts, it'll dissolve the salt and the salt will get washed away. So if it gets washed into something like a lake or a river, it can build up. And if you imagine what that's going to do to the wildlife in the river, it's a bit like dropping a freshwater fish into seawater, and they're not adapted to live in saltwater, so that could cause some serious issues. In terms of the animals that might happen upon the salt when it's on the road, obviously, I don't know if you have a heart to put salt out, stop slugs eating your lettuces or any of your things in your garden, Chris?

Chris - I use beer, actually.

Sarah - Yes, I've heard that that's supposed to work quite well. Well if you put salt on a slug or a snail, they sort of go all frothy and it's a bit of a cruel way to kill them. So they'll obviously have problems, but with larger animals like foxes and rabbits, although eating a lot of salt could make them quite sick, it's unlikely that they'd be able to ingest that much. A couple of studies actually that came out in the last couple of years, one from the University of Minnesota and one from the University of Toronto Scarborough, found that salt from roads in those local areas had actually contaminated local water supplies, and the Toronto study also showed that wildlife have been affected because they sort of decrease in fish in local creeks, and a decrease in aquatic species diversity. But there is a key point here that our roads are designed to drain into drains. So when the snow melts if it's on the roads, it will drain into drainage and go to a water treatment plant. So in theory, it shouldn't cause too much problems unless you use a lot of it and then it gets washed into standing water. So, it could cause problems, but no one's quite sure.

Chris - Or back into the sea or coast as many of those stone drains go into the sea at the coast, don't they? So that's quite handy because the salt just goes back to where it came from in the first place really.

Sarah - Well yes, I suppose. It's still the most cost effective way of dealing with ice and snow, and you know, people have still got to get to work and drive to school.


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